Chapter 3 : Regulation by Alternative Sigma Factors

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This chapter summarizes the alternative sigma factors of the two model organisms ( and ), describes the types of regulatory pathways that have evolved to control σ activity, and presents a glimpse at some recently discovered variations on these already established themes. In addition, many stress-induced proteins were initially identified using proteomics and were named for the inducing stress(es). Examples include general stress proteins (GSP) and heat shock proteins (HSP). Regulation of σ proteolysis plays a major role in controlling activation of this stress response by starvation for diverse nutrients and several other stresses. Although the full implications of the complex regulatory architecture are not yet clear, a number of advantages are apparent. First, the branched pathway allows for integration of two distinct classes of signals and, within each signaling pathway, there are likely multiple regulatory targets thereby enabling a further diversity of inputs. Second, the use of reversible protein modifications (phosphorylation/ dephosphorylation) enables a rapid response to changing conditions and also enables the system to be rapidly shut off once homeostatic conditions are restored. Third, the use of reversible protein modifications to regulate activity may ultimately be more energy efficient than those systems that rely instead on destruction of an anti-σ with the consequent need for new protein synthesis to reset the system. Sporulation in was the first process unambiguously shown to rely on alternative s factors for its execution and thus holds a special place in the historical development of σ factor biology.

Citation: Helmann J. 2011. Regulation by Alternative Sigma Factors, p 31-43. In Storz G, Hengge R (ed), Bacterial Stress Responses, Second Edition. ASM Press, Washington, DC. doi: 10.1128/9781555816841.ch3
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Image of Figure 1.
Figure 1.

Overview of bacterial σ factor structure-function relationships. (A) The interaction of a generic σ family protein with a promoter sequence is illustrated. Structural studies reveal three conserved domains in bacterial σ factors (σ2, σ3, and σ4) corresponding roughly to regions of sequence conservation. Conserved motifs in region 4.2 (within a classical helix-turn-helix unit) recognize the –35 element while –10 region recognition and melting is mediated by residues from regions 2.3 and 2.4. Region 3 contributes to the recognition of sequences adjacent to the –10 element in “extended –10” promoters. Bacterial σ factors are divided into distinct structural groups based on the presence or absence of conserved sequence regions 1 though 4. Note that ECF σ factors have only regions 2 and 4 and, in the case of the bipartite σ YvrI/YvrHa, these two functions are in separate polypeptides. (B) A schematic illustrating the relative position of the three conserved σ domains with the holoenzyme complex. Major roles of each region are illustrated including protein regions implicated in core-binding, –35 and –10 element recognition and promoter melting, and contacts with regulatory proteins (anti-σ factors) and DNA-binding transcription activators.

Citation: Helmann J. 2011. Regulation by Alternative Sigma Factors, p 31-43. In Storz G, Hengge R (ed), Bacterial Stress Responses, Second Edition. ASM Press, Washington, DC. doi: 10.1128/9781555816841.ch3
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Image of Figure 2.
Figure 2.

Modes of regulation for σ factors. A generic hypothetical σ factor (σ) is shown together with a schematic illustration of the various modes of regulating σ factor activity. Activity can be regulated at the following levels: transcription (e.g., by positive feedback regulation), translation, protein processing (conversion of pro-σ to functional protein; not illustrated), protein activity (by anti-σ RsiQ), or by controlled proteolysis of either the σ or anti-σ. As illustrated here, expression of the operon by σ generates both positive feedback loops (autoregulation of σ) and a negative feedback loop (RsiQ). This type of regulation is common amongst ECF σ factors. In other cases, other members of the σ regulon may act as either positive or negative feedback regulators.

Citation: Helmann J. 2011. Regulation by Alternative Sigma Factors, p 31-43. In Storz G, Hengge R (ed), Bacterial Stress Responses, Second Edition. ASM Press, Washington, DC. doi: 10.1128/9781555816841.ch3
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Figure 3.

Mechanisms for controlling the activity of anti-σ factors. Anti-σ factors can be regulated by: (i) proteolytic destruction (e.g., RIP of RseA to release σ); (ii) protein-protein interactions such as transmembrane signaling as illustrated for the ferric-citrate mediated induction of the σ regulon mediated by FecA and FecR; (iii) secretion from the cell as in the example of FlgM which is exported through the completed hook-basal body (HBB); or (iv) sequestration by an anti-anti-σ (e.g., partnerswitching mechanism as illustrated for σ). See text for details.

Citation: Helmann J. 2011. Regulation by Alternative Sigma Factors, p 31-43. In Storz G, Hengge R (ed), Bacterial Stress Responses, Second Edition. ASM Press, Washington, DC. doi: 10.1128/9781555816841.ch3
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1. Ades, S. E. 2004. Control of the alternative sigma factor sigmaE in Escherichia coli. Curr. Opin. Microbiol. 7: 157162.
2. Ades, S. E. 2008. Regulation by destruction: design of the sigmaE envelope stress response. Curr. Opin. Microbiol. 11: 535540.
3. Ades,, S. E.,, L. E. Connolly,, B. M. Alba, and, C. A. Gross. 1999. The Escherichia coli sigma(E)-dependent extracytoplasmic stress response is controlled by the regulated proteolysis of an anti-sigma factor. Genes Dev. 13: 24492461.
4. Alba, B. M., and, C. A. Gross. 2004. Regulation of the Escherichia coli sigma-dependent envelope stress response. Mol. Microbiol. 52: 613619.
5. Alba,, B. M.,, J. A. Leeds,, C. Onufryk,, C. Z. Lu, and, C. A. Gross. 2002. DegS and YaeL participate sequentially in the cleavage of RseA to activate the sigma(E)-dependent extracytoplasmic stress response. Genes Dev. 16: 21562168.
6. Aldridge, P., and, K. T. Hughes. 2002. Regulation of flagellar assembly. Curr. Opin. Microbiol. 5: 160165.
7. Alper, S.,, L. Duncan, and, R. Losick. 1994. An adenosine nucleotide switch controlling the activity of a cell type-specific transcription factor in B. Subtilis. Cell 77: 195205.
8. Barembruch, C., and, R. Hengge. 2007. Cellular levels and activity of the flagellar sigma factor FliA of Escherichia coli are controlled by FlgM-modulated proteolysis. Mol. Microbiol. 65: 7689.
9. Barnard, A.,, A. Wolfe, and, S. Busby. 2004. Regulation at complex bacterial promoters: how bacteria use different promoter organizations to produce different regulatory outcomes. Curr. Opin. Microbiol. 7: 102108.
10. Becker, G.,, E. Klauck, and, R. Hengge-Aronis. 1999. Regulation of RpoS proteolysis in Escherichia coli: the response regulator RssB is a recognition factor that interacts with the turnover element in RpoS. Proc. Natl. Acad. Sci. USA 96: 64396444.
11. Borukhov, S., and, E. Nudler. 2003. RNA polymerase holoenzyme: structure, function and biological implications. Curr. Opin. Microbiol. 6: 93100.
12. Borukhov, S., and, K. Severinov. 2002. Role of the RNA polymerase sigma subunit in transcription initiation. Res. Microbiol. 153: 557562.
13. Bougdour,, A., C. Cunning,, P. J. Baptiste,, T. Elliott, and, S. Gottesman. 2008. Multiple pathways for regulation of sigmaS (RpoS) stability in Escherichia coli via the action of multiple anti-adaptors. Mol. Microbiol. 68: 298313.
14. Bougdour, A., and, S. Gottesman. 2007. ppGpp regulation of RpoS degradation via anti-adaptor protein IraP. Proc. Natl. Acad. Sci. USA 104: 1289612901.
15. Braun, V., and, S. Mahren. 2005. Transmembrane transcriptional control (surface signalling) of the Escherichia coli Fec type. FEMS Microbiol. Rev. 29: 673684.
16. Braun, V.,, S. Mahren, and, M. Ogierman. 2003. Regulation of the FecI-type ECF sigma factor by transmembrane signalling. Curr. Opin. Microbiol. 6: 173180.
17. Brooks, B. E., and, S. K. Buchanan. 2008. Signaling mechanisms for activation of extracytoplasmic function (ECF) sigma factors. Biochim. Biophys. Acta. 1778: 19301945.
18. Browning, D. F., and, S. J. Busby. 2004. The regulation of bacterial transcription initiation. Nat. Rev. Microbiol. 2: 5765.
19. Burgess, R. R., and, L. Anthony. 2001. How sigma docks to RNA polymerase and what sigma does. Curr. Opin. Microbiol. 4: 126131.
20. Butcher, B. G., T. Mascher, and, J. D. Helmann. 2008. Environmental sensing and the role of extracytoplasmic function sigma factors, P. 233–261. In W. El-Sharoud (ed.), Bacterial Physiology: A Molecular Approach. Springer-Verlag, Berlin.
21. Campbell, E. A.,, L. F. Westblade, and, S. A. Darst. 2008. Regulation of bacterial RNA polymerase sigma factor activity: a structural perspective. Curr. Opin. Microbiol. 11: 121127.
22. Chen, Y. F., and, J. D. Helmann. 1992. Restoration of motility to an Escherichia coli fliA flagellar mutant by a Bacillus subtilis sigma factor. Proc. Natl. Acad. Sci. USA 89: 51235127.
23. Chilcott, G. S., and, K. T. Hughes. 2000. Coupling of flagellar gene expression to flagellar assembly in Salmonella enterica serovar Typhimurium and Escherichia coli. Microbiol. Mol. Biol. Rev. 64: 694708.
24. Colland, F.,, N. Fujita,, A. Ishihama, and, A. Kolb. 2002. The interaction between sigmaS, the stationary phase sigma factor, and the core enzyme of Escherichia coli RNA polymerase. Genes Cells 7: 233247.
25. Costanzo,, A., H. Nicoloff,, S. E. Barchinger,, A. B. Banta,, R. L. Gourse, and, S. E. Ades. 2008. ppGpp and DksA likely regulate the activity of the extracytoplasmic stress factor sigmaE in Escherichia coli by both direct and indirect mechanisms. Mol. Microbiol. 67: 619632.
26. Dupuy,, B., S. Raffestin,, S. Matamouros,, N. Mani,, M. R. Popoff, and, A. L. Sonenshein. 2006. Regulation of toxin and bacteriocin gene expression in Clostridium by interchangeable RNA polymerase sigma factors. Mol. Microbiol. 60: 10441057.
27. Eiamphungporn, W., and, J. D. Helmann. 2008. The Bacillus subtilis sigma(M) regulon and its contribution to cell envelope stress responses. Mol. Microbiol. 67: 830848.
28. Ellermeier, C. D., and, R. Losick. 2006. Evidence for a novel protease governing regulated intramembrane proteolysis and resistance to antimicrobial peptides in Bacillus subtilis. Genes Dev. 20: 19111922.
29. Errington, J. 2003. Regulation of endospore formation in Bacillus subtilis. Nat. Rev. Microbiol. 1: 117126.
30. Flynn, J. M.,, I. Levchenko,, R. T. Sauer, and, T. A. Baker. 2004. Modulating substrate choice: the SspB adaptor delivers a regulator of the extracytoplasmic-stress response to the AAA+ protease ClpXP for degradation. Genes Dev. 18: 22922301.
31. Francez-Charlot,, A., J. Frunzke,, C. Reichen,, J. Z. Ebneter,, B. Gourion, and, J. A. Vorholt. 2009. Sigma factor mimicry involved in regulation of general stress response. Proc. Natl. Acad. Sci. USA 106: 34673472.
32. Geszvain,, K.,, T. M. Gruber,, R. A. Mooney,, C. A. Gross, and, R. Landick. 2004. A hydrophobic patch on the flap-tip helix of E. coli RNA polymerase mediates sigma(70) region 4 function. J. Mol. Biol. 343: 569587.
33. Grossman, A. D.,, J. W. Erickson, and, C. A. Gross. 1984. The htpR gene product of E. coli is a sigma factor for heat-shock promoters. Cell 38: 383390.
34. Gruber, T. M., and, C. A. Gross. 2003. Multiple sigma subunits and the partitioning of bacterial transcription space. Annu. Rev. Microbiol. 57: 441466.
35. Guisbert,, E., T. Yura,, V. A. Rhodius, and, C. A. Gross. 2008. Convergence of molecular, modeling, and systems approaches for an understanding of the Escherichia coli heat shock response. Microbiol. Mol. Biol. Rev. 72: 545554.
36. Gummesson,, B.,, L. U. Magnusson,, M. Lovmar,, K. Kvint,, O. Persson,, M. Ballesteros,, A. Farewell, and, T. Nystrom. 2009. Increased RNA polymerase availability directs resources towards growth at the expense of maintenance. EMBO J. 28: 22092219.
37. Gutierrez-Preciado,, A.,, T. M. Henkin,, F. J. Grundy,, C. Yanofsky, and, E. Merino. 2009. Biochemical features and functional implications of the RNA-based T-box regulatory mechanism. Microbiol. Mol. Biol. Rev. 73: 3661.
38. Haldenwang, W. G. 1995. The sigma factors of Bacillus subtilis. Microbiol. Rev. 59: 130.
39. Hasselblatt,, H., R. Kurzbauer,, C. Wilken,, T. Krojer,, J. Sawa,, J. Kurt,, R. Kirk,, S. Hasenbein,, M. Ehrmann, and, T. Clausen. 2007. Regulation of the sigmaE stress response by DegS: how the PDZ domain keeps the protease inactive in the resting state and allows integration of different OMP-derived stress signals upon folding stress. Genes Dev. 21: 26592670.
40. Haugen, S. P., W. Ross, and, R. L. Gourse. 2008. Advances in bacterial promoter recognition and its control by factors that do not bind DNA. Nat. Rev. Microbiol. 6: 507519.
41. Hayden, J. D., and, S. E. Ades. 2008. The extracytoplasmic stress factor, sigmaE, is required to maintain cell envelope integrity in Escherichia coli. PLoS One 3: e1573.
42. Hecker, M.,, J. Pane-Farre, and, U. Volker. 2007. SigB-dependent general stress response in Bacillus subtilis and related grampositive bacteria. Annu. Rev. Microbiol. 61: 215236.
43. Helmann, J. D. 1991. Alternative sigma factors and the regulation of flagellar gene expression. Mol. Microbiol. 5: 28752882.
44. Helmann, J. D. 1999. Anti-sigma factors. Curr. Opin. Microbiol. 2: 135141.
45. Helmann, J. D. 2002. The extracytoplasmic function (ECF) sigma factors. Adv. Microb. Physiol. 46: 47110.
46. Helmann, J. D. 2006. Deciphering a complex genetic regulatory network: the Bacillus subtilis sigmaW protein and intrinsic resistance to antimicrobial compounds. Sci. Prog. 89: 243266.
47. Helmann, J. D. 2009. RNA polymerase: a nexus of gene regulation. Methods 47: 15.
48. Helmann, J. D., and, M. J. Chamberlin. 1988. Structure and function of bacterial sigma factors. Annu. Rev. Biochem. 57: 839872.
49. Hengge-Aronis, R. 2002a. Signal transduction and regulatory mechanisms involved in control of the sigma(S) (RpoS) subunit of RNA polymerase. Microbiol. Mol. Biol. Rev. 66: 373395., table of contents.
50. Hengge-Aronis, R. 2002b. Stationary phase gene regulation: what makes an Escherichia coli promoter sigmaS-selective? Curr. Opin. Microbiol. 5: 591595.
51. Henkin, T. M. 2008. Riboswitch RNAs: using RNA to sense cellular metabolism. Genes Dev. 22: 33833390.
52. Hilbert, D. W., and, P. J. Piggot. 2004. Compartmentalization of gene expression during Bacillus subtilis spore formation. Microbiol. Mol. Biol. Rev. 68: 234262.
53. Hughes, K. T., and, K. Mathee. 1998. The anti-sigma factors. Annu. Rev. Microbiol. 52: 231286.
54. Igoshin,, O. A.,, M. S. Brody,, C. W. Price, and, M. A. Savageau. 2007. Distinctive topologies of partner-switching signaling networks correlate with their physiological roles. J. Mol. Biol. 369: 13331352.
55. Ishihama, A. 2000. Functional modulation of Escherichia coli RNA polymerase. Annu. Rev. Microbiol. 54: 499518.
56. Jenal, U., and, R. Hengge-Aronis. 2003. Regulation by proteolysis in bacterial cells. Curr. Opin. Microbiol. 6: 163172.
57. Jordan, S.,, M. I. Hutchings, and, T. Mascher. 2008. Cell envelope stress response in gram-positive bacteria. FEMS Microbiol. Rev. 32: 107146.
58. Kill,, K.,, T. T. Binnewies,, T. Sicheritz-Ponten,, H. Willenbrock,, P. F. Hallin,, T. M. Wassenaar, and, D. W. Ussery. 2005. Genome update: sigma factors in 240 bacterial genomes. Microbiology 151: 31473150.
59. Kroos, L. 2007. The Bacillus and Myxococcus developmental networks and their transcriptional regulators. Annu. Rev. Genet. 41: 1339.
60. Lloyd, G.,, P. Landini, and, S. Busby. 2001. Activation and repression of transcription initiation in bacteria. Essays Biochem. 37: 1731.
61. Lonetto, M., M. Gribskov, and, C. A. Gross. 1992. The sigma 70 family: sequence conservation and evolutionary relationships. J. Bacteriol. 174: 38433849.
62. Lonetto,, M. A.,, K. L. Brown,, K. E. Rudd, and, M. J. Buttner. 1994. Analysis of the S treptomyces coelicolor sigE gene reveals the existence of a subfamily of eubacterial RNA polymerase sigma factors involved in the regulation of extracytoplasmic functions. Proc. Natl. Acad. Sci. USA 91: 75737577.
63. Losick, R., and, J. Pero. 1981. Cascades of Sigma factors. Cell 25: 582584.
64. Maclellan, S. R., T. Wecke, and, J. D. Helmann. 2008. A previously unidentified sigma factor and two accessory proteins regulate oxalate decarboxylase expression in Bacillus subtilis. Mol. Microbiol. 69: 954967.
65. Maeda, H.,, N. Fujita, and, A. Ishihama. 2000. Competition among seven Escherichia coli sigma subunits: relative binding affinities to the core RNA polymerase. Nucleic Acids Res. 28: 34973503.
66. Marles-Wright,, J., T. Grant,, O. Delumeau,, G. van Duinen,, S. J. Firbank,, P. J. Lewis,, J. W. Murray,, J. A. Newman,, M. B. Quin,, P. R. Race,, A. Rohou,, W. Tichelaar,, M. van Heel, and, R. J. Lewis. 2008. Molecular architecture of the “stressosome,” a signal integration and transduction hub. Science 322: 9296.
67. Marles-Wright, J., and, R. J. Lewis. 2007. Stress responses of bacteria. Curr. Opin. Struct. Biol. 17: 755760.
68. Mascher, T.,, A. B. Hachmann, and, J. D. Helmann. 2007. Regulatory overlap and functional redundancy among Bacillus subtilis extracytoplasmic function sigma factors. J. Bacteriol. 189: 69196927.
69. Mika, F., and, R. Hengge. 2005. A two-component phosphotransfer network involving ArcB, ArcA, and RssB coordinates synthesis and proteolysis of sigmaS (RpoS) in E. coli. Genes Dev. 19: 27702781.
70. Mitchell,, J. E.,, T. Oshima,, S. E. Piper,, C. L. Webster,, L. F. Westblade,, G. Karimova,, D. Ladant,, A. Kolb,, J. L. Hobman,, S. J. Busby, and, D. J. Lee. 2007. The Escherichia coli regulator of sigma 70 protein, Rsd, can up-regulate some stress-dependent promoters by sequestering sigma 70. J. Bacteriol. 189: 34893495.
71. Mooney, R. A.,, S. A. Darst, and, R. Landick. 2005. Sigma and RNA polymerase: an on-again, off-again relationship? Mol. Cell 20: 335345.
72. Nechaev, S., and, E. P. Geiduschek. 2008. Dissection of the bacteriophage T4 late promoter complex. J. Mol. Biol. 379: 402413.
73. Paget, M. S., and, J. D. Helmann. 2003. The sigma70 family of sigma factors. Genome Biol. 4: 203.
74. Pesavento,, C., G. Becker,, N. Sommerfeldt,, A. Possling,, N. Tschowri,, A. Mehlis, and, R. Hengge. 2008. Inverse regulatory coordination of motility and curli-mediated adhesion in Escherichia coli. Genes Dev. 22: 24342446.
75. Qiu, J., and, J. D. Helmann. 2001. The -10 region is a key promoter specificity determinant for the Bacillus subtilis extracytoplas-mic-function sigma factors sigma(X) and sigma(W). J. Bacteriol. 183: 19211927.
76. Raffestin, S.,, B. Dupuy,, J. C. Marvaud, and, M. R. Popoff. 2005. BotR/A and TetR are alternative RNA polymerase sigma factors controlling the expression of the neurotoxin and associated protein genes in Clostridium botulinum type A and Clostridium tetani. Mol. Microbiol. 55: 235249.
77. Raivio, T. L. 2005. Envelope stress responses and gram-negative bacterial pathogenesis. Mol. Microbiol. 56: 11191128.
78. Rappas, M.,, D. Bose, and, X. Zhang. 2007. Bacterial enhancer-binding proteins: unlocking sigma54-dependent gene transcription. Curr. Opin. Struct. Biol. 17: 110116.
79. Repoila, F.,, N. Majdalani, and, S. Gottesman. 2003. Small non-coding RNAs, co-ordinators of adaptation processes in Escherichia coli: the RpoS paradigm. Mol. Microbiol. 48: 855861.
80. Roberts, J. W., S. Shankar, and, J. J. Filter. 2008. RNA polymerase elongation factors. Annu. Rev. Microbiol. 62: 211233.
81. Rodriguez,, F., F. Arsene-Ploetze,, W. Rist,, S. Rudiger,, J. Schneider-Mergener,, M. P. Mayer, and, B. Bukau. 2008. Molecular basis for regulation of the heat shock transcription factor sigma32 by the DnaK and DnaJ chaperones. Mol. Cell. 32: 347358.
82. Roth, A., and, R. R. Breaker. 2009. The structural and functional diversity of metabolite-binding riboswitches. Annu. Rev. Biochem. 78: 305334.
83. Schobel, S.,, S. Zellmeier,, W. Schumann, and, T. Wiegert. 2004. The Bacillus subtilis σ W anti-sigma factor RsiW is degraded by intramembrane proteolysis through YluC. Mol. Microbiol. 52: 10911105.
84. Smith, T. G., and, T. R. Hoover. 2009. Deciphering bacterial flagellar gene regulatory networks in the genomic era. Adv. Appl. Microbiol. 67: 257-295.
85. Staroń,, A.,, H. J. Sofia,, S. Dietrich,, L. E. Ulrich,, H. Liesegang, and, T. Mascher. 2009. The third pillar of bacterial signal transduction: classification of the extracytoplasmic function (ECF) sigma factor protein family. Mol. Microbiol. 74: 557581.
86. Typas, A.,, C. Barembruch,, A. Possling, and, R. Hengge. 2007a. Stationary phase reorganisation of the Escherichia coli transcription machinery by Crl protein, a fine-tuner of sigmas activity and levels. EMBO J. 26: 15691578.
87. Typas, A.,, G. Becker, and, R. Hengge. 2007b. The molecular basis of selective promoter activation by the sigmaS subunit of RNA polymerase. Mol. Microbiol. 63: 12961306.
88. Walsh,, N. P.,, B. M. Alba,, B. Bose,, C. A. Gross, and, R. T. Sauer. 2003. OMP peptide signals initiate the envelope-stress response by activating DegS protease via relief of inhibition mediated by its PDZ domain. Cell 113: 6171.
89. Wigneshweraraj,, S., D. Bose,, P. C. Burrows,, N. Joly,, J. Schumacher,, M. Rappas,, T. Pape,, X. Zhang,, P. Stockley,, K. Severinov, and, M. Buck. 2008. Modus operandi of the bacterial RNA polymerase containing the sigma54 promoter-specificity factor. Mol. Microbiol. 68: 538546.
90. Wood, L. F., and, D. E. Ohman. 2009. Use of cell wall stress to characterize sigma 22 (AlgT/U) activation by regulated proteolysis and its regulon in Pseudomonas aeruginosa. Mol. Microbiol. 72: 183201.
91. Yang, X.,, C. M. Kang,, M. S. Brody, and, C. W. Price. 1996. Opposing pairs of serine protein kinases and phosphatases transmit signals of environmental stress to activate a bacterial transcription factor. Genes Dev. 10: 22652275.
92. Yura,, T., E. Guisbert,, M. Poritz,, C. Z. Lu,, E. Campbell, and, C. A. Gross. 2007. Analysis of sigma32 mutants defective in chaperone-mediated feedback control reveals unexpected complexity of the heat shock response. Proc. Natl. Acad. Sci. USA 104: 1763817643.
93. Zellmeier, S.,, W. Schumann, and, T. Wiegert. 2006. Involvement of Clp protease activity in modulating the Bacillus subtilis σ W stress response. Mol. Microbiol. 61: 15691582.
94. Zhou,, Y., S. Gottesman,, J. R. Hoskins,, M. R. Maurizi, and, S. Wickner. 2001. The RssB response regulator directly targets sigma(S) for degradation by ClpXP. Genes Dev. 15: 627637.


Generic image for table
Table 1.

σ family factors of and

Citation: Helmann J. 2011. Regulation by Alternative Sigma Factors, p 31-43. In Storz G, Hengge R (ed), Bacterial Stress Responses, Second Edition. ASM Press, Washington, DC. doi: 10.1128/9781555816841.ch3

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