View source for 2hob

==Crystal structure of SARS-CoV main protease with authentic N and C-termini in complex with a Michael acceptor N3==
<StructureSection load='2hob' size='340' side='right' caption='[[2hob]], [[Resolution|resolution]] 1.95&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2hob]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Cvhsa Cvhsa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HOB OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2HOB FirstGlance]. <br>
</td></tr><tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=010:PHENYLMETHANOL'>010</scene>, <scene name='pdbligand=02J:5-METHYL-1,2-OXAZOLE-3-CARBOXYLIC+ACID'>02J</scene>, <scene name='pdbligand=PJE:(E,4S)-4-AZANYL-5-[(3S)-2-OXIDANYLIDENEPYRROLIDIN-3-YL]PENT-2-ENOIC+ACID'>PJE</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2hob FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2hob OCA], [http://pdbe.org/2hob PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2hob RCSB], [http://www.ebi.ac.uk/pdbsum/2hob PDBsum]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/R1AB_CVHSA 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).<ref>PMID:17024178</ref> <ref>PMID:17692280</ref> <ref>PMID:19369340</ref>   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.<ref>PMID:17024178</ref> <ref>PMID:17692280</ref> <ref>PMID:19369340</ref>   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.<ref>PMID:17024178</ref> <ref>PMID:17692280</ref> <ref>PMID:19369340</ref>   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.<ref>PMID:17024178</ref> <ref>PMID:17692280</ref> <ref>PMID:19369340</ref>   The exoribonuclease acts on both ssRNA and dsRNA in a 3' to 5' direction.<ref>PMID:17024178</ref> <ref>PMID:17692280</ref> <ref>PMID:19369340</ref>   Nsp7-nsp8 hexadecamer may possibly confer processivity to the polymerase, maybe by binding to dsRNA or by producing primers utilized by the latter.<ref>PMID:17024178</ref> <ref>PMID:17692280</ref> <ref>PMID:19369340</ref>   Nsp9 is a ssRNA-binding protein.<ref>PMID:17024178</ref> <ref>PMID:17692280</ref> <ref>PMID:19369340</ref>   NendoU is a Mn(2+)-dependent, uridylate-specific enzyme, which leaves 2'-3'-cyclic phosphates 5' to the cleaved bond.<ref>PMID:17024178</ref> <ref>PMID:17692280</ref> <ref>PMID:19369340</ref>  
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ho/2hob_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
The viral proteases have proven to be the most selective and useful for removing the fusion tags in fusion protein expression systems. As a key enzyme in the viral life-cycle, the main protease (M(pro)) is most attractive for drug design targeting the SARS coronavirus (SARS-CoV), the etiological agent responsible for the outbreak of severe acute respiratory syndrome (SARS) in 2003. In this study, SARS-CoV M(pro) was used to specifically remove the GST tag in a new fusion protein expression system. We report a new method to produce wild-type (WT) SARS-CoV M(pro) with authentic N and C termini, and compare the activity of WT protease with those of three different types of SARS-CoV M(pro) with additional residues at the N or C terminus. Our results show that additional residues at the N terminus, but not at the C terminus, of M(pro) are detrimental to enzyme activity. To explain this, the crystal structures of WT SARS-CoV M(pro) and its complex with a Michael acceptor inhibitor were determined to 1.6 Angstroms and 1.95 Angstroms resolution respectively. These crystal structures reveal that the first residue of this protease is important for sustaining the substrate-binding pocket and inhibitor binding. This study suggests that SARS-CoV M(pro) could serve as a new tag-cleavage endopeptidase for protein overproduction, and the WT SARS-CoV M(pro) is more appropriate for mechanistic characterization and inhibitor design.

Production of authentic SARS-CoV M(pro) with enhanced activity: application as a novel tag-cleavage endopeptidase for protein overproduction.,Xue X, Yang H, Shen W, Zhao Q, Li J, Yang K, Chen C, Jin Y, Bartlam M, Rao Z J Mol Biol. 2007 Feb 23;366(3):965-75. Epub 2006 Dec 1. PMID:17189639<ref>PMID:17189639</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 2hob" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Cvhsa]]
[[Category: Li, J]]
[[Category: Rao, Z]]
[[Category: Shen, W]]
[[Category: Xue, X]]
[[Category: Yang, H]]
[[Category: Zhao, Q]]
[[Category: Main protease]]
[[Category: Michael acceptor n3]]
[[Category: Sars-cov]]
[[Category: Viral protein]]