Family S7


Summary Holotypes Alignment Tree Genomes Structure Literature

Summary for family S7

NamePeptidase family S7 (flavivirin family)
Family type peptidaseS07.001 - flavivirin (yellow fever virus), MEROPS Accession MER0000290 (peptidase unit: 1485-1666)
Content of familyPeptidase family S7 contains a serine endopeptidase.
History Identifier created: Biochem.J. 290:205-218 (1993)
Catalytic typeSerine
Active site residuesH1537 D1561 S1622 
Active siteFlavivirin has a catalytic triad similar to that of the peptidases in family S1: The requirement for the catalytic His, Asp and Ser residues has been demonstrated by mutagenesis of several of the viruses (e.g. Chambers et al., 1990).
Activities and specificitiesFlavivirin cleaves at sites like -Xaa-XaaYaa-, where Xaa is normally an amino acid with a basic side chain, and Yaa has a short side chain. In so doing, it makes the cleavages that generate the N-termini of several of the viral nonstructural proteins, and also makes cleavages in the C-terminal part of the capsid (Amberg et al., 1994). The activity of the enzyme against most substrates is greatly enhanced by the presence of the NS2B protein of the virus, and this complicates in vitro assays.
InhibitorsAprotinin (I02.001; Leung et al., 2001) and mung bean Bowman-Birk inhibitor (I12.001; Murthy et al., 2000) have been reported to inhibit flavivirin. Few synthetic inhibitors have been described to date.
Molecular structureProtein fold of flavivirin resembles that of chymotrypsin, the type peptidase or clan PA (Murthy et al., 2000). This, together with the similar catalytic triad residues, clearly places family S7 in subclan PA(S).
Basis of clan assignmentProtein fold of the peptidase unit for members of this family resembles that of chymotrypsin, the type example for clan PA.
Distribution of family Bacteria -  
Archaea -  
Protozoa -  
Fungi -  
Plants -  
Animals details  
Viruses details  
Biological functions
Pharmaceutical and biotech relevanceThe enzyme is a potential drug target because of the importance of diseases caused by flaviviruses.
Statistics for family S7Sequences:124
Identifiers with PDB entries:3
Downloadable files Sequence library (FastA format)
Sequence alignment (FastA format)
Phylogenetic tree (Newick format)
Peptidases and Homologues MEROPS ID Structure
Zika virus NS2B-NS3 peptidaseS07.003Yes
family S7 non-peptidase homologuesnon-peptidase homologue-
family S7 unassigned peptidasesunassignedYes