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ENZYME entry: EC

Accepted Name
equine arterivirus serine peptidase
Alternative Name(s)
3C-like serine protease
3C-like Ser protease
arterivirus NSP4
chymotrypsin-like serine proteinase nsp4
equine arteritis virus serine peptidase
non-structural protein 4 serine protease
Reaction catalysed
Cleavage of (Glu/Gln)-|-(Gly/Ser/Ala) in arterivirus replicase translation products ORF1a and ORF1ab
  • In the equine arterivirus (EAV), the replicase gene is translated into open reading frame 1a (ORF1a) and ORF1ab polyproteins.
  • This enzyme is the main viral proteinase and processes five cleavage sites in the ORF1a protein and three in the ORF1b-encoded part of the ORF1ab protein to yield non-structural proteins (nsp5-nsp12).
  • It combines the catalytic system of a chymotrypsin-like serine peptidase (His-Asp-Ser catalytic triad) with the substrate specificity of a 3C-like serine peptidase (Glu or Gln) at the P1 position and a small amino-acid residue (Gly, Ser or Ala) at the P1' position.
  • Cleavage of ORF1ab by this enzyme is essential for viral replication.
  • Belongs to peptidase family S32.
PRIAM enzyme-specific profiles3.4.21.114
KEGG Ligand Database for Enzyme Nomenclature3.4.21.114
IUBMB Enzyme Nomenclature3.4.21.114
MEDLINEFind literature relating to
Rhea expert-curated reactions3.4.21.114

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