Family S30


Summary Holotypes Alignment Tree Genomes Structure Literature Architecture

Summary for family S30

Family type peptidaseS30.001 - potyvirus P1 peptidase (plum pox virus), MEROPS Accession MER0000297 (peptidase unit: 1-301)
Content of familyPeptidase 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 typeSerine
Active site residuesH216 D225 S259 
Active siteThe 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 specificitiesThe P1 peptidase cotranslationally cleaves a bond at its own C-terminus. The scissile bond is -XaaSer-, in which Xaa is Phe or Tyr (Mavankal & Rhoads, 1991).
Molecular structureThe 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).
Basis of clan assignmentActive site residues for members of this family and family S1 occur in the same order in the sequence: H, D, S.
Distribution of family Bacteria -  
Archaea -  
Protozoa -  
Fungi -  
Plants -  
Animals -  
Viruses details  
Biological functionsThe role of the P1 peptidase in the biology of the potyviruses has been explored, showing that the proteolytic separation of the P1 protein is essential for viral infectivity (Verchot & Carrington, 1995; Verchot & Carrington, 1995).
Statistics for family S30Sequences:97
Identifiers with PDB entries:0
Downloadable files Sequence library (FastA format)
Sequence alignment (FastA format)
Phylogenetic tree (Newick format)
Other databases INTERPRO IPR001254
PFAM PF01577
Peptidases and Homologues MEROPS ID Structure
potyvirus P1 peptidaseS30.001-
clover yellow vein potyvirus-type P1 peptidaseS30.002-
Family S30 non-peptidase homologuesnon-peptidase homologue-
Family S30 unassigned peptidasesunassigned-