Chapter 7 : Cell Biology of Nidovirus Replication Complexes

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Viruses are obligate intracellular parasites that modify the host cell to generate an environment for optimal production of progeny virus. Positive-strand RNA viruses modify intracellular membranes to generate “factories” for viral RNA synthesis. These factories are made up of viral replicase proteins and host cell membranes that assemble to form novel structures, which can be visualized by electron microscopy (EM). For example, the replication complex of brome mosaic virus, a positive-strand RNA virus of plants, induces invaginations and spherule formation in the endoplasmic reticulum (ER). These spherules sequester the viral genomic RNA and polymerase together and allow for the efficient synthesis of viral genomic and subgenomic mRNAs. The replication complexes of hepatitis C virus form a membranous web in the cytoplasm of hepatoma cells. This membranous web may provide an environment for persistence of viral RNA during chronic infection. For nidoviruses, a striking feature is that viral replicase proteins induce the formation of double-membrane vesicles (DMVs), which are the sites of viral RNA synthesis. This chapter reviews the current literature on the visualization and assembly of nidovirus DMVs, and describes recent studies that provide insight into the possible host cell pathways subverted by the viral replication complexes to help generate these factories for nidovirus RNA synthesis.

Citation: Baker S, Denison M. 2008. Cell Biology of Nidovirus Replication Complexes, p 103-113. In Perlman S, Gallagher T, Snijder E (ed), Nidoviruses. ASM Press, Washington, DC. doi: 10.1128/9781555815790.ch7

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Porcine reproductive and respiratory syndrome virus
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Image of Figure 1.
Figure 1.

Schematic diagram of nidovirus replicase domains illustrating the conservation of proteolytic processing and enzymatic activity in arteri-, corona-, toro-, and ronivirus families. Connected arrows indicate confirmed cleavage sites processed by the indicated protease. Arrowheads indicate predicted sites for proteolytic processing. Abbreviations: PCP/P1/P2/PL, papain-like cysteine proteases; CP, cysteine protease; A, ADP-ribose- 1” -phosphatase; SP, serine protease; 3CL, 3C-like protease (also termed M); RdRp, RNA-dependent RNA polymerase; Z, zinc-binding domain; Hel, helicase; NendoU, nidovirus uridylate-specific endoribonuclease; ExoN, exonuclease; MT, methyltransferase.

Citation: Baker S, Denison M. 2008. Cell Biology of Nidovirus Replication Complexes, p 103-113. In Perlman S, Gallagher T, Snijder E (ed), Nidoviruses. ASM Press, Washington, DC. doi: 10.1128/9781555815790.ch7
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Image of Figure 2.
Figure 2.

Cascade of proteolytic processing for murine coronavirus replicase polyprotein. Processing by papain-like proteases (PLP1 and PLP2) and 3CL is indicated by the arrows. Intermediates nsp2-3 ( ) and nsp4-10 ( ) have been detected in pulse-chase studies. nsp4-16 is proposed based on a protein band of >450 kDa. Ne-U, nidovirus uridylate-specific endoribonuclease; for other abbreviations, see legend to Fig. 1 .

Citation: Baker S, Denison M. 2008. Cell Biology of Nidovirus Replication Complexes, p 103-113. In Perlman S, Gallagher T, Snijder E (ed), Nidoviruses. ASM Press, Washington, DC. doi: 10.1128/9781555815790.ch7
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Image of Figure 3.
Figure 3.

Transmission EM analysis of membrane alterations in nidovirus-infected cells. (A and B) DMV formation in EAV-infected BHK-21 cells at 4 postinfection. Bar, 100 nm. (C) Formation of DMVs from paired ER membranes upon EAV nsp2-3 expression in BHK-21 cells at 8 h posttransfection. Bar, 100 nm. (D) DMVs seen in MHV-A59-infected 17cl-1 cells at 7 postinfection. The double membrane is fused into a trilayer (arrowheads). Bar, 100 nm. (E) Analysis of SARS-CoV-infected Vero-E6 cells cryofixed by high-speed plunge freezing in liquid ethane, a step followed by freeze substitution with 1% osmium tetroxide and 0.5% uranyl acetate in acetone and embedment in epoxy LX-112 resin. The arrow indicates apparent continuity between the other membrane of a DMV and a mitochondrion (M), which was occasionally observed. Bar, 250 nm. (F) Ultrastructural characteristics of a broncho alveolar lavage specimen from a patient with SARS. DMVs (arrow) are shown to contain diffuse, granular material. Bar, 1 μm. Reproduced with permission from Pedersen et al., 1999 (A); Snijder et al., 2001 (B and C); Gosert et al., 2002 (D); Snijder et al., 2006 (E); and Goldsmith et al., 2004 (public access) (F).

Citation: Baker S, Denison M. 2008. Cell Biology of Nidovirus Replication Complexes, p 103-113. In Perlman S, Gallagher T, Snijder E (ed), Nidoviruses. ASM Press, Washington, DC. doi: 10.1128/9781555815790.ch7
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Image of Figure 4.
Figure 4.

Models of nidovirus replicase proteins driving formation of DMVs and replication of viral RNA. Nidovirus replicase complexes are depicted as gray circles; viral positive-strand RNA is depicted as a solid line, and negative-strand RNA is depicted as a dotted line. (A) DMV formation sequesters viral genomic RNA for transcription and replication. (B) DMV formation generates a catalytic surface area competent for transcription and replication of viral RNA.

Citation: Baker S, Denison M. 2008. Cell Biology of Nidovirus Replication Complexes, p 103-113. In Perlman S, Gallagher T, Snijder E (ed), Nidoviruses. ASM Press, Washington, DC. doi: 10.1128/9781555815790.ch7
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1. Almazan, F.,, J. M. Gonzalez,, Z. Penzes,, A. Izeta,, E. Calvo,, J. Plana-Duran, and, L. Enjuanes. 2000. Engineering the largest RNA virus genome as an infectious bacterial artificial chromosome. Proc. Natl. Acad. Sci. USA 97:55165521.
2. Anand, K.,, G. J. Palm,, J. R. Mesters,, S. G. Siddell,, J. Ziebuhr, and, R. Hilgenfeld. 2002. Structure of coronavirus main proteinase reveals combination of a chymotrypsin fold with an extra alpha-helical domain. EMBO J. 21:32133224.
3. Anand, K.,, J. Ziebuhr,, P. Wadhwani,, J. R. Mesters, and, R. Hilgenfeld. 2003. Coronavirus main proteinase (3CLpro) structure: basis for design of anti-SARS drugs. Science 300:17631767.
4. Barrette-Ng, I. H.,, K. K. Ng,, B. L. Mark,, D. Van Aken,, M. M. Cherney,, C. Garen,, Y. Kolodenko,, A. E. Gorbalenya,, E. J. Snijder, and, M. N. James. 2002. Structure of arterivirus nsp4. The smallest chymotrypsin-like proteinase with an alpha/beta C-terminal extension and alternate conformations of the oxyanion hole. J. Biol. Chem. 277:3996039966.
5. Barretto, N.,, D. Jukneliene,, K. Ratia,, Z. Chen,, A. D. Mesecar, and, S. C. Baker. 2005. The papain-like protease of severe acute respiratory syndrome coronavirus has deubiquitinating activity. J. Virol. 79:1518915198.
6. Bernales, S.,, K. L. McDonald, and, P. Walter. 2006. Autophagy counterbalances endoplasmic reticulum expansion during the unfolded protein response. PLoS Biol. 4:e423.
7. Bi, W.,, J. D. Pinon,, S. Hughes,, P. J. Bonilla,, K. V. Holmes,, S. R. Weiss, and, J. L. Leibowitz. 1998. Localization of mouse hepatitis virus open reading frame 1A derived proteins. J. Neurovirol. 4:594605.
8. Bienz, K.,, D. Egger,, T. Pfister, and, M. Troxler. 1992. Structural and functional characterization of the poliovirus replication complex. J. Virol. 66:27402747.
9. Bienz, K.,, D. Egger,, M. Troxler, and, L. Pasamontes. 1990. Structural organization of poliovirus RNA replication is mediated by viral proteins of the P2 genomic region. J. Virol. 64:11561163.
10. Bost, A. G.,, R. H. Carnahan,, X. T. Lu, and, M. R. Denison. 2000. Four proteins processed from the replicase gene poly-protein of mouse hepatitis virus colocalize in the cell periphery and adjacent to sites of virion assembly. J. Virol. 74:33793387.
11. Breese, S. S., and, W. H. McCollum. 1970. Electron microscopic characterization of equine arteritis virus, pp. 133–139. In proceedings of the 2nd International Conference on Equine Infectious Diseases.
12. Brockway, S. M., and, M. R. Denison. 2005. Mutagenesis of the murine hepatitis virus nsp1-coding region identifies residues important for protein processing, viral RNA synthesis, and viral replication. Virology 340:209223.
13. Casais, R.,, V. Thiel,, S. G. Siddell,, D. Cavanagh, and, P. Britton. 2001. Reverse genetics system for the avian coronavirus infectious bronchitis virus. J. Virol. 75:1235912369.
14. Coley, S. E.,, E. Lavi,, S. G. Sawicki,, L. Fu,, B. Schelle,, N. Karl,, S. G. Siddell, and, V. Thiel. 2005. Recombinant mouse hepatitis virus strain A59 from cloned, full-length cDNA replicates to high titers in vitro and is fully pathogenic in vivo. J. Virol. 79:30973106.
15. Denison, M. R.,, W. J. Spaan,, Y. van der Meer,, C. A. Gibson,, A. C. Sims,, E. Prentice, and, X. T. Lu. 1999. The putative heli-case of the coronavirus mouse hepatitis virus is processed from the replicase gene polyprotein and localizes in complexes that are active in viral RNA synthesis. J. Virol. 73:68626871.
16. Denison, M. R.,, B. Yount,, S. M. Brockway,, R. L. Graham,, A. C. Sims,, X. Lu, and, R. S. Baric. 2004. Cleavage between replicase proteins p28 and p65 of mouse hepatitis virus is not required for virus replication. J. Virol. 78:59575965.
17. Dubois-Dalcq, M.,, B. Rentier,, E. Hooghe-Peters,, M. V. Haspel,, R. L. Knobler, and, K. Holmes. 1982. Acute and persistent viral infections of differentiated nerve cells. Rev. Infect. Dis. 4:9991014.
18. Egger, D.,, N. Teterina,, E. Ehrenfeld, and, K. Bienz. 2000. Formation of the poliovirus replication complex requires coupled viral translation, vesicle production, and viral RNA synthesis. J. Virol. 74:65706580.
19. Egloff, M. P.,, F. Ferron,, V. Campanacci,, S. Longhi,, C. Rancurel,, H. Dutartre,, E. J. Snijder,, A. E. Gorbalenya,, C. Cambillau, and, B. Canard. 2004. The severe acute respiratory syndrome-coronavirus replicative protein nsp9 is a single-stranded RNA-binding subunit unique in the RNA virus world. Proc. Natl. Acad. Sci. USA 101:37923796.
20. Goldsmith, C. S.,, K. M. Tatti,, T. G. Ksiazek,, P. E. Rollin,, J. A. Comer,, W. W. Lee,, P. A. Rota,, B. Bankamp,, W. J. Bellini, and, S. R. Zaki. 2004. Ultrastructural characterization of SARS coronavirus. Emerg. Infect. Dis. 10:320326.
21. Gosert, R.,, D. Egger,, V. Lohmann,, R. Bartenschlager,, H. E. Blum,, K. Bienz, and, D. Moradpour. 2003. Identification of the hepatitis C virus RNA replication complex in Huh-7 cells harboring subgenomic replicons. J. Virol. 77:54875492.
22. Gosert, R.,, A. Kanjanahaluethai,, D. Egger,, K. Bienz, and, S. C. Baker. 2002. RNA replication of mouse hepatitis virus takes place at double-membrane vesicles. J. Virol. 76:36973708.
23. Graham, R. L., and, M. R. Denison. 2006. Replication of murine hepatitis virus is regulated by papain-like proteinase 1 processing of nonstructural proteins 1, 2, and 3. J. Virol. 80:1161011620.
24. Graham, R. L.,, A. C. Sims,, S. M. Brockway,, R. S. Baric, and, M. R. Denison. 2005. The nsp2 replicase proteins of murine hepatitis virus and severe acute respiratory syndrome corona-virus are dispensable for viral replication. J. Virol. 79:1339913411.
25. Harcourt, B. H.,, D. Jukneliene,, A. Kanjanahaluethai,, J. Bechill,, K. M. Severson,, C. M. Smith,, P. A. Rota, and, S. C. Baker. 2004. Identification of severe acute respiratory syndrome coronavirus replicase products and characterization of papain-like protease activity. J. Virol. 78:1360013612.
26. Imbert, I.,, J. C. Guillemot,, J. M. Bourhis,, C. Bussetta,, B. Coutard,, M. P. Egloff,, F. Ferron,, A. E. Gorbalenya, and, B. Canard. 2006. A second, non-canonical RNA-dependent RNA polymerase in SARS coronavirus. EMBO J. 25:49334942.
27. Ishihara, N.,, M. Hamasaki,, S. Yokota,, K. Suzuki,, Y. Kamada,, A. Kihara,, T. Yoshimori,, T. Noda, and, Y. Ohsumi. 2001. Autophagosome requires specific early Sec proteins for its formation and NSF/SNARE for vacuolar fusion. Mol. Biol. Cell 12:36903702.
28. Kanjanahaluethai, A., and, S. C. Baker. 2000. Identification of mouse hepatitis virus papain-like proteinase 2 activity. J. Virol. 74:79117921.
29. Kanjanahaluethai, A.,, Chen, Z.,, D. Jukneliene, and, S. C. Baker. 2007. Membrane topology of murine coronavirus replicase nonstructural protein 3. Virology 361:391401.
30. Kim, J. C.,, R. A. Spence,, P. F. Currier,, X. Lu, and, M. R. Denison. 1995. Coronavirus protein processing and RNA synthesis is inhibited by the cysteine proteinase inhibitor E64d. Virology 208:18.
31. Kirkegaard, K.,, M. P. Taylor, and, W. T. Jackson. 2004. Cellular autophagy: surrender, avoidance and subversion by microorganisms. Nat. Rev. Microbiol. 2:301314.
32. Lee, C.,, J. G. Calvert,, S. K. Welch, and, D. Yoo. 2005. A DNA-launched reverse genetics system for porcine reproductive and respiratory syndrome virus reveals that homodimerization of the nucleocapsid protein is essential for virus infectivity. Virology 331:4762.
33. Lee, H. J.,, C. K. Shieh,, A. E. Gorbalenya,, E. V. Koonin,, N. La Monica,, J. Tuler,, A. Bagdzhadzhyan, and, M. M. Lai. 1991. The complete sequence (22 kilobases) of murine coronavirus gene 1 encoding the putative proteases and RNA polymerase. Virology 180:567582.
34. Lindner, H. A.,, N. Fotouhi-Ardakani,, V. Lytvyn,, P. Lachance,, T. Sulea, and, R. Menard. 2005. The papain-like protease from the severe acute respiratory syndrome coronavirus is a deubiquitinating enzyme. J. Virol. 79:1519915208.
35. Lyle, J. M.,, E. Bullitt,, K. Bienz, and, K. Kirkegaard. 2002. Visualization and functional analysis of RNA-dependent RNA polymerase lattices. Science 296:22182222.
36. Masters, P. S. 2006. The molecular biology of coronaviruses. Adv. Virus Res. 66:193292.
37. Minskaia, E.,, T. Hertzig,, A. E. Gorbalenya,, V. Campanacci,, C. Cambillau,, B. Canard, and, J. Ziebuhr. 2006. Discovery of an RNA virus 3ˊ—5ˊ exoribonuclease that is critically involved in coronavirus RNA synthesis. Proc. Natl. Acad. Sci. USA 103:51085113.
38. Nielsen, H. S.,, G. Liu,, J. Nielsen,, M. B. Oleksiewicz,, A. Botner,, T. Storgaard, and, K. S. Faaberg. 2003. Generation of an infectious clone of VR-2332, a highly virulent North American-type isolate of porcine reproductive and respiratory syndrome virus. J. Virol. 77:37023711.
39. Ogata, M.,, S. Hino,, A. Saito,, K. Morikawa,, S. Kondo,, S. Kanemoto,, T. Murakami,, M. Taniguchi,, I. Tanii,, K. Yoshinaga,, S. Shiosaka,, J. A. Hammarback,, F. Urano, and, K. Imaizumi. 2006. Autophagy is activated for cell survival after endoplasmic reticulum stress. Mol. Cell. Biol. 26:92209231.
40. Pasternak, A. O.,, W. J. Spaan, and, E. J. Snijder. 2006. Nidovirus transcription: how to make sense ...? J. Gen. Virol. 87:14031421.
41. Pedersen, K. W.,, Y. van der Meer,, N. Roos, and, E. J. Snijder. 1999. Open reading frame 1a-encoded subunits of the arteri-virus replicase induce endoplasmic reticulum-derived double-membrane vesicles which carry the viral replication complex. J. Virol. 73:20162026.
42. Pinon, J. D.,, R. R. Mayreddy,, J. D. Turner,, F. S. Khan,, P. J. Bonilla, and, S. R. Weiss. 1997. Efficient autoproteolytic processing of the MHV-A59 3C-like proteinase from the flanking hydrophobic domains requires membranes. Virology 230:309322.
43. Pol, J. M.,, F. Wagenaar, and, J. E. Reus. 1997. Comparative morphogenesis of three PRRS virus strains. Vet. Microbiol. 55:203208.
44. Posthuma, C. C.,, D. D. Nedialkova,, J. C. Zevenhoven-Dobbe,, J. H. Blokhuis,, A. E. Gorbalenya, and, E. J. Snijder. 2006. Site-directed mutagenesis of the nidovirus replicative endoribonuclease NendoU exerts pleiotropic effects on the arterivirus life cycle. J. Virol. 80:16531661.
45. Prentice, E.,, W. G. Jerome,, T. Yoshimori,, N. Mizushima, and, M. R. Denison. 2004. Coronavirus replication complex formation utilizes components of cellular autophagy. J. Biol. Chem. 279:1013610141.
46. Prentice, E.,, J. McAuliffe,, X. Lu,, K. Subbarao, and, M. R. Denison. 2004. Identification and characterization of severe acute respiratory syndrome coronavirus replicase proteins. J. Virol. 78:99779986.
47. Ratia, K.,, K. S. Saikatendu,, B. D. Santarsiero,, N. Barretto,, S. C. Baker,, R. C. Stevens, and, A. D. Mesecar. 2006. Severe acute respiratory syndrome coronavirus papain-like protease: structure of a viral deubiquitinating enzyme. Proc. Natl. Acad. Sci. USA 103:57175722.
48. Reggiori, F., and, D. J. Klionsky. 2002. Autophagy in the eukaryotic cell. Eukaryot. Cell 1:1121.
49. Reggiori, F.,, C. W. Wang,, U. Nair,, T. Shintani,, H. Abeliovich, and, D. J. Klionsky. 2004. Early stages of the secretory pathway, but not endosomes, are required for Cvt vesicle and autophagosome assembly in Saccharomyces cerevisiae. Mol. Biol. Cell. 15:21892204.
50. Rust, R. C.,, L. Landmann,, R. Gosert,, B. L. Tang,, W. Hong,, H. P. Hauri,, D. Egger, and, K. Bienz. 2001. Cellular COPII proteins are involved in production of the vesicles that form the poliovirus replication complex. J. Virol. 75:98089818.
51. Saikatendu, K. S.,, J. S. Joseph,, V. Subramanian,, T. Clayton,, M. Griffith,, K. Moy,, J. Velasquez,, B. W. Neuman,, M. J. Buchmeier,, R. C. Stevens, and, P. Kuhn. 2005. Structural basis of severe acute respiratory syndrome coronavirus ADP-ribose-1 ˝-phosphate dephosphorylation by a conserved domain of nsP3. Structure (Cambridge) 13:16651675.
52. Sawicki, S. G.,, D. L. Sawicki,, D. Younker,, Y. Meyer,, V. Thiel,, H. Stokes, and, S. G. Siddell. 2005. Functional and genetic analysis of coronavirus replicase-transcriptase proteins. PLoS Pathog. 1:e39.
53. Schaad, M. C.,, S. A. Stohlman,, J. Egbert,, K. Lum,, K. Fu,, T. Wei, Jr., and, R. S. Baric. 1990. Genetics of mouse hepatitis virus transcription: identification of cistrons which may function in positive and negative strand RNA synthesis. Virology 177:634645.
54. Schiller, J. J.,, A. Kanjanahaluethai, and, S. C. Baker. 1998. Processing of the coronavirus MHV-JHM polymerase poly-protein: identification of precursors and proteolytic products spanning 400 kilodaltons of ORF1a. Virology 242:288302.
55. Schlegel, A.,, T. H. Giddings, Jr.,, M. S. Ladinsky, and, K. Kirkegaard. 1996. Cellular origin and ultrastructure of membranes induced during poliovirus infection. J. Virol. 70:65766588.
56. Schwartz, M.,, J. Chen,, M. Janda,, M. Sullivan,, J. den Boon, and, P. Ahlquist. 2002. A positive-strand RNA virus replication complex parallels form and function of retrovirus capsids. Mol. Cell 9:505514.
57. Schwartz, M.,, J. Chen,, W. M. Lee,, M. Janda, and, P. Ahlquist. 2004. Alternate, virus-induced membrane rearrangements support positive-strand RNA virus genome replication. Proc. Natl. Acad. Sci. USA 101:1126311268.
58. Sethna, P. B., and, D. A. Brian. 1997. Coronavirus genomic and subgenomic minus-strand RNAs copartition in membrane-protected replication complexes. J. Virol. 71:77447749.
59. Shi, S. T.,, J. J. Schiller,, A. Kanjanahaluethai,, S. C. Baker,, J. W. Oh, and, M. M. Lai. 1999. Colocalization and membrane association of murine hepatitis virus gene 1 products and de novo-synthesized viral RNA in infected cells. J. Virol. 73:59575969.
60. Smits, S. L.,, E. J. Snijder, and, R. J. de Groot. 2006. Characterization of a torovirus main proteinase. J. Virol. 80:41574167.
61. Snijder, E. J.,, Y. van der Meer,, J. Zevenhoven-Dobbe,, J. J. Onderwater,, J. van der Meulen,, H. K. Koerten, and, A. M. Mommaas. 2006. Ultrastructure and origin of membrane vesicles associated with the severe acute respiratory syndrome coronavirus replication complex. J. Virol. 80:59275940.
62. Snijder, E. J.,, H. van Tol,, N. Roos, and, K. W. Pedersen. 2001. Non-structural proteins 2 and 3 interact to modify host cell membranes during the formation of the arterivirus replication complex. J. Gen. Virol. 82:985994.
63. Sperry, S. M.,, L. Kazi,, R. L. Graham,, R. S. Baric,, S. R. Weiss, and, M. R. Denison. 2005. Single-amino-acid substitutions in open reading frame (ORF) 1b-nsp14 and ORF 2a proteins of the coronavirus mouse hepatitis virus are attenuating in mice. J. Virol. 79:33913400.
64. Stueckemann, J. A.,, M. Holth,, W. J. Swart,, K. Kowalchyk,, M. S. Smith,, A. J. Wolstenholme,, W. A. Cafruny, and, P. G. Plagemann. 1982. Replication of lactate dehydrogenaseelevating virus in macrophages. 2. Mechanism of persistent infection in mice and cell culture. J. Gen. Virol. 59:263272.
65. Suhy, D. A.,, T. H. Giddings, Jr., and, K. Kirkegaard. 2000. Remodeling the endoplasmic reticulum by poliovirus infection and by individual viral proteins: an autophagy-like origin for virus-induced vesicles. J. Virol. 74:89538965.
66. Sulea, T.,, H. A. Lindner,, E. O. Purisima, and, R. Ménard. 2005. Deubiquitination, a new function of the severe acute respiratory syndrome coronavirus papain-like protease? J. Virol. 79:45504551.
67. Sutton, G.,, E. Fry,, L. Carter,, S. Sainsbury,, T. Walter,, J. Nettleship,, N. Berrow,, R. Owens,, R. Gilbert,, A. Davidson,, S. Siddell,, L. L. Poon,, J. Diprose,, D. Alderton,, M. Walsh,, J. M. Grimes, and, D. I. Stuart. 2004. The nsp9 replicase protein of SARS-coronavirus, structure and functional insights. Structure 12:341353.
68. Thiel, V.,, J. Herold,, B. Schelle, and, S. G. Siddell. 2001. Infectious RNA transcribed in vitro from a cDNA copy of the human coronavirus genome cloned in vaccinia virus. J. Gen. Virol. 82:12731281.
69. Tijms, M. A.,, L. C. van Dinten,, A. E. Gorbalenya, and, E. J. Snijder. 2001. A zinc finger-containing papain-like protease couples subgenomic mRNA synthesis to genome translation in a positive-stranded RNA virus. Proc. Natl. Acad. Sci. USA 98:18891894.
70. van Aken, D.,, J. Zevenhoven-Dobbe,, A. E. Gorbalenya, and, E. J. Snijder. 2006. Proteolytic maturation of replicase poly-protein pp1a by the nsp4 main proteinase is essential for equine arteritis virus replication and includes internal cleavage of nsp7. J. Gen. Virol. 87:34733482.
71. van der Meer, Y.,, H. van Tol,, J. K. Locker, and, E. J. Snijder. 1998. ORF1a-encoded replicase subunits are involved in the membrane association of the arterivirus replication complex. J. Virol. 72:66896698.
72. van Dinten, L. C.,, J. A. den Boon,, A. L. Wassenaar,, W. J. Spaan, and, E. J. Snijder. 1997. An infectious arterivirus cDNA clone: identification of a replicase point mutation that abolishes discontinuous mRNA transcription. Proc. Natl. Acad. Sci. USA 94:991996.
73. van Dinten, L. C.,, S. Rensen,, A. E. Gorbalenya, and, E. J. Snijder. 1999. Proteolytic processing of the open reading frame 1b-encoded part of arterivirus replicase is mediated by nsp4 serine protease and is essential for virus replication. J. Virol. 73:20272037.
74. van Dinten, L. C.,, H. van Tol,, A. E. Gorbalenya, and, E. J. Snijder. 2000. The predicted metal-binding region of the arterivirus helicase protein is involved in subgenomic mRNA synthesis, genome replication, and virion biogenesis. J. Virol. 74:52135223.
75. van Dinten, L. C.,, A. L. Wassenaar,, A. E. Gorbalenya,, W. J. Spaan, and, E. J. Snijder. 1996. Processing of the equine arteritis virus replicase ORF1b protein: identification of cleavage products containing the putative viral polymerase and helicase domains. J. Virol. 70:66256633.
76. van Marle, G.,, L. C. van Dinten,, W. J. Spaan,, W. Luytjes, and, E. J. Snijder. 1999. Characterization of an equine arteritis virus replicase mutant defective in subgenomic mRNA synthesis. J. Virol. 73:52745281.
77. Wassenaar, A. L.,, W. J. Spaan,, A. E. Gorbalenya, and, E. J. Snijder. 1997. Alternative proteolytic processing of the arteri-virus replicase ORF1a polyprotein: evidence that NSP2 acts as a cofactor for the NSP4 serine protease. J. Virol. 71:93139322.
78. Wood, O.,, N. Tauraso, and, H. Liebhaber. 1970. Electron microscopic study of tissue cultures infected with simian haemorrhagic fever virus. J. Gen. Virol. 7:129136.
79. Wu, C. Y.,, J. T. Jan,, S. H. Ma,, C. J. Kuo,, H. F. Juan,, Y. S. Cheng,, H. H. Hsu,, H. C. Huang,, D. Wu,, A. Brik,, F. S. Liang,, R. S. Liu,, J. M. Fang,, S. T. Chen,, P. H. Liang, and, C. H. Wong. 2004. Small molecules targeting severe acute respiratory syndrome human coronavirus. Proc. Natl. Acad. Sci. USA 101:1001210017.
80. Xu, X.,, Y. Zhai,, F. Sun,, Z. Lou,, D. Su,, Y. Xu,, R. Zhang,, A. Joachimiak,, X. C. Zhang,, M. Bartlam, and, Z. Rao. 2006. New antiviral target revealed by the hexameric structure of mouse hepatitis virus nonstructural protein nsp15. J. Virol. 80:79097917.
81. Yang, H.,, M. Yang,, Y. Ding,, Y. Liu,, Z. Lou,, Z. Zhou,, L. Sun,, L. Mo,, S. Ye,, H. Pang,, G. F. Gao,, K. Anand,, M. Bartlam,, R. Hilgenfeld, and, Z. Rao. 2003. The crystal structures of severe acute respiratory syndrome virus main protease and its complex with an inhibitor. Proc. Natl. Acad. Sci. USA 100:1319013195.
82. Yorimitsu, T.,, U. Nair,, Z. Yang, and, D. J. Klionsky. 2006. Endoplasmic reticulum stress triggers autophagy. J. Biol. Chem. 281:3029930304.
83. Yount, B.,, K. M. Curtis, and, R. S. Baric. 2000. Strategy for systematic assembly of large RNA and DNA genomes: transmissible gastroenteritis virus model. J. Virol. 74:1060010611.
84. Yount, B.,, K. M. Curtis,, E. A. Fritz,, L. E. Hensley,, P. B. Jahrling,, E. Prentice,, M. R. Denison,, T. W. Geisbert, and, R. S. Baric. 2003. Reverse genetics with a full-length infectious cDNA of severe acute respiratory syndrome coronavirus. Proc. Natl. Acad. Sci. USA 100:1299513000.
85. Yount, B.,, M. R. Denison,, S. R. Weiss, and, R. S. Baric. 2002. Systematic assembly of a full-length infectious cDNA of mouse hepatitis virus strain A59. J. Virol. 76:1106511078.
86. Zhai, Y.,, F. Sun,, X. Li,, H. Pang,, X. Xu,, M. Bartlam, and, Z. Rao. 2005. Insights into SARS-CoV transcription and replication from the structure of the nsp7-nsp8 hexadecamer. Nat. Struct. Mol. Biol. 12:980986.
87. Ziebuhr, J. 2005. The coronavirus replicase. Curr. Top. Microbiol. Immunol. 287:5794.
88. Ziebuhr, J.,, S. Bayer,, J. A. Cowley, and, A. E. Gorbalenya. 2003. The 3C-like proteinase of an invertebrate nidovirus links coronavirus and potyvirus homologs. J. Virol. 77:14151426.

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