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EcoSal Plus

Domain 4:

Synthesis and Processing of Macromolecules

The Sec System: Protein Export in

MyBook is a cheap paperback edition of the original book and will be sold at uniform, low price.
  • Authors: Jennine M. Crane1, and Linda L. Randall2
  • Editors: Susan T. Lovett3, Harris D. Bernstein4
    Affiliations: 1: Department of Biochemistry, University of Missouri, Columbia, MO 65201; 2: Department of Biochemistry, University of Missouri, Columbia, MO 65201; 3: Brandeis University, Waltham, MA; 4: National Institutes of Health, Bethesda, MD
  • Received 22 March 2017 Accepted 27 April 2017 Published 21 November 2017
  • Address correspondence to Linda L. Randall, [email protected]
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  • Abstract:

    In , proteins found in the periplasm or the outer membrane are exported from the cytoplasm by the general secretory, Sec, system before they acquire stably folded structure. This dynamic process involves intricate interactions among cytoplasmic and membrane proteins, both peripheral and integral, as well as lipids. , both ATP hydrolysis and proton motive force are required. Here, we review the Sec system from the inception of the field through early 2016, including biochemical, genetic, and structural data.

  • Citation: Crane J, Randall L. 2017. The Sec System: Protein Export in , EcoSal Plus 2017; doi:10.1128/ecosalplus.ESP-0002-2017


1. Redman CM, Siekevitz P, Palade GE. 1966. Synthesis and transfer of amylase in pigeon pancreatic micromosomes. J Biol Chem 241:1150–1158. [PubMed]
2. Andrews TM, Tata JR. 1971. Protein synthesis by membrane-bound and free ribosomes of secretory and non-secretory tissues. Biochem J 121:683–694. [PubMed]
3. Blobel G, Dobberstein B. 1975. Transfer of proteins across membranes. I. Presence of proteolytically processed and unprocessed nascent immunoglobulin light chains on membrane-bound ribosomes of murine myeloma. J Cell Biol 67:835–851. [PubMed]
4. Schlessinger D. 1963. Protein synthesis by polyribosomes on protoplast membranes of B. megaterium. J Mol Biol 7:569–582. [PubMed]
5. Hendler RW, Tani J. 1964. On the cytological unit for protein synthesis in vivo in E. coli. II. Studies with intact cells of type B. Biochim Biophys Acta 80:294–306. [PubMed]
6. Schlessinger D, Marchesti VT, Kwan BC. 1965. Binding of ribosomes to cytoplasmic reticulum of Bacillus megaterium. J Bacteriol 90:456–466. [PubMed]
7. Ron EZ, Kohler RE, Davis BD. 1966. Polysomes extracted from Escherichia coli by freeze-thaw-lysozyme lysis. Science 153:1119–1120. [PubMed]
8. Moore LD, Kocun FJ, Umbreit WW. 1966. Cell-free protein synthesis: effects of age and state of ribosomal aggregation. Science 154:1350–1353. [PubMed]
9. Cancedda R, Schlesinger MJ. 1974. Localization of polyribosomes containing alkaline phosphatase nascent polypeptides on membranes of Escherichia coli. J Bacteriol 117:290–301. [PubMed]
10. Randall LL, Hardy SJ. 1977. Synthesis of exported proteins by membrane-bound polysomes from Escherichia coli. Eur J Biochem 75:43–53. [PubMed]
11. Smith WP, Tai PC, Thompson RC, Davis BD. 1977. Extracellular labeling of nascent polypeptides traversing the membrane of Escherichia coli. Proc Natl Acad Sci USA 74:2830–2834. [PubMed]
12. Halegoua S, Sekizawa J, Inouye M. 1977. A new form of structural lipoprotein of outer membrane of Escherichia coli. J Biol Chem 252:2324–2330. [PubMed]
13. Sekizawa J, Inouye S, Halegoua S, Inouye M. 1977. Precursors of major outer membrane proteins of Escherichia coli. Biochem Biophys Res Commun 77:1126–1133. [PubMed]
14. Inouye H, Beckwith J. 1977. Synthesis and processing of an Escherichia coli alkaline phosphatase precursor in vitro. Proc Natl Acad Sci USA 74:1440–1444. [PubMed]
15. Randall LL, Hardy SJ, Josefsson LG. 1978. Precursors of three exported proteins in Escherichia coli. Proc Natl Acad Sci USA 75:1209–1212. [PubMed]
16. Michaelis S, Beckwith J. 1982. Mechanism of incorporation of cell envelope proteins in Escherichia coli. Annu Rev Microbiol 36:435–465. [PubMed]
17. Emr SD, Schwartz M, Silhavy TJ. 1978. Mutations altering the cellular localization of the phage lambda receptor, an Escherichia coli outer membrane protein. Proc Natl Acad Sci USA 75:5802–5806. [PubMed]
18. Bassford P, Beckwith J. 1979. Escherichia coli mutants accumulating the precursor of a secreted protein in the cytoplasm. Nature 277:538–541. [PubMed]
19. Ito K, Bassford PJ Jr, Beckwith J. 1981. Protein localization in E. coli: is there a common step in the secretion of periplasmic and outer-membrane proteins? Cell 24:707–717. [PubMed]
20. Josefsson LG, Randall LL. 1981. Different exported proteins in E. coli show differences in the temporal mode of processing in vivo. Cell 25:151–157. [PubMed]
21. Koshland D, Botstein D. 1982. Evidence for posttranslational translocation of beta-lactamase across the bacterial inner membrane. Cell 30:893–902. [PubMed]
22. Hansen W, Garcia PD, Walter P. 1986. In vitro protein translocation across the yeast endoplasmic reticulum: ATP-dependent posttranslational translocation of the prepro-alpha-factor. Cell 45:397–406. [PubMed]
23. Waters MG, Blobel G. 1986. Secretory protein translocation in a yeast cell-free system can occur posttranslationally and requires ATP hydrolysis. J Cell Biol 102:1543–1550.
24. Randall LL. 1983. Translocation of domains of nascent periplasmic proteins across the cytoplasmic membrane is independent of elongation. Cell 33:231–240.
25. Daniels CJ, Bole DG, Quay SC, Oxender DL. 1981. Role for membrane potential in the secretion of protein into the periplasm of Escherichia coli. Proc Natl Acad Sci USA 78:5396–5400. [PubMed]
26. Enequist HG, Hirst TR, Harayama S, Hardy SJ, Randall LL. 1981. Energy is required for maturation of exported proteins in Escherichia coli. Eur J Biochem 116:227–233. [PubMed]
27. Pages JM, Lazdunski C. 1982. Maturation of exported proteins in Escherichia coli. Requirement for energy, site and kinetics of processing. Eur J Biochem 124:561–566. [PubMed]
28. Zimmermann R, Wickner W. 1983. Energetics and intermediates of the assembly of Protein OmpA into the outer membrane of Escherichia coli. J Biol Chem 258:3920–3925. [PubMed]
29. Bakker EP, Randall LL. 1984. The requirement for energy during export of beta-lactamase in Escherichia coli is fulfilled by the total protonmotive force. EMBO J 3:895–900. [PubMed]
30. Chen L, Tai PC. 1985. ATP is essential for protein translocation into Escherichia coli membrane vesicles. Proc Natl Acad Sci USA 82:4384–4388. [PubMed]
31. Geller BL, Movva NR, Wickner W. 1986. Both ATP and the electrochemical potential are required for optimal assembly of pro-OmpA into Escherichia coli inner membrane vesicles. Proc Natl Acad Sci USA 83:4219–4222. [PubMed]
32. Müller M, Fisher RP, Rienhöfer-Schweer A, Hoffschulte HK. 1987. DCCD inhibits protein translocation into plasma membrane vesicles from Escherichia coli at two different steps. EMBO J 6:3855–3861. [PubMed]
33. Yamane K, Ichihara S, Mizushima S. 1987. In vitro translocation of protein across Escherichia coli membrane vesicles requires both the proton motive force and ATP. J Biol Chem 262:2358–2362. [PubMed]
34. Cabelli RJ, Chen L, Tai PC, Oliver DB. 1988. SecA protein is required for secretory protein translocation into E. coli membrane vesicles. Cell 55:683–692.
35. Cunningham K, Lill R, Crooke E, Rice M, Moore K, Wickner W, Oliver D. 1989. SecA protein, a peripheral protein of the Escherichia coli plasma membrane, is essential for the functional binding and translocation of proOmpA. EMBO J 8:955–959. [PubMed]
36. Lill R, Cunningham K, Brundage LA, Ito K, Oliver D, Wickner W. 1989. SecA protein hydrolyzes ATP and is an essential component of the protein translocation ATPase of Escherichia coli. EMBO J 8:961–966. [PubMed]
37. Randall LL, Hardy SJ. 1986. Correlation of competence for export with lack of tertiary structure of the mature species: a study in vivo of maltose-binding protein in E. coli. Cell 46:921–928.
38. Hardy SJ, Randall LL. 1991. A kinetic partitioning model of selective binding of nonnative proteins by the bacterial chaperone SecB. Science 251:439–443.
39. Park S, Liu G, Topping TB, Cover WH, Randall LL. 1988. Modulation of folding pathways of exported proteins by the leader sequence. Science 239:1033–1035. [PubMed]
40. Liu GP, Topping TB, Cover WH, Randall LL. 1988. Retardation of folding as a possible means of suppression of a mutation in the leader sequence of an exported protein. J Biol Chem 263:14790–14793. [PubMed]
41. Liu G, Topping TB, Randall LL. 1989. Physiological role during export for the retardation of folding by the leader peptide of maltose-binding protein. Proc Natl Acad Sci USA 86:9213–9217. [PubMed]
42. Beckwith J, Ferro-Novick S. 1986. Genetic studies on protein export in bacteria. Curr Top Microbiol Immunol 125:5–27. [PubMed]
43. Ellis RJ, Hemmingsen SM. 1989. Molecular chaperones: proteins essential for the biogenesis of some macromolecular structures. Trends Biochem Sci 14:339–342.
44. Delepelaire P, Wandersman C. 1998. The SecB chaperone is involved in the secretion of the Serratia marcescens HasA protein through an ABC transporter. EMBO J 17:936–944. [PubMed]
45. Debarbieux L, Wandersman C. 2001. Folded HasA inhibits its own secretion through its ABC exporter. EMBO J 20:4657–4663. [PubMed]
46. Wolff N, Sapriel G, Bodenreider C, Chaffotte A, Delepelaire P. 2003. Antifolding activity of the SecB chaperone is essential for secretion of HasA, a quickly folding ABC pathway substrate. J Biol Chem 278:38247–38253. [PubMed]
47. Sapriel G, Wandersman C, Delepelaire P. 2003. The SecB chaperone is bifunctional in Serratia marcescens: SecB is involved in the Sec pathway and required for HasA secretion by the ABC transporter. J Bacteriol 185:80–88. [PubMed]
48. Kumamoto CA, Beckwith J. 1983. Mutations in a new gene, secB,cause defective protein localization in Escherichia coli. J Bacteriol 154:253–260. [PubMed]
49. Kumamoto CA, Beckwith J. 1985. Evidence for specificity at an early step in protein export in Escherichia coli. J Bacteriol 163:267–274. [PubMed]
50. Shimizu H, Nishiyama K, Tokuda H. 1997. Expression of gpsA encoding biosynthetic sn-glycerol 3-phosphate dehydrogenase suppresses both the LB- phenotype of a secB null mutant and the cold-sensitive phenotype of a secG null mutant. Mol Microbiol 26:1013–1021. [PubMed]
51. Kumamoto CA, Nault AK. 1989. Characterization of the Escherichia coli protein-export gene secB. Gene 75:167–175. [PubMed]
52. Weiss JB, Ray PH, Bassford PJ Jr. 1988. Purified secB protein of Escherichia coli retards folding and promotes membrane translocation of the maltose-binding protein in vitro. Proc Natl Acad Sci USA 85:8978–8982. [PubMed]
53. Watanabe M, Blobel G. 1989. Cytosolic factor purified from Escherichia coli is necessary and sufficient for the export of a preprotein and is a homotetramer of SecB. Proc Natl Acad Sci USA 86:2728–2732. [PubMed]
54. Smith VF, Schwartz BL, Randall LL, Smith RD. 1996. Electrospray mass spectrometric investigation of the chaperone SecB. Protein Sci 5:488–494. [PubMed]
55. Murén EM, Suciu D, Topping TB, Kumamoto CA, Randall LL. 1999. Mutational alterations in the homotetrameric chaperone SecB that implicate the structure as dimer of dimers. J Biol Chem 274:19397–19402. [PubMed]
56. Topping TB, Woodbury RL, Diamond DL, Hardy SJ, Randall LL. 2001. Direct demonstration that homotetrameric chaperone SecB undergoes a dynamic dimer-tetramer equilibrium. J Biol Chem 276:7437–7441. [PubMed]
57. Suo Y, Hardy SJS, Randall LL. 2015. The basis of asymmetry in the SecA:SecB complex. J Mol Biol 427:887–900. [PubMed]
58. den Blaauwen T, Terpetschnig E, Lakowicz JR, Driessen AJ. 1997. Interaction of SecB with soluble SecA. FEBS Lett 416:35–38. [PubMed]
59. Randall LL, Crane JM, Lilly AA, Liu G, Mao C, Patel CN, Hardy SJ. 2005. Asymmetric binding between SecA and SecB two symmetric proteins: implications for function in export. J Mol Biol 348:479–489. [PubMed]
60. Patel CN, Smith VF, Randall LL. 2006. Characterization of three areas of interactions stabilizing complexes between SecA and SecB, two proteins involved in protein export. Protein Sci 15:1379–1386. [PubMed]
61. Fekkes P, van der Does C, Driessen AJ. 1997. The molecular chaperone SecB is released from the carboxy-terminus of SecA during initiation of precursor protein translocation. EMBO J 16:6105–6113. [PubMed]
62. Hartl FU, Lecker S, Schiebel E, Hendrick JP, Wickner W. 1990. The binding cascade of SecB to SecA to SecY/E mediates preprotein targeting to the E. coli plasma membrane. Cell 63:269–279.
63. Kumamoto CA, Francetić O. 1993. Highly selective binding of nascent polypeptides by an Escherichia coli chaperone protein in vivo. J Bacteriol 175:2184–2188. [PubMed]
64. Randall LL, Topping TB, Hardy SJ, Pavlov MY, Freistroffer DV, Ehrenberg M. 1997. Binding of SecB to ribosome-bound polypeptides has the same characteristics as binding to full-length, denatured proteins. Proc Natl Acad Sci USA 94:802–807. [PubMed]
65. Müller M, Blobel G. 1984. In vitro translocation of bacterial proteins across the plasma membrane of Escherichia coli. Proc Natl Acad Sci USA 81:7421–7425. [PubMed]
66. Hoffschulte HK, Drees B, Müller M. 1994. Identification of a soluble SecA/SecB complex by means of a subfractionated cell-free export system. J Biol Chem 269:12833–12839. [PubMed]
67. Xu Z, Knafels JD, Yoshino K. 2000. Crystal structure of the bacterial protein export chaperone secB. Nat Struct Biol 7:1172–1177. [PubMed]
68. Dekker C, de Kruijff B, Gros P. 2003. Crystal structure of SecB from Escherichia coli. J Struct Biol 144:313–319. [PubMed]
69. Volkert TL, Baleja JD, Kumamoto CA. 1999. A highly mobile C-terminal tail of the Escherichia coli protein export chaperone SecB. Biochem Biophys Res Commun 264:949–954. [PubMed]
70. Crane JM, Suo Y, Lilly AA, Mao C, Hubbell WL, Randall LL. 2006. Sites of interaction of a precursor polypeptide on the export chaperone SecB mapped by site-directed spin labeling. J Mol Biol 363:63–74. [PubMed]
71. Diamond DL, Strobel S, Chun SY, Randall LL. 1995. Interaction of SecB with intermediates along the folding pathway of maltose-binding protein. Protein Sci 4:1118–1123. [PubMed]
72. Collier DN, Bankaitis VA, Weiss JB, Bassford PJ Jr. 1988. The antifolding activity of SecB promotes the export of the E. coli maltose-binding protein. Cell 53:273–283.
73. Watanabe M, Blobel G. 1995. High-affinity binding of Escherichia coli SecB to the signal sequence region of a presecretory protein. Proc Natl Acad Sci USA 92:10133–10136. [PubMed]
74. Randall LL, Topping TB, Hardy SJ. 1990. No specific recognition of leader peptide by SecB, a chaperone involved in protein export. Science 248:860–863. [PubMed]
75. Gannon PM, Li P, Kumamoto CA. 1989. The mature portion of Escherichia coli maltose-binding protein (MBP) determines the dependence of MBP on SecB for export. J Bacteriol 171:813–818. [PubMed]
76. Lecker S, Lill R, Ziegelhoffer T, Georgopoulos C, Bassford PJ Jr, Kumamoto CA, Wickner W. 1989. Three pure chaperone proteins of Escherichia coli--SecB, trigger factor and GroEL--form soluble complexes with precursor proteins in vitro. EMBO J 8:2703–2709. [PubMed]
77. Altman E, Bankaitis VA, Emr SD. 1990. Characterization of a region in mature LamB protein that interacts with a component of the export machinery of Escherichia coli. J Biol Chem 265:18148–18153. [PubMed]
78. Weiss JB, Bassford PJ Jr. 1990. The folding properties of the Escherichia coli maltose-binding protein influence its interaction with SecB in vitro. J Bacteriol 172:3023–3029.
79. de Cock H, Overeem W, Tommassen J. 1992. Biogenesis of outer membrane protein PhoE of Escherichia coli. Evidence for multiple SecB-binding sites in the mature portion of the PhoE protein. J Mol Biol 224:369–379.
80. Randall LL, Topping TB, Suciu D, Hardy SJ. 1998. Calorimetric analyses of the interaction between SecB and its ligands. Protein Sci 7:1195–1200. [PubMed]
81. Randall LL, Hardy SJ, Topping TB, Smith VF, Bruce JE, Smith RD. 1998. The interaction between the chaperone SecB and its ligands: evidence for multiple subsites for binding. Protein Sci 7:2384–2390. [PubMed]
82. Randall LL. 1992. Peptide binding by chaperone SecB: implications for recognition of nonnative structure. Science 257:241–245. [PubMed]
83. Fekkes P, den Blaauwen T, Driessen AJ. 1995. Diffusion-limited interaction between unfolded polypeptides and the Escherichia coli chaperone SecB. Biochemistry 34:10078–10085. [PubMed]
84. Randall LL, Hardy SJ. 1995. High selectivity with low specificity: how SecB has solved the paradox of chaperone binding. Trends Biochem Sci 20:65–69.
85. Kulothungan SR, Das M, Johnson M, Ganesh C, Varadarajan R. 2009. Effect of crowding agents, signal peptide, and chaperone SecB on the folding and aggregation of E. coli maltose binding protein. Langmuir 25:6637–6648. [PubMed]
86. Knoblauch NT, Rüdiger S, Schönfeld HJ, Driessen AJ, Schneider-Mergener J, Bukau B. 1999. Substrate specificity of the SecB chaperone. J Biol Chem 274:34219–34225. [PubMed]
87. Kim J, Kendall DA. 1998. Identification of a sequence motif that confers SecB dependence on a SecB-independent secretory protein in vivo. J Bacteriol 180:1396–1401. [PubMed]
88. Vekshin NL. 1998. Protein sizes and stoichiometry in the chaperone SecB--RBPTI complex estimated by ANS fluorescence. Biochemistry (Mosc) 63:485–488.
89. Smith VF, Hardy SJ, Randall LL. 1997. Determination of the binding frame of the chaperone SecB within the physiological ligand oligopeptide-binding protein. Protein Sci 6:1746–1755. [PubMed]
90. Lilly AA, Crane JM, Randall LL. 2009. Export chaperone SecB uses one surface of interaction for diverse unfolded polypeptide ligands. Protein Sci 18:1860–1868. [PubMed]
91. Zhou Q, Sun S, Tai P, Sui S-F. 2012. Structural characterization of the complex of SecB and metallothionein-labeled proOmpA by cryo-electron microscopy. PLoS One 7:e47015. doi:10.1371/journal.pone.0047015.
92. Topping TB, Randall LL. 1994. Determination of the binding frame within a physiological ligand for the chaperone SecB. Protein Sci 3:730–736. [PubMed]
93. Khisty VJ, Munske GR, Randall LL. 1995. Mapping of the binding frame for the chaperone SecB within a natural ligand, galactose-binding protein. J Biol Chem 270:25920–25927. [PubMed]
94. Topping TB, Randall LL. 1997. Chaperone SecB from Escherichia coli mediates kinetic partitioning via a dynamic equilibrium with its ligands. J Biol Chem 272:19314–19318. [PubMed]
95. Cover WH, Ryan JP, Bassford PJ Jr, Walsh KA, Bollinger J, Randall LL. 1987. Suppression of a signal sequence mutation by an amino acid substitution in the mature portion of the maltose-binding protein. J Bacteriol 169:1794–1800. [PubMed]
96. Teschke CM, Kim J, Song T, Park S, Park C, Randall LL. 1991. Mutations that affect the folding of ribose-binding protein selected as suppressors of a defect in export in Escherichia coli. J Biol Chem 266:11789–11796. [PubMed]
97. Khisty VJ, Randall LL. 1995. Demonstration in vivo that interaction of maltose-binding protein with SecB is determined by a kinetic partitioning. J Bacteriol 177:3277–3282.
98. Chun SY, Strobel S, Bassford P Jr, Randall LL. 1993. Folding of maltose-binding protein. Evidence for the identity of the rate-determining step in vivo and in vitro. J Biol Chem 268:20855–20862. [PubMed]
99. Krishnan B, Kulothungan SR, Patra AK, Udgaonkar JB, Varadarajan R. 2009. SecB-mediated protein export need not occur via kinetic partitioning. J Mol Biol 385:1243–1256. [PubMed]
100. Wagaman AS, Coburn A, Brand-Thomas I, Dash B, Jaswal SS. 2014. A comprehensive database of verified experimental data on protein folding kinetics. Protein Sci 23:1808–1812. [PubMed]
101. Cayley S, Lewis BA, Guttman HJ, Record MT Jr. 1991. Characterization of the cytoplasm of Escherichia coli K-12 as a function of external osmolarity. Implications for protein-DNA interactions in vivo. J Mol Biol 222:281–300. [PubMed]
102. Zhou HX, Rivas G, Minton AP. 2008. Macromolecular crowding and confinement: biochemical, biophysical, and potential physiological consequences. Annu Rev Biophys 37:375–397. [PubMed]
103. Kumar M, Mommer MS, Sourjik V. 2010. Mobility of cytoplasmic, membrane, and DNA-binding proteins in Escherichia coli. Biophys J 98:552–559. [PubMed]
104. Kusukawa N, Yura T, Ueguchi C, Akiyama Y, Ito K. 1989. Effects of mutations in heat-shock genes groES and groEL on protein export in Escherichia coli. EMBO J 8:3517–3521. [PubMed]
105. Kim J, Lee Y, Kim C, Park C. 1992. Involvement of SecB, a chaperone, in the export of ribose-binding protein. J Bacteriol 174:5219–5227. [PubMed]
106. Strobel SM, Cannon JG, Bassford PJ Jr. 1993. Regions of maltose-binding protein that influence SecB-dependent and SecA-dependent export in Escherichia coli. J Bacteriol 175:6988–6995. [PubMed]
107. Gouridis G, Karamanou S, Gelis I, Kalodimos CG, Economou A. 2009. Signal peptides are allosteric activators of the protein translocase. Nature 462:363–367. [PubMed]
108. Cooper DB, Smith VF, Crane JM, Roth HC, Lilly AA, Randall LL. 2008. SecA, the motor of the secretion machine, binds diverse partners on one interactive surface. J Mol Biol 382:74–87. [PubMed]
109. Kimura E, Akita M, Matsuyama S, Mizushima S. 1991. Determination of a region in SecA that interacts with presecretory proteins in Escherichia coli. J Biol Chem 266:6600–6606. [PubMed]
110. Papanikou E, Karamanou S, Baud C, Frank M, Sianidis G, Keramisanou D, Kalodimos CG, Kuhn A, Economou A. 2005. Identification of the preprotein binding domain of SecA. J Biol Chem 280:43209–43217. [PubMed]
111. Gelis I, Bonvin AMJJ, Keramisanou D, Koukaki M, Gouridis G, Karamanou S, Economou A, Kalodimos CG. 2007. Structural basis for signal-sequence recognition by the translocase motor SecA as determined by NMR. Cell 131:756–769. [PubMed]
112. Musial-Siwek M, Rusch SL, Kendall DA. 2007. Selective photoaffinity labeling identifies the signal peptide binding domain on SecA. J Mol Biol 365:637–648. [PubMed]
113. Francetić O, Kumamoto CA. 1996. Escherichia coli SecB stimulates export without maintaining export competence of ribose-binding protein signal sequence mutants. J Bacteriol 178:5954–5959. [PubMed]
114. Kim J, Miller A, Wang L, Müller JP, Kendall DA. 2001. Evidence that SecB enhances the activity of SecA. Biochemistry 40:3674–3680. [PubMed]
115. Baars L, Ytterberg AJ, Drew D, Wagner S, Thilo C, van Wijk KJ, de Gier J-W. 2006. Defining the role of the Escherichia coli chaperone SecB using comparative proteomics. J Biol Chem 281:10024–10034. [PubMed]
116. Phillips GJ, Silhavy TJ. 1990. Heat-shock proteins DnaK and GroEL facilitate export of LacZ hybrid proteins in E. coli. Nature 344:882–884. [PubMed]
117. Ito K, Akiyama Y, Yura T, Shiba K. 1986. Diverse effects of the MalE-LacZ hybrid protein on Escherichia coli cell physiology. J Bacteriol 167:201–204. [PubMed]
118. Wild J, Walter WA, Gross CA, Altman E. 1993. Accumulation of secretory protein precursors in Escherichia coli induces the heat shock response. J Bacteriol 175:3992–3997. [PubMed]
119. Altman E, Kumamoto CA, Emr SD. 1991. Heat-shock proteins can substitute for SecB function during protein export in Escherichia coli. EMBO J 10:239–245. [PubMed]
120. Wild J, Altman E, Yura T, Gross CA. 1992. DnaK and DnaJ heat shock proteins participate in protein export in Escherichia coli. Genes Dev 6:1165–1172. [PubMed]
121. Fröderberg L, Houben EN, Baars L, Luirink J, de Gier JW. 2004. Targeting and translocation of two lipoproteins in Escherichia coli via the SRP/Sec/YidC pathway. J Biol Chem 279:31026–31032. [PubMed]
122. Bochkareva ES, Lissin NM, Girshovich AS. 1988. Transient association of newly synthesized unfolded proteins with the heat-shock GroEL protein. Nature 336:254–257. [PubMed]
123. Laminet AA, Ziegelhoffer T, Georgopoulos C, Plückthun A. 1990. The Escherichia coli heat shock proteins GroEL and GroES modulate the folding of the beta-lactamase precursor. EMBO J 9:2315–2319. [PubMed]
124. Randall LL, Hardy SJ. 2002. SecB, one small chaperone in the complex milieu of the cell. Cell Mol Life Sci 59:1617–1623. [PubMed]
125. The Rolling Stones. 1969. You Can’t Always Get What You Want. Decca Records London Records.
126. Müller JP. 1996. Influence of impaired chaperone or secretion function on SecB production in Escherichia coli. J Bacteriol 178:6097–6104. [PubMed]
127. Panse VG, Vogel P, Trommer WE, Varadarajan R. 2000. A thermodynamic coupling mechanism for the disaggregation of a model peptide substrate by chaperone secB. J Biol Chem 275:18698–18703. [PubMed]
128. Ullers RS, Luirink J, Harms N, Schwager F, Georgopoulos C, Genevaux P. 2004. SecB is a bona fide generalized chaperone in Escherichia coli. Proc Natl Acad Sci USA 101:7583–7588. [PubMed]
129. Gannon PM, Kumamoto CA. 1993. Mutations of the molecular chaperone protein SecB which alter the interaction between SecB and maltose-binding protein. J Biol Chem 268:1590–1595. [PubMed]
130. Kimsey HH, Dagarag MD, Kumamoto CA. 1995. Diverse effects of mutation on the activity of the Escherichia coli export chaperone SecB. J Biol Chem 270:22831–22835. [PubMed]
131. Rajapandi T, Oliver D. 1994. Carboxy-terminal region of Escherichia coli SecA ATPase is important to promote its protein translocation activity in vivo. Biochem Biophys Res Commun 200:1477–1483. [PubMed]
132. Breukink E, Nouwen N, van Raalte A, Mizushima S, Tommassen J, de Kruijff B. 1995. The C terminus of SecA is involved in both lipid binding and SecB binding. J Biol Chem 270:7902–7907. [PubMed]
133. Fekkes P, de Wit JG, van der Wolk JP, Kimsey HH, Kumamoto CA, Driessen AJ. 1998. Preprotein transfer to the Escherichia coli translocase requires the co-operative binding of SecB and the signal sequence to SecA. Mol Microbiol 29:1179–1190. [PubMed]
134. Fekkes P, de Wit JG, Boorsma A, Friesen RH, Driessen AJ. 1999. Zinc stabilizes the SecB binding site of SecA. Biochemistry 38:5111–5116. [PubMed]
135. Zhou J, Xu Z. 2003. Structural determinants of SecB recognition by SecA in bacterial protein translocation. Nat Struct Biol 10:942–947. [PubMed]
136. Matousek WM, Alexandrescu AT. 2004. NMR structure of the C-terminal domain of SecA in the free state. Biochim Biophys Acta 1702:163–171. [PubMed]
137. Dempsey BR, Wrona M, Moulin JM, Gloor GB, Jalilehvand F, Lajoie G, Shaw GS, Shilton BH. 2004. Solution NMR structure and X-ray absorption analysis of the C-terminal zinc-binding domain of the SecA ATPase. Biochemistry 43:9361–9371. [PubMed]
138. Woodbury RL, Topping TB, Diamond DL, Suciu D, Kumamoto CA, Hardy SJ, Randall LL. 2000. Complexes between protein export chaperone SecB and SecA. Evidence for separate sites on SecA providing binding energy and regulatory interactions. J Biol Chem 275:24191–24198.
139. Randall LL, Crane JM, Liu G, Hardy SJ. 2004. Sites of interaction between SecA and the chaperone SecB, two proteins involved in export. Protein Sci 13:1124–1133. [PubMed]
140. Suo Y, Hardy SJS, Randall LL. 2011. Orientation of SecA and SecB in complex, derived from disulfide cross-linking. J Bacteriol 193:190–196. [PubMed]
141. Mao C, Hardy SJS, Randall LL. 2009. Maximal efficiency of coupling between ATP hydrolysis and translocation of polypeptides mediated by SecB requires two protomers of SecA. J Bacteriol 191:978–984. [PubMed]
142. Panse VG, Beena K, Philipp R, Trommer WE, Vogel PD, Varadarajan R. 2001. Electron spin resonance and fluorescence studies of the bound-state conformation of a model protein substrate to the chaperone SecB. J Biol Chem 276:33681–33688. [PubMed]
143. Haimann MM, Akdogan Y, Philipp R, Varadarajan R, Hinderberger D, Trommer WE. 2011. Conformational changes of the chaperone SecB upon binding to a model substrate – bovine pancreatic trypsin inhibitor (BPTI). Biol Chem 392:849–858. [PubMed]
144. Cabelli RJ, Dolan KM, Qian LP, Oliver DB. 1991. Characterization of membrane-associated and soluble states of SecA protein from wild-type and SecA51(TS) mutant strains of Escherichia coli. J Biol Chem 266:24420–24427. [PubMed]
145. Ulbrandt ND, London E, Oliver DB. 1992. Deep penetration of a portion of Escherichia coli SecA protein into model membranes is promoted by anionic phospholipids and by partial unfolding. J Biol Chem 267:15184–15192. [PubMed]
146. Chen X, Xu H, Tai PC. 1996. A significant fraction of functional SecA is permanently embedded in the membrane. SecA cycling on and off the membrane is not essential during protein translocation. J Biol Chem 271:29698–29706. [PubMed]
147. Ramamurthy V, Oliver D. 1997. Topology of the integral membrane form of Escherichia coli SecA protein reveals multiple periplasmically exposed regions and modulation by ATP binding. J Biol Chem 272:23239–23246. [PubMed]
148. Chen X, Brown T, Tai PC. 1998. Identification and characterization of protease-resistant SecA fragments: secA has two membrane-integral forms. J Bacteriol 180:527–537. [PubMed]
149. Morita K, Tokuda H, Nishiyama K. 2012. Multiple SecA molecules drive protein translocation across a single translocon with SecG inversion. J Biol Chem 287:455–464. [PubMed]
150. Woodbury RL, Hardy SJ, Randall LL. 2002. Complex behavior in solution of homodimeric SecA. Protein Sci 11:875–882. [PubMed]
151. Wowor AJ, Yu D, Kendall DA, Cole JL. 2011. Energetics of SecA dimerization. J Mol Biol 408:87–98. [PubMed]
152. Rhoads DB, Waters FB, Epstein W. 1976. Cation transport in Escherichia coli. VIII. Potassium transport mutants. J Gen Physiol 67:325–341. [PubMed]
153. Castle AM, Macnab RM, Shulman RG. 1986. Measurement of intracellular sodium concentration and sodium transport in Escherichia coli by 23Na nuclear magnetic resonance. J Biol Chem 261:3288–3294. [PubMed]
154. Castle AM, Macnab RM, Shulman RG. 1986. Coupling between the sodium and proton gradients in respiring Escherichia coli cells measured by 23Na and 31P nuclear magnetic resonance. J Biol Chem 261:7797–7806. [PubMed]
155. Doyle SM, Braswell EH, Teschke CM. 2000. SecA folds via a dimeric intermediate. Biochemistry 39:11667–11676. [PubMed]
156. Benach J, Chou YT, Fak JJ, Itkin A, Nicolae DD, Smith PC, Wittrock G, Floyd DL, Golsaz CM, Gierasch LM, Hunt JF. 2003. Phospholipid-induced monomerization and signal-peptide-induced oligomerization of SecA. J Biol Chem 278:3628–3638. [PubMed]
157. Or E, Navon A, Rapoport T. 2002. Dissociation of the dimeric SecA ATPase during protein translocation across the bacterial membrane. EMBO J 21:4470–4479.
158. Duong F. 2003. Binding, activation and dissociation of the dimeric SecA ATPase at the dimeric SecYEG translocase. EMBO J 22:4375–4384. [PubMed]
159. Hunt JF, Weinkauf S, Henry L, Fak JJ, McNicholas P, Oliver DB, Deisenhofer J. 2002. Nucleotide control of interdomain interactions in the conformational reaction cycle of SecA. Science 297:2018–2026. [PubMed]
160. Sharma V, Arockiasamy A, Ronning DR, Savva CG, Holzenburg A, Braunstein M, Jacobs WR Jr, Sacchettini JC. 2003. Crystal structure of Mycobacterium tuberculosis SecA, a preprotein translocating ATPase. Proc Natl Acad Sci USA 100:2243–2248. [PubMed]
161. Zimmer J, Li W, Rapoport TA. 2006. A novel dimer interface and conformational changes revealed by an X-ray structure of B. subtilis SecA. J Mol Biol 364:259–265. [PubMed]
162. Vassylyev DG, Mori H, Vassylyeva MN, Tsukazaki T, Kimura Y, Tahirov TH, Ito K. 2006. Crystal structure of the translocation ATPase SecA from Thermus thermophilus reveals a parallel, head-to-head dimer. J Mol Biol 364:248–258. [PubMed]
163. Papanikolau Y, Papadovasilaki M, Ravelli RB, McCarthy AA, Cusack S, Economou A, Petratos K. 2007. Structure of dimeric SecA, the Escherichia coli preprotein translocase motor. J Mol Biol 366:1545–1557. [PubMed]
164. Osborne AR, Clemons WM Jr, Rapoport TA. 2004. A large conformational change of the translocation ATPase SecA. Proc Natl Acad Sci USA 101:10937–10942. [PubMed]
165. Karamanou S, Vrontou E, Sianidis G, Baud C, Roos T, Kuhn A, Politou AS, Economou A. 1999. A molecular switch in SecA protein couples ATP hydrolysis to protein translocation. Mol Microbiol 34:1133–1145. [PubMed]
166. Zimmer J, Nam Y, Rapoport TA. 2008. Structure of a complex of the ATPase SecA and the protein-translocation channel. Nature 455:936–943. [PubMed]
167. Zimmer J, Rapoport TA. 2009. Conformational flexibility and peptide interaction of the translocation ATPase SecA. J Mol Biol 394:606–612. [PubMed]
168. Chen Y, Bauer BW, Rapoport TA, Gumbart JC. 2015. Conformational changes of the clamp of the protein translocation ATPase SecA. J Mol Biol 427:2348–2359. [PubMed]
169. Das S, Grady LM, Michtavy J, Zhou Y, Cohan FM, Hingorani MM, Oliver DB. 2012. The variable subdomain of Escherichia coli SecA functions to regulate SecA ATPase activity and ADP release. J Bacteriol 194:2205–2213. [PubMed]
170. Auclair SM, Oliver DB, Mukerji I. 2013. Defining the solution state dimer structure of Escherichia coli SecA using Förster resonance energy transfer. Biochemistry 52:2388–2401. [PubMed]
171. Yu D, Wowor AJ, Cole JL, Kendall DA. 2013. Defining the Escherichia coli SecA dimer interface residues through in vivo site-specific photo-cross-linking. J Bacteriol 195:2817–2825. [PubMed]
172. Lill R, Dowhan W, Wickner W. 1990. The ATPase activity of SecA is regulated by acidic phospholipids, SecY, and the leader and mature domains of precursor proteins. Cell 60:271–280.
173. van Voorst F, Vereyken IJ, de Kruijff B. 2000. The high affinity ATP binding site modulates the SecA-precursor interaction. FEBS Lett 486:57–62. [PubMed]
174. Auclair SM, Moses JP, Musial-Siwek M, Kendall DA, Oliver DB, Mukerji I. 2010. Mapping of the signal peptide-binding domain of Escherichia coli SecA using Förster resonance energy transfer. Biochemistry 49:782–792. [PubMed]
175. Zhang Q, Li Y, Olson R, Mukerji I, Oliver D. 2016. Conserved SecA signal peptide-binding site revealed by engineered protein chimeras and Förster resonance energy transfer. Biochemistry 55:1291–1300. [PubMed]
176. Story RM, Li H, Abelson JN. 2001. Crystal structure of a DEAD box protein from the hyperthermophile Methanococcus jannaschii. Proc Natl Acad Sci USA 98:1465–1470. [PubMed]
177. Mitchell C, Oliver D. 1993. Two distinct ATP-binding domains are needed to promote protein export by Escherichia coli SecA ATPase. Mol Microbiol 10:483–497. [PubMed]
178. Chou YT, Swain JF, Gierasch LM. 2002. Functionally significant mobile regions of Escherichia coli SecA ATPase identified by NMR. J Biol Chem 277:50985–50990. [PubMed]
179. Keramisanou D, Biris N, Gelis I, Sianidis G, Karamanou S, Economou A, Kalodimos CG. 2006. Disorder-order folding transitions underlie catalysis in the helicase motor of SecA. Nat Struct Mol Biol 13:594–602. [PubMed]
180. Mori H, Ito K. 2006. The long alpha-helix of SecA is important for the ATPase coupling of translocation. J Biol Chem 281:36249–36256. [PubMed]
181. Price A, Economou A, Duong F, Wickner W. 1996. Separable ATPase and membrane insertion domains of the SecA subunit of preprotein translocase. J Biol Chem 271:31580–31584. [PubMed]
182. Sianidis G, Karamanou S, Vrontou E, Boulias K, Repanas K, Kyrpides N, Politou AS, Economou A. 2001. Cross-talk between catalytic and regulatory elements in a DEAD motor domain is essential for SecA function. EMBO J 20:961–970. [PubMed]
183. Snyders S, Ramamurthy V, Oliver D. 1997. Identification of a region of interaction between Escherichia coli SecA and SecY proteins. J Biol Chem 272:11302–11306. [PubMed]
184. Karamanou S, Gouridis G, Papanikou E, Sianidis G, Gelis I, Keramisanou D, Vrontou E, Kalodimos CG, Economou A. 2007. Preprotein-controlled catalysis in the helicase motor of SecA. EMBO J 26:2904–2914. [PubMed]
185. Fak JJ, Itkin A, Ciobanu DD, Lin EC, Song XJ, Chou YT, Gierasch LM, Hunt JF. 2004. Nucleotide exchange from the high-affinity ATP-binding site in SecA is the rate-limiting step in the ATPase cycle of the soluble enzyme and occurs through a specialized conformational state. Biochemistry 43:7307–7327. [PubMed]
186. Kourtz L, Oliver D. 2000. Tyr-326 plays a critical role in controlling SecA-preprotein interaction. Mol Microbiol 37:1342–1356. [PubMed]
187. Bowler MW, Montgomery MG, Leslie AG, Walker JE. 2006. How azide inhibits ATP hydrolysis by the F-ATPases. Proc Natl Acad Sci USA 103:8646–8649. [PubMed]
188. Breyton C, Haase W, Rapoport TA, Kühlbrandt W, Collinson I. 2002. Three-dimensional structure of the bacterial protein-translocation complex SecYEG. Nature 418:662–665. [PubMed]
189. Van den Berg B, Clemons WM Jr, Collinson I, Modis Y, Hartmann E, Harrison SC, Rapoport TA. 2004. X-ray structure of a protein-conducting channel. Nature 427:36–44. [PubMed]
190. Egea PF, Stroud RM. 2010. Lateral opening of a translocon upon entry of protein suggests the mechanism of insertion into membranes. Proc Natl Acad Sci USA 107:17182–17187. [PubMed]
191. Tsukazaki T, Mori H, Fukai S, Ishitani R, Mori T, Dohmae N, Perederina A, Sugita Y, Vassylyev DG, Ito K, Nureki O. 2008. Conformational transition of Sec machinery inferred from bacterial SecYE structures. Nature 455:988–991. [PubMed]
192. Li W, Schulman S, Boyd D, Erlandson K, Beckwith J, Rapoport TA. 2007. The plug domain of the SecY protein stabilizes the closed state of the translocation channel and maintains a membrane seal. Mol Cell 26:511–521. [PubMed]
193. Park E, Ménétret JF, Gumbart JC, Ludtke SJ, Li W, Whynot A, Rapoport TA, Akey CW. 2014. Structure of the SecY channel during initiation of protein translocation. Nature 506:102–106. [PubMed]
194. Bonardi F, Halza E, Walko M, Du Plessis F, Nouwen N, Feringa BL, Driessen AJM. 2011. Probing the SecYEG translocation pore size with preproteins conjugated with sizable rigid spherical molecules. Proc Natl Acad Sci USA 108:7775–7780. [PubMed]
195. Saparov SM, Erlandson K, Cannon K, Schaletzky J, Schulman S, Rapoport TA, Pohl P. 2007. Determining the conductance of the SecY protein translocation channel for small molecules. Mol Cell 26:501–509. [PubMed]
196. Knyazev DG, Winter L, Bauer BW, Siligan C, Pohl P. 2014. Ion conductivity of the bacterial translocation channel SecYEG engaged in translocation. J Biol Chem 289:24611–24616. [PubMed]
197. Schatz PJ, Bieker KL, Ottemann KM, Silhavy TJ, Beckwith J. 1991. One of three transmembrane stretches is sufficient for the functioning of the SecE protein, a membrane component of the E. coli secretion machinery. EMBO J 10:1749–1757. [PubMed]
198. Nishiyama K, Mizushima S, Tokuda H. 1992. The carboxyl-terminal region of SecE interacts with SecY and is functional in the reconstitution of protein translocation activity in Escherichia coli. J Biol Chem 267:7170–7176. [PubMed]
199. Bostina M, Mohsin B, Kühlbrandt W, Collinson I. 2005. Atomic model of the E. coli membrane-bound protein translocation complex SecYEG. J Mol Biol 352:1035–1043. [PubMed]
200. Erlandson KJ, Miller SB, Nam Y, Osborne AR, Zimmer J, Rapoport TA. 2008. A role for the two-helix finger of the SecA ATPase in protein translocation. Nature 455:984–987. [PubMed]
201. Ding H, Mukerji I, Oliver D. 2003. Nucleotide and phospholipid-dependent control of PPXD and C-domain association for SecA ATPase. Biochemistry 42:13468–13475. [PubMed]
202. Gold VA, Whitehouse S, Robson A, Collinson I. 2013. The dynamic action of SecA during the initiation of protein translocation. Biochem J 449:695–705. [PubMed]
203. Gold VA, Robson A, Clarke AR, Collinson I. 2007. Allosteric regulation of SecA: magnesium-mediated control of conformation and activity. J Biol Chem 282:17424–17432. [PubMed]
204. Robson A, Gold VA, Hodson S, Clarke AR, Collinson I. 2009. Energy transduction in protein transport and the ATP hydrolytic cycle of SecA. Proc Natl Acad Sci USA 106:5111–5116. [PubMed]
205. Bauer BW, Rapoport TA. 2009. Mapping polypeptide interactions of the SecA ATPase during translocation. Proc Natl Acad Sci USA 106:20800–20805. [PubMed]
206. Tanaka Y, Sugano Y, Takemoto M, Mori T, Furukawa A, Kusakizako T, Kumazaki K, Kashima A, Ishitani R, Sugita Y, Nureki O, Tsukazaki T. 2015. Crystal structures of SecYEG in lipidic cubic phase elucidate a precise resting and a peptide-bound state. Cell Rep 13:1561–1568. [PubMed]
207. Hizlan D, Robson A, Whitehouse S, Gold VA, Vonck J, Mills D, Kühlbrandt W, Collinson I. 2012. Structure of the SecY complex unlocked by a preprotein mimic. Cell Rep 1:21–28. [PubMed]
208. Osborne AR, Rapoport TA. 2007. Protein translocation is mediated by oligomers of the SecY complex with one SecY copy forming the channel. Cell 129:97–110. [PubMed]
209. Deville K, Gold VAM, Robson A, Whitehouse S, Sessions RB, Baldwin SA, Radford SE, Collinson I. 2011. The oligomeric state and arrangement of the active bacterial translocon. J Biol Chem 286:4659–4669. [PubMed]
210. Li L, Park E, Ling J, Ingram J, Ploegh H, Rapoport TA. 2016. Crystal structure of a substrate-engaged SecY protein-translocation channel. Nature 531:395–399. [PubMed]
211. Akimaru J, Matsuyama S, Tokuda H, Mizushima S. 1991. Reconstitution of a protein translocation system containing purified SecY, SecE, and SecA from Escherichia coli. Proc Natl Acad Sci USA 88:6545–6549. [PubMed]
212. Brundage L, Hendrick JP, Schiebel E, Driessen AJ, Wickner W. 1990. The purified E. coli integral membrane protein SecY/E is sufficient for reconstitution of SecA-dependent precursor protein translocation. Cell 62:649–657.
213. Nishiyama K, Mizushima S, Tokuda H. 1993. A novel membrane protein involved in protein translocation across the cytoplasmic membrane of Escherichia coli. EMBO J 12:3409–3415. [PubMed]
214. Hanada M, Nishiyama K, Tokuda H. 1996. SecG plays a critical role in protein translocation in the absence of the proton motive force as well as at low temperature. FEBS Lett 381:25–28.
215. Economou A, Wickner W. 1994. SecA promotes preprotein translocation by undergoing ATP-driven cycles of membrane insertion and deinsertion. Cell 78:835–843. [PubMed]
216. Eichler J, Wickner W. 1998. The SecA subunit of Escherichia coli preprotein translocase is exposed to the periplasm. J Bacteriol 180:5776–5779. [PubMed]
217. Schiebel E, Driessen AJ, Hartl FU, Wickner W. 1991. Delta mu H+ and ATP function at different steps of the catalytic cycle of preprotein translocase. Cell 64:927–939.
218. Nishiyama K, Suzuki T, Tokuda H. 1996. Inversion of the membrane topology of SecG coupled with SecA-dependent preprotein translocation. Cell 85:71–81. [PubMed]
219. Nagamori S, Nishiyama K, Tokuda H. 2002. Membrane topology inversion of SecG detected by labeling with a membrane-impermeable sulfhydryl reagent that causes a close association of SecG with SecA. J Biochem 132:629–634. [PubMed]
220. Kawasaki S, Mizushima S, Tokuda H. 1993. Membrane vesicles containing overproduced SecY and SecE exhibit high translocation ATPase activity and countermovement of protons in a SecA- and presecretory protein-dependent manner. J Biol Chem 268:8193–8198. [PubMed]
221. Sugai R, Takemae K, Tokuda H, Nishiyama K. 2007. Topology inversion of SecG is essential for cytosolic SecA-dependent stimulation of protein translocation. J Biol Chem 282:29540–29548. [PubMed]
222. van der Sluis EO, van der Vries E, Berrelkamp G, Nouwen N, Driessen AJ. 2006. Topologically fixed SecG is fully functional. J Bacteriol 188:1188–1190. [PubMed]
223. Moser M, Nagamori S, Huber M, Tokuda H, Nishiyama K. 2013. Glycolipozyme MPIase is essential for topology inversion of SecG during preprotein translocation. Proc Natl Acad Sci USA 110:9734–9739. [PubMed]
224. Nishiyama K, Maeda M, Yanagisawa K, Nagase R, Komura H, Iwashita T, Yamagaki T, Kusumoto S, Tokuda H, Shimamoto K. 2012. MPIase is a glycolipozyme essential for membrane protein integration. Nat Commun 3:1260. doi:10.1038/ncomms2267.
225. Mori H, Sugiyama H, Yamanaka M, Sato K, Tagaya M, Mizushima S. 1998. Amino-terminal region of SecA is involved in the function of SecG for protein translocation into Escherichia coli membrane vesicles. J Biochem 124:122–129. [PubMed]
226. Gardel C, Benson S, Hunt J, Michaelis S, Beckwith J. 1987. secD, a new gene involved in protein export in Escherichia coli. J Bacteriol 169:1286–1290. [PubMed]
227. Gardel C, Johnson K, Jacq A, Beckwith J. 1990. The secD locus of E. coli codes for two membrane proteins required for protein export. EMBO J 9:3209–3216. [PubMed]
228. Pogliano JA, Beckwith J. 1994. SecD and SecF facilitate protein export in Escherichia coli. EMBO J 13:554–561. [PubMed]
229. Duong F, Wickner W. 1997. The SecDFyajC domain of preprotein translocase controls preprotein movement by regulating SecA membrane cycling. EMBO J 16:4871–4879. [PubMed]
230. Nouwen N, Driessen AJM. 2002. SecDFyajC forms a heterotetrameric complex with YidC. Mol Microbiol 44:1397–1405. [PubMed]
231. Matsuyama S, Fujita Y, Sagara K, Mizushima S. 1992. Overproduction, purification and characterization of SecD and SecF, integral membrane components of the protein translocation machinery of Escherichia coli. Biochim Biophys Acta 1122:77–84. [PubMed]
232. Xie K, Kiefer D, Nagler G, Dalbey RE, Kuhn A. 2006. Different regions of the nonconserved large periplasmic domain of Escherichia coli YidC are involved in the SecF interaction and membrane insertase activity. Biochemistry 45:13401–13408. [PubMed]
233. Tsukazaki T, Mori H, Echizen Y, Ishitani R, Fukai S, Tanaka T, Perederina A, Vassylyev DG, Kohno T, Maturana AD, Ito K, Nureki O. 2011. Structure and function of a membrane component SecDF that enhances protein export. Nature 474:235–238. [PubMed]
234. Pogliano KJ, Beckwith J. 1994. Genetic and molecular characterization of the Escherichia coli secD operon and its products. J Bacteriol 176:804–814. [PubMed]
235. Mio K, Tsukazaki T, Mori H, Kawata M, Moriya T, Sasaki Y, Ishitani R, Ito K, Nureki O, Sato C. 2014. Conformational variation of the translocon enhancing chaperone SecDF. J Struct Funct Genomics 15:107–115. [PubMed]
236. Zgurskaya HI, Nikaido H. 1999. Bypassing the periplasm: reconstitution of the AcrAB multidrug efflux pump of Escherichia coli. Proc Natl Acad Sci USA 96:7190–7195. [PubMed]
237. Seeger MA, von Ballmoos C, Verrey F, Pos KM. 2009. Crucial role of Asp408 in the proton translocation pathway of multidrug transporter AcrB: evidence from site-directed mutagenesis and carbodiimide labeling. Biochemistry 48:5801–5812. [PubMed]
238. Tokuda H, Kim YJ, Mizushima S. 1990. In vitro protein translocation into inverted membrane vesicles prepared from Vibrio alginolyticus is stimulated by the electrochemical potential of Na+ in the presence of Escherichia coli SecA. FEBS Lett 264:10–12.
239. Ishii E, Chiba S, Hashimoto N, Kojima S, Homma M, Ito K, Akiyama Y, Mori H. 2015. Nascent chain-monitored remodeling of the Sec machinery for salinity adaptation of marine bacteria. Proc Natl Acad Sci USA 112:E5513–E5522. [PubMed]
240. Gardel C, Johnson K, Jacq A, Beckwith J. 1990. The secD locus of E. coli codes for two membrane proteins required for protein export. EMBO J 9:4205–4206. [PubMed]
241. Tani K, Shiozuka K, Tokuda H, Mizushima S. 1989. In vitro analysis of the process of translocation of OmpA across the Escherichia coli cytoplasmic membrane. A translocation intermediate accumulates transiently in the absence of the proton motive force. J Biol Chem 264:18582–18588. [PubMed]
242. Tani K, Tokuda H, Mizushima S. 1990. Translocation of ProOmpA possessing an intramolecular disulfide bridge into membrane vesicles of Escherichia coli. Effect of membrane energization. J Biol Chem 265:17341–17347. [PubMed]
243. Nouwen N, Driessen AJM. 2005. Inactivation of protein translocation by cold-sensitive mutations in the yajC-secDF operon. J Bacteriol 187:6852–6855. [PubMed]
244. Arkowitz RA, Wickner W. 1994. SecD and SecF are required for the proton electrochemical gradient stimulation of preprotein translocation. EMBO J 13:954–963. [PubMed]
245. Nouwen N, van der Laan M, Driessen AJM. 2001. SecDFyajC is not required for the maintenance of the proton motive force. FEBS Lett 508:103–106. [PubMed]
246. Matsuyama S, Fujita Y, Mizushima S. 1993. SecD is involved in the release of translocated secretory proteins from the cytoplasmic membrane of Escherichia coli. EMBO J 12:265–270. [PubMed]
247. Geller BL. 1990. Electrochemical potential releases a membrane-bound secretion intermediate of maltose-binding protein in Escherichia coli. J Bacteriol 172:4870–4876. [PubMed]
248. Ueguchi C, Ito K. 1990. Escherichia coli sec mutants accumulate a processed immature form of maltose-binding protein (MBP), a late-phase intermediate in MBP export. J Bacteriol 172:5643–5649. [PubMed]
249. Economou A, Pogliano JA, Beckwith J, Oliver DB, Wickner W. 1995. SecA membrane cycling at SecYEG is driven by distinct ATP binding and hydrolysis events and is regulated by SecD and SecF. Cell 83:1171–1181. [PubMed]
250. Duong F, Wickner W. 1997. Distinct catalytic roles of the SecYE, SecG and SecDFyajC subunits of preprotein translocase holoenzyme. EMBO J 16:2756–2768. [PubMed]
251. Saier MH Jr. 2006. Protein secretion and membrane insertion systems in gram-negative bacteria. J Membr Biol 214:75–90. [PubMed]
252. Törnroth-Horsefield S, Gourdon P, Horsefield R, Brive L, Yamamoto N, Mori H, Snijder A, Neutze R. 2007. Crystal structure of AcrB in complex with a single transmembrane subunit reveals another twist. Structure 15:1663–1673. [PubMed]
253. Emr SD, Hanley-Way S, Silhavy TJ. 1981. Suppressor mutations that restore export of a protein with a defective signal sequence. Cell 23:79–88. [PubMed]
254. Bankaitis VA, Bassford PJ Jr. 1985. Proper interaction between at least two components is required for efficient export of proteins to the Escherichia coli cell envelope. J Bacteriol 161:169–178. [PubMed]
255. Stader J, Gansheroff LJ, Silhavy TJ. 1989. New suppressors of signal-sequence mutations, prlG, are linked tightly to the secE gene of Escherichia coli. Genes Dev 3:1045–1052. [PubMed]
256. Bost S, Belin D. 1997. prl mutations in the Escherichia coli secG gene. J Biol Chem 272:4087–4093. [PubMed]
257. Osborne RS, Silhavy TJ. 1993. PrlA suppressor mutations cluster in regions corresponding to three distinct topological domains. EMBO J 12:3391–3398. [PubMed]
258. Flower AM, Doebele RC, Silhavy TJ. 1994. PrlA and PrlG suppressors reduce the requirement for signal sequence recognition. J Bacteriol 176:5607–5614. [PubMed]
259. van der Wolk JP, Fekkes P, Boorsma A, Huie JL, Silhavy TJ, Driessen AJ. 1998. PrlA4 prevents the rejection of signal sequence defective preproteins by stabilizing the SecA-SecY interaction during the initiation of translocation. EMBO J 17:3631–3639. [PubMed]
260. Derman AI, Puziss JW, Bassford PJ Jr, Beckwith J. 1993. A signal sequence is not required for protein export in prlA mutants of Escherichia coli. EMBO J 12:879–888. [PubMed]
261. Pérez-Pérez J, Barbero JL, Márquez G, Gutiérrez J. 1996. Different PrlA proteins increase the efficiency of periplasmic production of human interleukin-6 in Escherichia coli. J Biotechnol 49:245–247.
262. Nouwen N, de Kruijff B, Tommassen J. 1996. prlA suppressors in Escherichia coli relieve the proton electrochemical gradient dependency of translocation of wild-type precursors. Proc Natl Acad Sci USA 93:5953–5957. [PubMed]
263. Duong F, Wickner W. 1999. The PrlA and PrlG phenotypes are caused by a loosened association among the translocase SecYEG subunits. EMBO J 18:3263–3270. [PubMed]
264. Nishiyama K, Fukuda A, Morita K, Tokuda H. 1999. Membrane deinsertion of SecA underlying proton motive force-dependent stimulation of protein translocation. EMBO J 18:1049–1058. [PubMed]
265. Cannon KS, Or E, Clemons WM Jr, Shibata Y, Rapoport TA. 2005. Disulfide bridge formation between SecY and a translocating polypeptide localizes the translocation pore to the center of SecY. J Cell Biol 169:219–225. [PubMed]
266. Uchida K, Mori H, Mizushima S. 1995. Stepwise movement of preproteins in the process of translocation across the cytoplasmic membrane of Escherichia coli. J Biol Chem 270:30862–30868. [PubMed]
267. Whitehouse S, Gold VA, Robson A, Allen WJ, Sessions RB, Collinson I. 2012. Mobility of the SecA 2-helix-finger is not essential for polypeptide translocation via the SecYEG complex. J Cell Biol 199:919–929. [PubMed]
268. Liang F-C, Bageshwar UK, Musser SM. 2009. Bacterial Sec protein transport is rate-limited by precursor length: a single turnover study. Mol Biol Cell 20:4256–4266. [PubMed]
269. Liang F-C, Bageshwar UK, Musser SM. 2012. Position-dependent effects of polylysine on Sec protein transport. J Biol Chem 287:12703–12714. [PubMed]
270. Driessen AJ, Wickner W. 1991. Proton transfer is rate-limiting for translocation of precursor proteins by the Escherichia coli translocase. Proc Natl Acad Sci USA 88:2471–2475.
271. Joly JC, Leonard MR, Wickner WT. 1994. Subunit dynamics in Escherichia coli preprotein translocase. Proc Natl Acad Sci USA 91:4703–4707. [PubMed]
272. Boy D, Koch H-G. 2009. Visualization of distinct entities of the SecYEG translocon during translocation and integration of bacterial proteins. Mol Biol Cell 20:1804–1815. [PubMed]
273. Sanganna Gari RR, Frey NC, Mao C, Randall LL, King GM. 2013. Dynamic structure of the translocon SecYEG in membrane: direct single molecule observations. J Biol Chem 288:16848–16854. [PubMed]
274. Scheuring J, Braun N, Nothdurft L, Stumpf M, Veenendaal AK, Kol S, van der Does C, Driessen AJ, Weinkauf S. 2005. The oligomeric distribution of SecYEG is altered by SecA and translocation ligands. J Mol Biol 354:258–271. [PubMed]
275. Park E, Rapoport TA. 2012. Bacterial protein translocation requires only one copy of the SecY complex in vivo. J Cell Biol 198:881–893. [PubMed]
276. Zheng Z, Blum A, Banerjee T, Wang Q, Dantis V, Oliver D. 2016. Determination of the oligomeric state of SecYEG protein secretion channel complex using in vivo photo- and disulfide-crosslinking. J Biol Chem 291:5997–6010. 10.1074/jbc.M115.694844. [PubMed]
277. Dalal K, Chan CS, Sligar SG, Duong F. 2012. Two copies of the SecY channel and acidic lipids are necessary to activate the SecA translocation ATPase. Proc Natl Acad Sci USA 109:4104–4109. [PubMed]
278. Kedrov A, Kusters I, Krasnikov VV, Driessen AJ. 2011. A single copy of SecYEG is sufficient for preprotein translocation. EMBO J 30:4387–4397. [PubMed]
279. Schulze RJ, Komar J, Botte M, Allen WJ, Whitehouse S, Gold VA, Lycklama A, Nijeholt JA, Huard K, Berger I, Schaffitzel C, Collinson I. 2014. Membrane protein insertion and proton-motive-force-dependent secretion through the bacterial holo-translocon SecYEG–SecDF–YajC–YidC. Proc Natl Acad Sci USA 111:4844–4849. [PubMed]
280. Mao C, Cheadle CE, Hardy SJS, Lilly AA, Suo Y, Sanganna Gari RR, King GM, Randall LL. 2013. Stoichiometry of SecYEG in the active translocase of Escherichia coli varies with precursor species. Proc Natl Acad Sci USA 110:11815–11820. [PubMed]
281. Antonoaea R, Fürst M, Nishiyama K, Müller M. 2008. The periplasmic chaperone PpiD interacts with secretory proteins exiting from the SecYEG translocon. Biochemistry 47:5649–5656. [PubMed]
282. Sachelaru I, Petriman N-A, Kudva R, Koch H-G. 2014. Dynamic interaction of the sec translocon with the chaperone PpiD. J Biol Chem 289:21706–21715. [PubMed]
283. Maddalo G, Stenberg-Bruzell F, Götzke H, Toddo S, Björkholm P, Eriksson H, Chovanec P, Genevaux P, Lehtiö J, Ilag LL, Daley DO. 2011. Systematic analysis of native membrane protein complexes in Escherichia coli. J Proteome Res 10:1848–1859. [PubMed]
284. Götzke H, Palombo I, Muheim C, Perrody E, Genevaux P, Kudva R, Müller M, Daley DO. 2014. YfgM is an ancillary subunit of the SecYEG translocon in Escherichia coli. J Biol Chem 289:19089–19097. [PubMed]
285. Scotti PA, Urbanus ML, Brunner J, de Gier JW, von Heijne G, van der Does C, Driessen AJ, Oudega B, Luirink J. 2000. YidC, the Escherichia coli homologue of mitochondrial Oxa1p, is a component of the Sec translocase. EMBO J 19:542–549. [PubMed]
286. Seoh HK, Tai PC. 1997. Carbon source-dependent synthesis of SecB, a cytosolic chaperone involved in protein translocation across Escherichia coli membranes. J Bacteriol 179:1077–1081.
287. Ito K, Wittekind M, Nomura M, Shiba K, Yura T, Miura A, Nashimoto H. 1983. A temperature-sensitive mutant of E. coli exhibiting slow processing of exported proteins. Cell 32:789–797. [PubMed]
288. Downing WL, Sullivan SL, Gottesman ME, Dennis PP. 1990. Sequence and transcriptional pattern of the essential Escherichia coli secE-nusG operon. J Bacteriol 172:1621–1627. [PubMed]
289. Yang C-K, Lu C-D, Tai PC. 2013. Differential expression of secretion machinery during bacterial growth: SecY and SecF decrease while SecA increases during transition from exponential phase to stationary phase. Curr Microbiol 67:682–687. [PubMed]
290. Nakatogawa H, Murakami A, Ito K. 2004. Control of SecA and SecM translation by protein secretion. Curr Opin Microbiol 7:145–150. [PubMed]
291. Oliver DB, Beckwith J. 1982. Regulation of a membrane component required for protein secretion in Escherichia coli. Cell 30:311–319.
292. Rollo EE, Oliver DB. 1988. Regulation of the Escherichia coli secA gene by protein secretion defects: analysis of secA, secB, secD, and secY mutants. J Bacteriol 170:3281–3282. [PubMed]
293. Schmidt MG, Rollo EE, Grodberg J, Oliver DB. 1988. Nucleotide sequence of the secA gene and secA(Ts) mutations preventing protein export in Escherichia coli. J Bacteriol 170:3404–3414. [PubMed]
294. Oliver D, Norman J, Sarker S. 1998. Regulation of Escherichia coli secA by cellular protein secretion proficiency requires an intact gene X signal sequence and an active translocon. J Bacteriol 180:5240–5242. [PubMed]
295. Silber KR, Keiler KC, Sauer RT. 1992. Tsp: a tail-specific protease that selectively degrades proteins with nonpolar C termini. Proc Natl Acad Sci USA 89:295–299. [PubMed]
296. Hara H, Yamamoto Y, Higashitani A, Suzuki H, Nishimura Y. 1991. Cloning, mapping, and characterization of the Escherichia coli prc gene, which is involved in C-terminal processing of penicillin-binding protein 3. J Bacteriol 173:4799–4813. [PubMed]
297. Nakatogawa H, Ito K. 2001. Secretion monitor, SecM, undergoes self-translation arrest in the cytosol. Mol Cell 7:185–192. [PubMed]
298. Nakatogawa H, Ito K. 2002. The ribosomal exit tunnel functions as a discriminating gate. Cell 108:629–636. [PubMed]
299. Mitra K, Schaffitzel C, Fabiola F, Chapman MS, Ban N, Frank J. 2006. Elongation arrest by SecM via a cascade of ribosomal RNA rearrangements. Mol Cell 22:533–543. [PubMed]
300. Bhushan S, Hoffmann T, Seidelt B, Frauenfeld J, Mielke T, Berninghausen O, Wilson DN, Beckmann R. 2011. SecM-stalled ribosomes adopt an altered geometry at the peptidyl transferase center. PLoS Biol 9:e1000581. doi:10.1371/journal.pbio.1000581.
301. Butkus ME, Prundeanu LB, Oliver DB. 2003. Translocon “pulling” of nascent SecM controls the duration of its translational pause and secretion-responsive secA regulation. J Bacteriol 185:6719–6722. [PubMed]
302. Sarker S, Oliver D. 2002. Critical regions of secM that control its translation and secretion and promote secretion-specific secA regulation. J Bacteriol 184:2360–2369. [PubMed]
303. Sarker S, Rudd KE, Oliver D. 2000. Revised translation start site for secM defines an atypical signal peptide that regulates Escherichia coli secA expression. J Bacteriol 182:5592–5595. [PubMed]
304. Yap MN, Bernstein HD. 2011. The translational regulatory function of SecM requires the precise timing of membrane targeting. Mol Microbiol 81:540–553. [PubMed]
305. Nakatogawa H, Murakami A, Mori H, Ito K. 2005. SecM facilitates translocase function of SecA by localizing its biosynthesis. Genes Dev 19:436–444. [PubMed]
306. You Z, Liao M, Zhang H, Yang H, Pan X, Houghton JE, Sui SF, Tai PC. 2013. Phospholipids induce conformational changes of SecA to form membrane-specific domains: AFM structures and implication on protein-conducting channels. PLoS One 8:e72560. doi:10.1371/journal.pone.0072560.
307. Seoh HK, Tai PC. 1999. Catabolic repression of secB expression is positively controlled by cyclic AMP (cAMP) receptor protein-cAMP complexes at the transcriptional level. J Bacteriol 181:1892–1899. [PubMed]
308. Müller JP. 1999. Effects of pre-protein overexpression on SecB synthesis in Escherichia coli. FEMS Microbiol Lett 176:219–227. [PubMed]
309. Kumamoto CA, Chen L, Fandl J, Tai PC. 1989. Purification of the Escherichia coli secB gene product and demonstration of its activity in an in vitro protein translocation system. J Biol Chem 264:2242–2249. [PubMed]
310. Matsuyama S, Akimaru J, Mizushima S. 1990. SecE-dependent overproduction of SecY in Escherichia coli. Evidence for interaction between two components of the secretory machinery. FEBS Lett 269:96–100. [PubMed]
311. Sagara K, Matsuyama S, Mizushima S. 1994. SecF stabilizes SecD and SecY, components of the protein translocation machinery of the Escherichia coli cytoplasmic membrane. J Bacteriol 176:4111–4116. [PubMed]
312. Taura T, Baba T, Akiyama Y, Ito K. 1993. Determinants of the quantity of the stable SecY complex in the Escherichia coli cell. J Bacteriol 175:7771–7775. [PubMed]
313. Kihara A, Akiyama Y, Ito K. 1995. FtsH is required for proteolytic elimination of uncomplexed forms of SecY, an essential protein translocase subunit. Proc Natl Acad Sci USA 92:4532–4536. [PubMed]
314. Kato Y, Nishiyama K, Tokuda H. 2003. Depletion of SecDF-YajC causes a decrease in the level of SecG: implication for their functional interaction. FEBS Lett 550:114–118.
315. von Heijne G. 1983. Patterns of amino acids near signal-sequence cleavage sites. Eur J Biochem 133:17–21. [PubMed]
316. von Heijne G. 1990. The signal peptide. J Membr Biol 115:195–201. [PubMed]
317. Dierstein R, Wickner W. 1986. Requirements for substrate recognition by bacterial leader peptidase. EMBO J 5:427–431. [PubMed]
318. Zwizinski C, Wickner W. 1980. Purification and characterization of leader (signal) peptidase from Escherichia coli. J Biol Chem 255:7973–7977. [PubMed]
319. Date T, Wickner W. 1981. Isolation of the Escherichia coli leader peptidase gene and effects of leader peptidase overproduction in vivo. Proc Natl Acad Sci USA 78:6106–6110. [PubMed]
320. Zimmermann R, Watts C, Wickner W. 1982. The biosynthesis of membrane-bound M13 coat protein. Energetics and assembly intermediates. J Biol Chem 257:6529–6536. [PubMed]
321. Wolfe PB, Wickner W, Goodman JM. 1983. Sequence of the leader peptidase gene of Escherichia coli and the orientation of leader peptidase in the bacterial envelope. J Biol Chem 258:12073–12080. [PubMed]
322. Dalbey RE, Wickner W. 1985. Leader peptidase catalyzes the release of exported proteins from the outer surface of the Escherichia coli plasma membrane. J Biol Chem 260:15925–15931. [PubMed]
323. Wolfe PB, Silver P, Wickner W. 1982. The isolation of homogeneous leader peptidase from a strain of Escherichia coli which overproduces the enzyme. J Biol Chem 257:7898–7902. [PubMed]
324. Tschantz WR, Sung M, Delgado-Partin VM, Dalbey RE. 1993. A serine and a lysine residue implicated in the catalytic mechanism of the Escherichia coli leader peptidase. J Biol Chem 268:27349–27354. [PubMed]
325. Paetzel M. 2014. Structure and mechanism of Escherichia coli type I signal peptidase. Biochim Biophys Acta 1843:1497–1508. [PubMed]
326. Sung M, Dalbey RE. 1992. Identification of potential active-site residues in the Escherichia coli leader peptidase. J Biol Chem 267:13154–13159. [PubMed]
327. Black MT. 1993. Evidence that the catalytic activity of prokaryote leader peptidase depends upon the operation of a serine-lysine catalytic dyad. J Bacteriol 175:4957–4961. [PubMed]
328. Paetzel M, Strynadka NC, Tschantz WR, Casareno R, Bullinger PR, Dalbey RE. 1997. Use of site-directed chemical modification to study an essential lysine in Escherichia coli leader peptidase. J Biol Chem 272:9994–10003. [PubMed]
329. Klenotic PA, Carlos JL, Samuelson JC, Schuenemann TA, Tschantz WR, Paetzel M, Strynadka NC, Dalbey RE. 2000. The role of the conserved box E residues in the active site of the Escherichia coli type I signal peptidase. J Biol Chem 275:6490–6498. [PubMed]
330. Lüke I, Handford JI, Palmer T, Sargent F. 2009. Proteolytic processing of Escherichia coli twin-arginine signal peptides by LepB. Arch Microbiol 191:919–925. [PubMed]
331. Yamagata H, Taguchi N, Daishima K, Mizushima S. 1983. Genetic characterization of a gene for prolipoprotein signal peptidase in Escherichia coli. Mol Gen Genet 192:10–14. [PubMed]
332. Tokunaga M, Tokunaga H, Wu HC. 1982. Post-translational modification and processing of Escherichia coli prolipoprotein in vitro. Proc Natl Acad Sci USA 79:2255–2259. [PubMed]
333. Sankaran K, Wu HC. 1994. Lipid modification of bacterial prolipoprotein. Transfer of diacylglyceryl moiety from phosphatidylglycerol. J Biol Chem 269:19701–19706. [PubMed]
334. Miyadai H, Tanaka-Masuda K, Matsuyama S, Tokuda H. 2004. Effects of lipoprotein overproduction on the induction of DegP (HtrA) involved in quality control in the Escherichia coli periplasm. J Biol Chem 279:39807–39813. [PubMed]
335. Novak P, Dev IK. 1988. Degradation of a signal peptide by protease IV and oligopeptidase A. J Bacteriol 170:5067–5075. [PubMed]
336. Kim AC, Oliver DC, Paetzel M. 2008. Crystal structure of a bacterial signal Peptide peptidase. J Mol Biol 376:352–366. [PubMed]
337. Saito A, Hizukuri Y, Matsuo E, Chiba S, Mori H, Nishimura O, Ito K, Akiyama Y. 2011. Post-liberation cleavage of signal peptides is catalyzed by the site-2 protease (S2P) in bacteria. Proc Natl Acad Sci USA 108:13740–13745. [PubMed]
338. Inaba K, Suzuki M, Maegawa K, Akiyama S, Ito K, Akiyama Y. 2008. A pair of circularly permutated PDZ domains control RseP, the S2P family intramembrane protease of Escherichia coli. J Biol Chem 283:35042–35052. [PubMed]
339. de Vrije T, de Swart RL, Dowhan W, Tommassen J, de Kruijff B. 1988. Phosphatidylglycerol is involved in protein translocation across Escherichia coli inner membranes. Nature 334:173–175. [PubMed]
340. Kusters R, Dowhan W, de Kruijff B. 1991. Negatively charged phospholipids restore prePhoE translocation across phosphatidylglycerol-depleted Escherichia coli inner membranes. J Biol Chem 266:8659–8662. [PubMed]
341. Dowhan W. 2013. A retrospective: use of Escherichia coli as a vehicle to study phospholipid synthesis and function. Biochim Biophys Acta 1831:471–494. [PubMed]
342. Heacock PN, Dowhan W. 1989. Alteration of the phospholipid composition of Escherichia coli through genetic manipulation. J Biol Chem 264:14972–14977. [PubMed]
343. Kikuchi S, Shibuya I, Matsumoto K. 2000. Viability of an Escherichia coli pgsA null mutant lacking detectable phosphatidylglycerol and cardiolipin. J Bacteriol 182:371–376. [PubMed]
344. Breukink E, Demel RA, de Korte-Kool G, de Kruijff B. 1992. SecA insertion into phospholipids is stimulated by negatively charged lipids and inhibited by ATP: a monolayer study. Biochemistry 31:1119–1124. [PubMed]
345. Hsieh YH, Zhang H, Lin BR, Cui N, Na B, Yang H, Jiang C, Sui SF, Tai PC. 2011. SecA alone can promote protein translocation and ion channel activity: SecYEG increases efficiency and signal peptide specificity. J Biol Chem 286:44702–44709. [PubMed]
346. Hsieh YH, Zhang H, Wang H, Yang H, Jiang C, Sui SF, Tai PC. 2013. Reconstitution of functionally efficient SecA-dependent protein-conducting channels: transformation of low-affinity SecA-liposome channels to high-affinity SecA-SecYEG-SecDF·YajC channels. Biochem Biophys Res Commun 431:388–392. [PubMed]
347. Gold VA, Robson A, Bao H, Romantsov T, Duong F, Collinson I. 2010. The action of cardiolipin on the bacterial translocon. Proc Natl Acad Sci USA 107:10044–10049. [PubMed]
348. Prabudiansyah I, Kusters I, Caforio A, Driessen AJM. 2015. Characterization of the annular lipid shell of the Sec translocon. Biochim Biophys Acta 1848:2050–2056. [PubMed]
349. van den Brink-van der Laan E, Killian JA, de Kruijff B. 2004. Nonbilayer lipids affect peripheral and integral membrane proteins via changes in the lateral pressure profile. Biochim Biophys Acta 1666:275–288. [PubMed]
350. van der Does C, Swaving J, van Klompenburg W, Driessen AJM. 2000. Non-bilayer lipids stimulate the activity of the reconstituted bacterial protein translocase. J Biol Chem 275:2472–2478. [PubMed]
351. du Plessis DJ, Berrelkamp G, Nouwen N, Driessen AJ. 2009. The lateral gate of SecYEG opens during protein translocation. J Biol Chem 284:15805–15814. [PubMed]
352. Frauenfeld J, Gumbart J, Sluis EO, Funes S, Gartmann M, Beatrix B, Mielke T, Berninghausen O, Becker T, Schulten K, Beckmann R. 2011. Cryo-EM structure of the ribosome-SecYE complex in the membrane environment. Nat Struct Mol Biol 18:614–621. [PubMed]
353. Lycklama a Nijeholt JA, Wu ZC, Driessen AJ. 2011. Conformational dynamics of the plug domain of the SecYEG protein-conducting channel. J Biol Chem 286:43881–43890. [PubMed]
354. Ahn T, Kim H. 1998. Effects of nonlamellar-prone lipids on the ATPase activity of SecA bound to model membranes. J Biol Chem 273:21692–21698. [PubMed]
355. van Klompenburg W, Paetzel M, de Jong JM, Dalbey RE, Demel RA, von Heijne G, de Kruijff B. 1998. Phosphatidylethanolamine mediates insertion of the catalytic domain of leader peptidase in membranes. FEBS Lett 431:75–79 .
356. van den Brink-van der Laan E, Dalbey RE, Demel RA, Killian JA, de Kruijff B. 2001. Effect of nonbilayer lipids on membrane binding and insertion of the catalytic domain of leader peptidase. Biochemistry 40:9677–9684. [PubMed]
357. Wang Y, Bruckner R, Stein RL. 2004. Regulation of signal peptidase by phospholipids in membrane: characterization of phospholipid bilayer incorporated Escherichia coli signal peptidase. Biochemistry 43:265–270. [PubMed]
358. McKnight CJ, Briggs MS, Gierasch LM. 1989. Functional and nonfunctional LamB signal sequences can be distinguished by their biophysical properties. J Biol Chem 264:17293–17297. [PubMed]
359. Jones JD, McKnight CJ, Gierasch LM. 1990. Biophysical studies of signal peptides: implications for signal sequence functions and the involvement of lipid in protein export. J Bioenerg Biomembr 22:213–232. [PubMed]
360. Killian JA, Keller RC, Struyvé M, de Kroon AI, Tommassen J, de Kruijff B. 1990. Tryptophan fluorescence study on the interaction of the signal peptide of the Escherichia coli outer membrane protein PhoE with model membranes. Biochemistry 29:8131–8137. [PubMed]
361. Hoyt DW, Gierasch LM. 1991. A peptide corresponding to an export-defective mutant OmpA signal sequence with asparagine in the hydrophobic core is unable to insert into model membranes. J Biol Chem 266:14406–14412. [PubMed]
362. Hoyt DW, Gierasch LM. 1991. Hydrophobic content and lipid interactions of wild-type and mutant OmpA signal peptides correlate with their in vivo function. Biochemistry 30:10155–10163.
363. Keller RC, Killian JA, de Kruijff B. 1992. Anionic phospholipids are essential for alpha-helix formation of the signal peptide of prePhoE upon interaction with phospholipid vesicles. Biochemistry 31:1672–1677. [PubMed]
364. Ahn T, Oh DB, Kim H, Park C. 2002. The phase property of membrane phospholipids is affected by the functionality of signal peptides from the Escherichia coli ribose-binding protein. J Biol Chem 277:26157–26162. [PubMed]
365. Kendall DA, Kaiser ET. 1988. A functional decaisoleucine-containing signal sequence. Construction by cassette mutagenesis. J Biol Chem 263:7261–7265. [PubMed]
366. Killian JA, de Jong AM, Bijvelt J, Verkleij AJ, de Kruijff B. 1990. Induction of non-bilayer lipid structures by functional signal peptides. EMBO J 9:815–819. [PubMed]
367. Graves R. 1975. Collected Poems, 1975. Cassell, London.
368. Denks K, Vogt A, Sachelaru I, Petriman N-A, Kudva R, Koch H-G. 2014. The Sec translocon mediated protein transport in prokaryotes and eukaryotes. Mol Membr Biol 31:58–84. [PubMed]
369. Lycklama A, Nijeholt JA, Driessen AJM. 2012. The bacterial Sec-translocase: structure and mechanism. Philos Trans R Soc Lond B Biol Sci 367:1016–1028. [PubMed]
370. Chatzi KE, Sardis MF, Economou A, Karamanou S. 2014. SecA-mediated targeting and translocation of secretory proteins. Biochim Biophys Acta 1843:1466–1474. [PubMed]
371. Palmer T, Berks BC. 2012. The twin-arginine translocation (Tat) protein export pathway. Nat Rev Microbiol 10:483–496. [PubMed]
372. Patel R, Smith SM, Robinson C. 2014. Protein transport by the bacterial Tat pathway. Biochim Biophys Acta 1843:1620–1628. [PubMed]
373. Saraogi I, Shan SO. 2014. Co-translational protein targeting to the bacterial membrane. Biochim Biophys Acta 1843:1433–1441. [PubMed]
374. Zhang X, Shan SO. 2014. Fidelity of cotranslational protein targeting by the signal recognition particle. Annu Rev Biophys 43:381–408. [PubMed]
375. Dalbey RE, Kuhn A, Zhu L, Kiefer D. 2014. The membrane insertase YidC. Biochim Biophys Acta 1843:1489–1496. [PubMed]
376. Hennon SW, Soman R, Zhu L, Dalbey RE. 2015. YidC/Alb3/Oxa1 Family of Insertases. J Biol Chem 290:14866–14874. [PubMed]
377. Nivaskumar M, Francetic O. 2014. Type II secretion system: a magic beanstalk or a protein escalator. Biochim Biophys Acta 1843:1568–1577. [PubMed]
378. van Ulsen P, Rahman S, Jong WS, Daleke-Schermerhorn MH, Luirink J. 2014. Type V secretion: from biogenesis to biotechnology. Biochim Biophys Acta 1843:1592–1611. [PubMed]
379. Ricci DP, Silhavy TJ. 2012. The Bam machine: a molecular cooper. Biochim Biophys Acta 1818:1067–1084. [PubMed]
380. Okuda S, Tokuda H. 2011. Lipoprotein sorting in bacteria. Annu Rev Microbiol 65:239–259. [PubMed]
381. Konovalova A, Silhavy TJ. 2015. Outer membrane lipoprotein biogenesis: lol is not the end. Philos Trans R Soc Lond B Biol Sci 370:20150030. doi:10.1098/rstb.2015.0030
382. Thomas S, Holland IB, Schmitt L. 2014. The Type 1 secretion pathway - the hemolysin system and beyond. Biochim Biophys Acta 1843:1629–1641. [PubMed]
383. Christie PJ, Whitaker N, González-Rivera C. 2014. Mechanism and structure of the bacterial type IV secretion systems. Biochim Biophys Acta 1843:1578–1591. [PubMed]
384. Zoued A, Brunet YR, Durand E, Aschtgen MS, Logger L, Douzi B, Journet L, Cambillau C, Cascales E. 2014. Architecture and assembly of the Type VI secretion system. Biochim Biophys Acta 1843:1664–1673. [PubMed]
385. Burkinshaw BJ, Strynadka NC. 2014. Assembly and structure of the T3SS. Biochim Biophys Acta 1843:1649–1663. [PubMed]
386. Oliver DB, Beckwith J. 1981. E. coli mutant pleiotropically defective in the export of secreted proteins. Cell 25:765–772.
387. Kawasaki H, Matsuyama S, Sasaki S, Akita M, Mizushima S. 1989. SecA protein is directly involved in protein secretion in Escherichia coli. FEBS Lett 242:431–434.
388. Sullivan NF, Donachie WD. 1984. Transcriptional organization within an Escherichia coli cell division gene cluster: direction of transcription of the cell separation gene envA. J Bacteriol 160:724–732. [PubMed]
389. Garza-Sánchez F, Janssen BD, Hayes CS. 2006. Prolyl-tRNA(Pro) in the A-site of SecM-arrested ribosomes inhibits the recruitment of transfer-messenger RNA. J Biol Chem 281:34258–34268. [PubMed]
390. Ito K. 1984. Identification of the secY (prlA) gene product involved in protein export in Escherichia coli. Mol Gen Genet 197:204–208. [PubMed]
391. Shiba K, Ito K, Yura T, Cerretti DP. 1984. A defined mutation in the protein export gene within the spc ribosomal protein operon of Escherichia coli: isolation and characterization of a new temperature-sensitive secY mutant. EMBO J 3:631–635. [PubMed]
392. Riggs PD, Derman AI, Beckwith J. 1988. A mutation affecting the regulation of a secA-lacZ fusion defines a new sec gene. Genetics 118:571–579. [PubMed]
393. Hanada M, Nishiyama KI, Mizushima S, Tokuda H. 1994. Reconstitution of an efficient protein translocation machinery comprising SecA and the three membrane proteins, SecY, SecE, and SecG (p12). J Biol Chem 269:23625–23631. [PubMed]
394. Fang J, Wei Y. 2011. Expression, purification and characterization of the Escherichia coli integral membrane protein YajC. Protein Pept Lett 18:601–608. [PubMed]
395. Samuelson JC, Chen M, Jiang F, Möller I, Wiedmann M, Kuhn A, Phillips GJ, Dalbey RE. 2000. YidC mediates membrane protein insertion in bacteria. Nature 406:637–641. [PubMed]
396. Martinez Molina D, Lundbäck AK, Niegowski D, Eshaghi S. 2008. Expression and purification of the recombinant membrane protein YidC: a case study for increased stability and solubility. Protein Expr Purif 62:49–52. [PubMed]
397. Kim DM, Zheng H, Huang YJ, Montelione GT, Hunt JF. 2013. ATPase active-site electrostatic interactions control the global conformation of the 100 kDa SecA translocase. J Am Chem Soc 135:2999–3010. [PubMed]
398. Nithianantham S, Shilton BH. 2008. Analysis of the isolated SecA DEAD motor suggests a mechanism for chemical-mechanical coupling. J Mol Biol 383:380–389. [PubMed]
399. Swanson S, Ioerger TR, Rigel NW, Miller BK, Braunstein M, Sacchettini JC. 2015. Structural similarities and differences between two functionally distinct seca proteins, Mycobacterium tuberculosis SecA1 and SecA2. J Bacteriol 198:720–730. [PubMed]
400. Mitra K, Schaffitzel C, Shaikh T, Tama F, Jenni S, Brooks CL III, Ban N, Frank J. 2005. Structure of the E. coli protein-conducting channel bound to a translating ribosome. Nature 438:318–324. [PubMed]
401. Ménétret JF, Schaletzky J, Clemons WM Jr, Osborne AR, Skånland SS, Denison C, Gygi SP, Kirkpatrick DS, Park E, Ludtke SJ, Rapoport TA, Akey CW. 2007. Ribosome binding of a single copy of the SecY complex: implications for protein translocation. Mol Cell 28:1083–1092. [PubMed]
402. Gumbart J, Trabuco LG, Schreiner E, Villa E, Schulten K. 2009. Regulation of the protein-conducting channel by a bound ribosome. Structure 17:1453–1464. [PubMed]
403. Wickles S, Singharoy A, Andreani J, Seemayer S, Bischoff L, Berninghausen O, Soeding J, Schulten K, van der Sluis EO, Beckmann R. 2014. A structural model of the active ribosome-bound membrane protein insertase YidC. eLife 3:e03035. doi:10.7554/eLife.03035
404. Kumazaki K, Kishimoto T, Furukawa A, Mori H, Tanaka Y, Dohmae N, Ishitani R, Tsukazaki T, Nureki O. 2014. Crystal structure of Escherichia coli YidC, a membrane protein chaperone and insertase. Sci Rep 4:7299. doi:10.1038/srep07299 [PubMed]
405. Oliver DC, Paetzel M. 2008. Crystal structure of the major periplasmic domain of the bacterial membrane protein assembly facilitator YidC. J Biol Chem 283:5208–5216. [PubMed]
406. Ravaud S, Stjepanovic G, Wild K, Sinning I. 2008. The crystal structure of the periplasmic domain of the Escherichia coli membrane protein insertase YidC contains a substrate binding cleft. J Biol Chem 283:9350–9358. [PubMed]
407. Paetzel M, Dalbey RE, Strynadka NC. 1998. Crystal structure of a bacterial signal peptidase in complex with a beta-lactam inhibitor. Nature 396:186–190. [PubMed]
408. Paetzel M, Dalbey RE, Strynadka NC. 2002. Crystal structure of a bacterial signal peptidase apoenzyme: implications for signal peptide binding and the Ser-Lys dyad mechanism. J Biol Chem 277:9512–9519. [PubMed]
409. Paetzel M, Goodall JJ, Kania M, Dalbey RE, Page MG. 2004. Crystallographic and biophysical analysis of a bacterial signal peptidase in complex with a lipopeptide-based inhibitor. J Biol Chem 279:30781–30790. [PubMed]
410. Luo C, Roussel P, Dreier J, Page MG, Paetzel M. 2009. Crystallographic analysis of bacterial signal peptidase in ternary complex with arylomycin A2 and a beta-sultam inhibitor. Biochemistry 48:8976–8984. [PubMed]
411. Liu J, Luo C, Smith PA, Chin JK, Page MG, Paetzel M, Romesberg FE. 2011. Synthesis and characterization of the arylomycin lipoglycopeptide antibiotics and the crystallographic analysis of their complex with signal peptidase. J Am Chem Soc 133:17869–17877. [PubMed]
412. Matsuyama S, Mizushima S. 1995. Biochemical analyses of components comprising the protein translocation machinery of Escherichia coli, p 61–84. In Tartakoff AM, Dalbey RE (ed), Advances in Cell and Molecular Biology of Membranes and Organelles: Protein Export and Membrane Biogenesis, vol 4. JAI Press Ltd, Hampton Hill, Middlesex, England.
413. Urbanus ML, Fröderberg L, Drew D, Björk P, de Gier J-WL, Brunner J, Oudega B, Luirink J. 2002. Targeting, insertion, and localization of Escherichia coli YidC. J Biol Chem 277:12718–12723. [PubMed]
414. van Klompenburg W, Whitley P, Diemel R, von Heijne G, de Kruijff B. 1995. A quantitative assay to determine the amount of signal peptidase I in E. coli and the orientation of membrane vesicles. Mol Membr Biol 12:349–353. [PubMed]
415. Milo R, Phillips R. 2016. Cell Biology by the Numbers. Garland Science, New York, NY.
416. Kusters R, de Vrije T, Breukink E, de Kruijff B. 1989. SecB protein stabilizes a translocation-competent state of purified prePhoE protein. J Biol Chem 264:20827–20830. [PubMed]
417. Powers EL, Randall LL. 1995. Export of periplasmic galactose-binding protein in Escherichia coli depends on the chaperone SecB. J Bacteriol 177:1906–1907. [PubMed]
418. Ishihama Y, Schmidt T, Rappsilber J, Mann M, Hartl FU, Kerner MJ, Frishman D. 2008. Protein abundance profiling of the Escherichia coli cytosol. BMC Genomics 9:102. [PubMed]
419. Findik BT, Randall LL. 2017. Determination of the intracellular concentration of the export chaperone SecB in Escherichia coli. PLosOne 8:e0183231. doi.org/10.1371/journal.pone.0183231 [PubMed]
420. Schmidt A, Kochanowski K, Vedelaar S, Ahrne E, Volkmer B, Callipo L, Knoops K, Bauer M, Aebersold R, Heinemann M. 2016. The quantitative and condition-dependent Escherichia coli proteome. Nat Biotechnol 34:104–110. [PubMed]

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In , proteins found in the periplasm or the outer membrane are exported from the cytoplasm by the general secretory, Sec, system before they acquire stably folded structure. This dynamic process involves intricate interactions among cytoplasmic and membrane proteins, both peripheral and integral, as well as lipids. , both ATP hydrolysis and proton motive force are required. Here, we review the Sec system from the inception of the field through early 2016, including biochemical, genetic, and structural data.

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Image of Figure 1
Figure 1

The structures are shown in ribbon representation of SecYEG in complex with SecA from PDB 3DIN; SecDF from PDB 3AQO; YidC from PDB 1B12; signal peptide peptidase soluble domain PDB 3BF0; SecA dimer from PDB 1M6N; SecA monomer from 1TF5; SecB from PDB 1QYN.

Citation: Crane J, Randall L. 2017. The Sec System: Protein Export in , EcoSal Plus 2017; doi:10.1128/ecosalplus.ESP-0002-2017
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Figure 2

SecB is a tetramer organized as a dimer of dimers. (a) and (c) show the two protomers that make eight-stranded β sheets on the flat sides of SecB. (b) and (d) are related to (a) and (c) by 90° rotation to show the interface of the dimer of dimers. Each protomer is shown as a different color. PDB 1QYN.

Citation: Crane J, Randall L. 2017. The Sec System: Protein Export in , EcoSal Plus 2017; doi:10.1128/ecosalplus.ESP-0002-2017
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Figure 3

Site-directed spin labeling and electron paramagnetic resonance spectroscopy were used to map the contact sites between SecB and polypeptide ligands. The sites of contact are shown in green. Residues that showed no contact are shown in gray, and residues not tested are shown in yellow. (a) Flat eight-stranded β-sheet on the side of the tetramer. (b) is related to (a) by a 90° rotation around the vertical axis to show the channel at the interface between the dimers. (c) The end view of the tetramer shows the depth of the channel. The structure was generated by threading the sequence through the structure (PDB 1FX3) which has more C-terminal residues resolved than does the structure. Reprinted from reference 70 , with permission.

Citation: Crane J, Randall L. 2017. The Sec System: Protein Export in , EcoSal Plus 2017; doi:10.1128/ecosalplus.ESP-0002-2017
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Figure 4

(a) The sequence is SecA with the domains colored as in the structures. See text for domain abbreviations. (b) SecA from in CPK representation, PDB 2FSF with the PBD modeled based on SecA, PDB ITF5, by A. Economou. (c) Ribbon representation of SecA shown in (b). (d) to (g) Ribbon representation of SecA from the following species: (d) , PDB 2IPC; (e) , PDB 1NL3; (f) , PDB 1M6N; and (g) , PDB 3JUX.

Citation: Crane J, Randall L. 2017. The Sec System: Protein Export in , EcoSal Plus 2017; doi:10.1128/ecosalplus.ESP-0002-2017
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Figure 5

The closed conformation of SecA (PDB 1M6N) is shown as the gray ribbon. The open conformation of SecA (PDB 1TF5) is shown in ribbon representation with the domains colored as in Fig. 4 . The Protein Binding Domain (pink) is the only domain that has moved.

Citation: Crane J, Randall L. 2017. The Sec System: Protein Export in , EcoSal Plus 2017; doi:10.1128/ecosalplus.ESP-0002-2017
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Image of Figure 6
Figure 6

Dimeric structures of SecA with the domains colored as in Fig. 4 . The SecA species are from (a) PDB 1M6N, (b) PDB 2IPC, (c) PDB 1NL3, (d) PDB 2FSF, (e) PDB 2IB; the three-stranded β-sheet that forms the interface is circled and enlarged in (f).

Citation: Crane J, Randall L. 2017. The Sec System: Protein Export in , EcoSal Plus 2017; doi:10.1128/ecosalplus.ESP-0002-2017
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Figure 7

The structure of SecYEβ (PDB 1RHZ) is shown as an example of the common structure of the SecYE core. SecY is shown as the orange ribbon, SecE as the green ribbon, and Secβ (SecG in ) as purple. The view in (a) is in the plane of the membrane with the cytoplasmic face at the top and the periplasmic face at the bottom. The view in (b) results from a 90° rotation toward the viewer to show the channel in the translocon from the cytoplasmic face. The plug can be seen in the middle of the channel at the periplasmic side.

Citation: Crane J, Randall L. 2017. The Sec System: Protein Export in , EcoSal Plus 2017; doi:10.1128/ecosalplus.ESP-0002-2017
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Image of Figure 8
Figure 8

Ribbon representation of SecA from with the PBD in different positions. The Linker Helix is shown in green and the NBD2 in brown to serve as references for movement of the PBD, shown in magenta. The reminder of the SecA is represented in gray. The SecY loop between TM6 and TM7 which inserts into SecA is shown in cyan in (c). (a) SecA in solution, PDB 3JUX; (b) SecA in solution with ADP bound, PDB 4YS0; and (c) SecA with ADP and BeFx bound in complex with SecY, PDB 3DIN.

Citation: Crane J, Randall L. 2017. The Sec System: Protein Export in , EcoSal Plus 2017; doi:10.1128/ecosalplus.ESP-0002-2017
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Figure 9

SecG has two transmembrane domains represented by orange and a segment connecting the two membrane domains represented by blue. The N and C termini lie on the same side of the membrane. The left-hand image represents SecG in the idle state. During protein translocation SecG inverts as shown on the right-hand side. The open arrows indicate sites of protease cleavage. The region at the C terminus recognized by anti-SecG antibody is indicated.

Citation: Crane J, Randall L. 2017. The Sec System: Protein Export in , EcoSal Plus 2017; doi:10.1128/ecosalplus.ESP-0002-2017
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Image of Figure 10
Figure 10

The structure of SecDF, which is encoded as a single polypeptide chain, is colored to represent the individual SecD and SecF polypeptides found in . Transmembrane helices 1 to 6 (blue) represent SecD. The periplasmic P1 domain between TM1 and TM2 is shown at the top of the figure. The head and the base subdomains are indicated. Transmembrane helices 7 and 8 represent SecF.

Citation: Crane J, Randall L. 2017. The Sec System: Protein Export in , EcoSal Plus 2017; doi:10.1128/ecosalplus.ESP-0002-2017
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Image of Figure 11
Figure 11

The P1 domain of SecDF, shown extending into the periplasm comprises two subdomains: a P1 head (orange) and P1 base (blue). The protein was crystallized in the F form (left-hand side) with the P1 domain positioned so that the head is bent toward the membrane. The I form shows the head directly above the base. This structure is a model built from superimposing the base subdomain of the isolated P1 structure onto that of the full-length SecDF. Reprinted from reference 233 , with permission.

Citation: Crane J, Randall L. 2017. The Sec System: Protein Export in , EcoSal Plus 2017; doi:10.1128/ecosalplus.ESP-0002-2017
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Table 1

Systems of protein export

Citation: Crane J, Randall L. 2017. The Sec System: Protein Export in , EcoSal Plus 2017; doi:10.1128/ecosalplus.ESP-0002-2017
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Table 2

Proteins of the Sec system

Citation: Crane J, Randall L. 2017. The Sec System: Protein Export in , EcoSal Plus 2017; doi:10.1128/ecosalplus.ESP-0002-2017
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Table 3

Structures of the proteins in the Sec system

Citation: Crane J, Randall L. 2017. The Sec System: Protein Export in , EcoSal Plus 2017; doi:10.1128/ecosalplus.ESP-0002-2017
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Table 4

Level of the Sec proteins in

Citation: Crane J, Randall L. 2017. The Sec System: Protein Export in , EcoSal Plus 2017; doi:10.1128/ecosalplus.ESP-0002-2017
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Table 5

Proteins that utilize SecB

Citation: Crane J, Randall L. 2017. The Sec System: Protein Export in , EcoSal Plus 2017; doi:10.1128/ecosalplus.ESP-0002-2017

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