IUBMB Enzyme Nomenclature


Accepted name: infectious pancreatic necrosis birnavirus Vp4 peptidase

Reaction: Cleaves the (Ser/Thr)-Xaa-Ala(Ser/Ala)-Gly motif in the polyprotein NH2-pVP2-VP4-VP3-COOH of infectious pancreatic necrosis virus at the pVP2-VP4 and VP4-VP3 junctions

Other name(s): infectious pancreatic necrosis virus protease; IPNV Vp4 protease; IPNV Vp4 peptidase; NS protease; NS-associated protease; Vp4 protease

Comments: Infectious pancreatic necrosis virus (IPNV) is a birnavirus that causes an acute, contagious disease in young salmonid fish [2]. As with most viruses that infect eukaryotic cells, the proteolytic processing of viral precursor proteins is a crucial step in the life cycle of this virus [2]. pVP2 is converted into VP2 by cleavage near the carboxy end of pVP2. This cleavage is most likely due to host-cell proteases rather than VP4 [2,3]. Differs from most serine peptidases in not having the catalytic triad Ser-His-Asp [2]. Belongs in peptidase family S50.

Links to other databases: BRENDA, EXPASY, KEGG, MEROPS, Metacyc, PDB, CAS registry number:


1. Manning, D.S. and Leong, J.C. Expression in Escherichia coli of the large genomic segment of infectious pancreatic necrosis virus. Virology 179 (1990) 16-25. [PMID: 2219718]

2. Petit, S., Lejal, N., Huet, J.C. and Delmas, B. Active residues and viral substrate cleavage sites of the protease of the birnavirus infectious pancreatic necrosis virus. J. Virol. 74 (2000) 2057-2066. [PMID: 10666235]

3. Dobos, P. The molecular biology of infectious pancreatic necrosis virus (IPNV). Annu. Rev. Fish Dis. 5 (1995) 25-54.

[EC created 2006]

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