PROSITE documentation PDOC51538
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 <PDOC51493>). 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.

Last update:

June 2011 / First entry.


Technical section

PROSITE method (with tools and information) covered by this documentation:

AV_CP, PS51538; Arterivirus nsp2 cysteine protease (AV CP) domain profile  (MATRIX)


1AuthorsSnijder E.J. Wassenaar A.L.M. Spaan W.J.M. Gorbalenya A.E.
TitleThe arterivirus Nsp2 protease. An unusual cysteine protease with primary structure similarities to both papain-like and chymotrypsin-like proteases.
SourceJ. Biol. Chem. 270:16671-16676(1995).
PubMed ID7622476

2AuthorsWassenaar A.L.M. Spaan W.J.M. Gorbalenya A.E. Snijder E.J.
TitleAlternative proteolytic processing of the arterivirus replicase ORF1a polyprotein: evidence that NSP2 acts as a cofactor for the NSP4 serine protease.
SourceJ. Virol. 71:9313-9322(1997).
PubMed ID9371590

3AuthorsZiebuhr J. Snijder E.J. Gorbalenya A.E.
TitleVirus-encoded proteinases and proteolytic processing in the Nidovirales.
SourceJ. Gen. Virol. 81:853-879(2000).
PubMed ID10725411



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