Family S30
Summary for family S30
| Family type peptidase | S30.001 - potyvirus P1 peptidase (plum pox virus), MEROPS Accession MER0000297 (peptidase unit: 1-301) |
| Content of family | Peptidase family S30 contains viral polyprotein-processing peptidases. |
| History |
Identifier created: Methods Enzymol. 244:19-61 (1994)
The potyviruses cause diseases in plants, many of which are of commercial importance. The RNA genome of these viruses encodes a single large polyprotein that is processed by three viral endopeptidases to produce the mature products (Verchot-Lubicz, 2004). The peptidase are in families C4 and C6, in addition to S30. The P1 peptidase (S30.001) lies near the N-terminus of the viral polyprotein, and processes a single site at its own C-terminus. The activity of the P1 peptidase was first described by Carrington et al. (1990), and Verchot et al. (1991) began the characterisation of the enzyme. |
| Catalytic type | Serine |
| Active site residues | H216 D225 S259 |
| Active site | The His, Asp, Ser catalytic triad is typical of subclan S of clan PA. The residues of the triad are all contained in a segment of just 43 residues, an exceptionally compact arrangement (see the Alignment). |
| Activities and specificities | The P1 peptidase cotranslationally cleaves a bond at its own C-terminus. The scissile bond is -Xaa Ser-, in which Xaa is Phe or Tyr (Mavankal & Rhoads, 1991). |
| Molecular structure | The potyviral P1 peptidases are extremely varied in sequence (see the Alignment), but are assigned to a single identifier in MEROPS because they are thought to be functionally similar. No crystal structure is yet available, but indirect evidence suggests that the fold of the peptidases may be similar to that of the sindbis virus core protein (S03.001: Choi et al., 1991). |
| Clan | PA |
| Subclan | PA(S) |
| Basis of clan assignment | Active site residues for members of this family and family S1 occur in the same order in the sequence: H, D, S. |
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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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