Family S7
Summary for family S7
| Name | Peptidase family S7 (flavivirin family) |
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| Family type peptidase | S07.001 - flavivirin (yellow fever virus), MEROPS Accession MER0000290 (peptidase unit: 1485-1666) |
| Content of family | Peptidase family S7 contains a serine endopeptidase. |
| History |
Identifier created: Biochem.J. 290:205-218 (1993)
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| Catalytic type | Serine |
| Active site residues | H1537 D1561 S1622 |
| Active site | Flavivirin 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 specificities | Flavivirin cleaves at sites like -Xaa-Xaa Yaa-, 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. |
| Inhibitors | Aprotinin (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 structure | Protein 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). |
| Clan | PA |
| Subclan | PA(S) |
| Basis of clan assignment | Protein fold of the peptidase unit for members of this family resembles that of chymotrypsin, the type example for clan PA. |
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Distribution of family
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Bacteria |
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Archaea |
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Protozoa |
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Fungi |
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Plants |
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Animals |
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Viruses |
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