| Structural highlights
Function
[R1AB_CVHSA] The replicase polyprotein of coronaviruses is a multifunctional protein: it contains the activities necessary for the transcription of negative stranded RNA, leader RNA, subgenomic mRNAs and progeny virion RNA as well as proteinases responsible for the cleavage of the polyprotein into functional products (By similarity).[1] [2] [3] The papain-like proteinase (PL-PRO) is responsible for the cleavages located at the N-terminus of replicase polyprotein. In addition, PL-PRO possesses a deubiquitinating/deISGylating activity and processes both 'Lys-48'- and 'Lys-63'-linked polyubiquitin chains from cellular substrates. Antagonizes innate immune induction of type I interferon by blocking the phosphorylation, dimerization and subsequent nuclear translocation of host IRF-3.[4] [5] [6] The main proteinase 3CL-PRO is responsible for the majority of cleavages as it cleaves the C-terminus of replicase polyprotein at 11 sites. Recognizes substrates containing the core sequence [ILMVF]-Q-|-[SGACN]. Inhibited by the substrate-analog Cbz-Val-Asn-Ser-Thr-Leu-Gln-CMK (By similarity). Also contains an ADP-ribose-1-phosphate (ADRP)-binding function.[7] [8] [9] The helicase which contains a zinc finger structure displays RNA and DNA duplex-unwinding activities with 5' to 3' polarity. Its ATPase activity is strongly stimulated by poly(U), poly(dT), poly(C), poly(dA), but not by poly(G). Activity of helicase is dependent on magnesium.[10] [11] [12] The exoribonuclease acts on both ssRNA and dsRNA in a 3' to 5' direction.[13] [14] [15] Nsp7-nsp8 hexadecamer may possibly confer processivity to the polymerase, maybe by binding to dsRNA or by producing primers utilized by the latter.[16] [17] [18] Nsp9 is a ssRNA-binding protein.[19] [20] [21] NendoU is a Mn(2+)-dependent, uridylate-specific enzyme, which leaves 2'-3'-cyclic phosphates 5' to the cleaved bond.[22] [23] [24]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Mature nonstructural protein-15 (nsp15) from the severe acute respiratory syndrome coronavirus (SARS-CoV) contains a novel uridylate-specific Mn2+-dependent endoribonuclease (NendoU). Structure studies of the full-length form of the obligate hexameric enzyme from two CoVs, SARS-CoV and murine hepatitis virus, and its monomeric homologue, XendoU from Xenopus laevis, combined with mutagenesis studies have implicated several residues in enzymatic activity and the N-terminal domain as the major determinant of hexamerization. However, the tight link between hexamerization and enzyme activity in NendoUs has remained an enigma. Here, we report the structure of a trimmed, monomeric form of SARS-CoV nsp15 (residues 28 to 335) determined to a resolution of 2.9 A. The catalytic loop (residues 234 to 249) with its two reactive histidines (His 234 and His 249) is dramatically flipped by approximately 120 degrees into the active site cleft. Furthermore, the catalytic nucleophile Lys 289 points in a diametrically opposite direction, a consequence of an outward displacement of the supporting loop (residues 276 to 295). In the full-length hexameric forms, these two loops are packed against each other and are stabilized by intimate intersubunit interactions. Our results support the hypothesis that absence of an adjacent monomer due to deletion of the hexamerization domain is the most likely cause for disruption of the active site, offering a structural basis for why only the hexameric form of this enzyme is active.
Crystal structure of a monomeric form of severe acute respiratory syndrome coronavirus endonuclease nsp15 suggests a role for hexamerization as an allosteric switch.,Joseph JS, Saikatendu KS, Subramanian V, Neuman BW, Buchmeier MJ, Stevens RC, Kuhn P J Virol. 2007 Jun;81(12):6700-8. Epub 2007 Apr 4. PMID:17409150[25]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Imbert I, Guillemot JC, Bourhis JM, Bussetta C, Coutard B, Egloff MP, Ferron F, Gorbalenya AE, Canard B. A second, non-canonical RNA-dependent RNA polymerase in SARS coronavirus. EMBO J. 2006 Oct 18;25(20):4933-42. Epub 2006 Oct 5. PMID:17024178 doi:7601368
- ↑ Lindner HA, Lytvyn V, Qi H, Lachance P, Ziomek E, Menard R. Selectivity in ISG15 and ubiquitin recognition by the SARS coronavirus papain-like protease. Arch Biochem Biophys. 2007 Oct 1;466(1):8-14. Epub 2007 Jul 14. PMID:17692280 doi:10.1016/j.abb.2007.07.006
- ↑ Frieman M, Ratia K, Johnston RE, Mesecar AD, Baric RS. Severe acute respiratory syndrome coronavirus papain-like protease ubiquitin-like domain and catalytic domain regulate antagonism of IRF3 and NF-kappaB signaling. J Virol. 2009 Jul;83(13):6689-705. doi: 10.1128/JVI.02220-08. Epub 2009 Apr 15. PMID:19369340 doi:10.1128/JVI.02220-08
- ↑ Imbert I, Guillemot JC, Bourhis JM, Bussetta C, Coutard B, Egloff MP, Ferron F, Gorbalenya AE, Canard B. A second, non-canonical RNA-dependent RNA polymerase in SARS coronavirus. EMBO J. 2006 Oct 18;25(20):4933-42. Epub 2006 Oct 5. PMID:17024178 doi:7601368
- ↑ Lindner HA, Lytvyn V, Qi H, Lachance P, Ziomek E, Menard R. Selectivity in ISG15 and ubiquitin recognition by the SARS coronavirus papain-like protease. Arch Biochem Biophys. 2007 Oct 1;466(1):8-14. Epub 2007 Jul 14. PMID:17692280 doi:10.1016/j.abb.2007.07.006
- ↑ Frieman M, Ratia K, Johnston RE, Mesecar AD, Baric RS. Severe acute respiratory syndrome coronavirus papain-like protease ubiquitin-like domain and catalytic domain regulate antagonism of IRF3 and NF-kappaB signaling. J Virol. 2009 Jul;83(13):6689-705. doi: 10.1128/JVI.02220-08. Epub 2009 Apr 15. PMID:19369340 doi:10.1128/JVI.02220-08
- ↑ Imbert I, Guillemot JC, Bourhis JM, Bussetta C, Coutard B, Egloff MP, Ferron F, Gorbalenya AE, Canard B. A second, non-canonical RNA-dependent RNA polymerase in SARS coronavirus. EMBO J. 2006 Oct 18;25(20):4933-42. Epub 2006 Oct 5. PMID:17024178 doi:7601368
- ↑ Lindner HA, Lytvyn V, Qi H, Lachance P, Ziomek E, Menard R. Selectivity in ISG15 and ubiquitin recognition by the SARS coronavirus papain-like protease. Arch Biochem Biophys. 2007 Oct 1;466(1):8-14. Epub 2007 Jul 14. PMID:17692280 doi:10.1016/j.abb.2007.07.006
- ↑ Frieman M, Ratia K, Johnston RE, Mesecar AD, Baric RS. Severe acute respiratory syndrome coronavirus papain-like protease ubiquitin-like domain and catalytic domain regulate antagonism of IRF3 and NF-kappaB signaling. J Virol. 2009 Jul;83(13):6689-705. doi: 10.1128/JVI.02220-08. Epub 2009 Apr 15. PMID:19369340 doi:10.1128/JVI.02220-08
- ↑ Imbert I, Guillemot JC, Bourhis JM, Bussetta C, Coutard B, Egloff MP, Ferron F, Gorbalenya AE, Canard B. A second, non-canonical RNA-dependent RNA polymerase in SARS coronavirus. EMBO J. 2006 Oct 18;25(20):4933-42. Epub 2006 Oct 5. PMID:17024178 doi:7601368
- ↑ Lindner HA, Lytvyn V, Qi H, Lachance P, Ziomek E, Menard R. Selectivity in ISG15 and ubiquitin recognition by the SARS coronavirus papain-like protease. Arch Biochem Biophys. 2007 Oct 1;466(1):8-14. Epub 2007 Jul 14. PMID:17692280 doi:10.1016/j.abb.2007.07.006
- ↑ Frieman M, Ratia K, Johnston RE, Mesecar AD, Baric RS. Severe acute respiratory syndrome coronavirus papain-like protease ubiquitin-like domain and catalytic domain regulate antagonism of IRF3 and NF-kappaB signaling. J Virol. 2009 Jul;83(13):6689-705. doi: 10.1128/JVI.02220-08. Epub 2009 Apr 15. PMID:19369340 doi:10.1128/JVI.02220-08
- ↑ Imbert I, Guillemot JC, Bourhis JM, Bussetta C, Coutard B, Egloff MP, Ferron F, Gorbalenya AE, Canard B. A second, non-canonical RNA-dependent RNA polymerase in SARS coronavirus. EMBO J. 2006 Oct 18;25(20):4933-42. Epub 2006 Oct 5. PMID:17024178 doi:7601368
- ↑ Lindner HA, Lytvyn V, Qi H, Lachance P, Ziomek E, Menard R. Selectivity in ISG15 and ubiquitin recognition by the SARS coronavirus papain-like protease. Arch Biochem Biophys. 2007 Oct 1;466(1):8-14. Epub 2007 Jul 14. PMID:17692280 doi:10.1016/j.abb.2007.07.006
- ↑ Frieman M, Ratia K, Johnston RE, Mesecar AD, Baric RS. Severe acute respiratory syndrome coronavirus papain-like protease ubiquitin-like domain and catalytic domain regulate antagonism of IRF3 and NF-kappaB signaling. J Virol. 2009 Jul;83(13):6689-705. doi: 10.1128/JVI.02220-08. Epub 2009 Apr 15. PMID:19369340 doi:10.1128/JVI.02220-08
- ↑ Imbert I, Guillemot JC, Bourhis JM, Bussetta C, Coutard B, Egloff MP, Ferron F, Gorbalenya AE, Canard B. A second, non-canonical RNA-dependent RNA polymerase in SARS coronavirus. EMBO J. 2006 Oct 18;25(20):4933-42. Epub 2006 Oct 5. PMID:17024178 doi:7601368
- ↑ Lindner HA, Lytvyn V, Qi H, Lachance P, Ziomek E, Menard R. Selectivity in ISG15 and ubiquitin recognition by the SARS coronavirus papain-like protease. Arch Biochem Biophys. 2007 Oct 1;466(1):8-14. Epub 2007 Jul 14. PMID:17692280 doi:10.1016/j.abb.2007.07.006
- ↑ Frieman M, Ratia K, Johnston RE, Mesecar AD, Baric RS. Severe acute respiratory syndrome coronavirus papain-like protease ubiquitin-like domain and catalytic domain regulate antagonism of IRF3 and NF-kappaB signaling. J Virol. 2009 Jul;83(13):6689-705. doi: 10.1128/JVI.02220-08. Epub 2009 Apr 15. PMID:19369340 doi:10.1128/JVI.02220-08
- ↑ Imbert I, Guillemot JC, Bourhis JM, Bussetta C, Coutard B, Egloff MP, Ferron F, Gorbalenya AE, Canard B. A second, non-canonical RNA-dependent RNA polymerase in SARS coronavirus. EMBO J. 2006 Oct 18;25(20):4933-42. Epub 2006 Oct 5. PMID:17024178 doi:7601368
- ↑ Lindner HA, Lytvyn V, Qi H, Lachance P, Ziomek E, Menard R. Selectivity in ISG15 and ubiquitin recognition by the SARS coronavirus papain-like protease. Arch Biochem Biophys. 2007 Oct 1;466(1):8-14. Epub 2007 Jul 14. PMID:17692280 doi:10.1016/j.abb.2007.07.006
- ↑ Frieman M, Ratia K, Johnston RE, Mesecar AD, Baric RS. Severe acute respiratory syndrome coronavirus papain-like protease ubiquitin-like domain and catalytic domain regulate antagonism of IRF3 and NF-kappaB signaling. J Virol. 2009 Jul;83(13):6689-705. doi: 10.1128/JVI.02220-08. Epub 2009 Apr 15. PMID:19369340 doi:10.1128/JVI.02220-08
- ↑ Imbert I, Guillemot JC, Bourhis JM, Bussetta C, Coutard B, Egloff MP, Ferron F, Gorbalenya AE, Canard B. A second, non-canonical RNA-dependent RNA polymerase in SARS coronavirus. EMBO J. 2006 Oct 18;25(20):4933-42. Epub 2006 Oct 5. PMID:17024178 doi:7601368
- ↑ Lindner HA, Lytvyn V, Qi H, Lachance P, Ziomek E, Menard R. Selectivity in ISG15 and ubiquitin recognition by the SARS coronavirus papain-like protease. Arch Biochem Biophys. 2007 Oct 1;466(1):8-14. Epub 2007 Jul 14. PMID:17692280 doi:10.1016/j.abb.2007.07.006
- ↑ Frieman M, Ratia K, Johnston RE, Mesecar AD, Baric RS. Severe acute respiratory syndrome coronavirus papain-like protease ubiquitin-like domain and catalytic domain regulate antagonism of IRF3 and NF-kappaB signaling. J Virol. 2009 Jul;83(13):6689-705. doi: 10.1128/JVI.02220-08. Epub 2009 Apr 15. PMID:19369340 doi:10.1128/JVI.02220-08
- ↑ Joseph JS, Saikatendu KS, Subramanian V, Neuman BW, Buchmeier MJ, Stevens RC, Kuhn P. Crystal structure of a monomeric form of severe acute respiratory syndrome coronavirus endonuclease nsp15 suggests a role for hexamerization as an allosteric switch. J Virol. 2007 Jun;81(12):6700-8. Epub 2007 Apr 4. PMID:17409150 doi:10.1128/JVI.02817-06
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