{PDOC51538} {PS51538; AV_CP} {BEGIN} ************************************************************* * Arterivirus nsp2 cysteine protease (AV CP) domain profile * ************************************************************* Arteriviruses are enveloped, positive-stranded RNA viruses and include pathogens of major economic concern to the swine- and horse-breeding industries [E1]: - Equine arteritis virus (EAV). - Porcine reproductive and respiratory syndrome virus (PRRSV). - Mice actate dehydrogenase-elevating virus. - Simian hemorrhagic fever virus. The arterivirus cysteine protease (AV CP) is the most carboxyl-terminally located member of the array of three cysteine proteinase domains present in the amino-terminal 500 residues of the replicase polyproteins. The AV CP is located in the amino-terminal region of nsp2 and is highly conserved among arteriviruses. The cleavage of the nsp2|3 junction appears to be the single processing step mediated by the AV CP. For EAV, it has been shown that cleaved nsp2 is an essential co-factor for cleavage of the nsp4|6 site by the nsp4 proteinase domain (see ). The AV CP is an unusual Cys protease with amino acid sequence similarities to both papain-like and chymotrypsin-like proteases. The catalytic dyad is composed of Cys and His residues [1,2,3]. The AV CP domain forms peptidase family C33 [E2]. Comparative sequence analysis and site-directed mutagenesis have characterized the AV CP as a cysteine endopeptidase whose conserved domain encompasses about 100 residues. The entire AV CP domain is highly conserved among arteriviruses. Among the conserved residues are a number of cysteines and one aspartate residues [3]. The profile we developed covers the entire AV CP domain. -Sequences known to belong to this class detected by the profile: ALL. -Other sequence(s) detected in Swiss-Prot: NONE. -Last update: June 2011 / First entry. [ 1] Snijder E.J., Wassenaar A.L.M., Spaan W.J.M., Gorbalenya A.E. "The arterivirus Nsp2 protease. An unusual cysteine protease with primary structure similarities to both papain-like and chymotrypsin-like proteases." J. Biol. Chem. 270:16671-16676(1995). PubMed=7622476 [ 2] Wassenaar A.L.M., Spaan W.J.M., Gorbalenya A.E., Snijder E.J. "Alternative proteolytic processing of the arterivirus replicase ORF1a polyprotein: evidence that NSP2 acts as a cofactor for the NSP4 serine protease." J. Virol. 71:9313-9322(1997). PubMed=9371590 [ 3] Ziebuhr J., Snijder E.J., Gorbalenya A.E. "Virus-encoded proteinases and proteolytic processing in the Nidovirales." J. Gen. Virol. 81:853-879(2000). PubMed=10725411 [E1] https://viralzone.expasy.org/284?outline=all_by_species [E2] https://www.ebi.ac.uk/merops/cgi-bin/famsum?family=c33 -------------------------------------------------------------------------------- PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see https://prosite.expasy.org/prosite_license.html -------------------------------------------------------------------------------- {END}