Family C27


Summary Holotypes Alignment Genomes Literature

Summary for family C27

Family type peptidaseC27.001 - rubella virus peptidase (Rubella virus), MEROPS Accession MER0002110 (peptidase unit: 1110-1275)
Content of familyPeptidase family C27 contains the non-structural polyprotein processing endopeptidase from the rubella virus.
History Identifier created: Perspect.Drug Discov.Des. 6:1-11 (1996)
Rubella virus is a positive-strand RNA virus related to togaviruses such as Sindbis virus. The viral genome contains two polyprotein genes, one for structural proteins and a larger one for non-structural proteins. The structural polyprotein is processed by the host signalase (S26.010). The discovery that the endopeptidase is metal-dependent has led to the proposal that it is a metallopeptidase rather than a cysteine peptidase (Liu et al., 2000).
Catalytic typeCysteine
Active site residuesC1152 H1273 
Active siteThe catalytic dyad, Cys1151 and His1272, has been identified by site-directed mutagenesis (Marr et al., 1994; Chen et al., 1996). However, His1272 has also been shown to be a zinc ligand (Liu et al., 2000).
Activities and specificitiesThe endopeptidase processes the non-structural polyprotein at one site only, Gly1300Gly1301 (Chen et al., 1996). Cleavage occurs both in cis and in trans and divalent cations such as Zn2+ enhance activity (Liu et al., 1998).
InhibitorsHigh concentrations of the metal chelator phosphoramidon (1 mM) and the metallopeptidase inhibitor captopril (1 mM) have been shown to inhibit (Liu et al., 2000).
Molecular structureThe limits of the endopeptidase within the polyprotein have been defined only approximately. The metal ligands have been determined by site-directed mutagenesis to be Cys1174, Cys1177, Cys1226 and His1272 (Liu et al., 2000).
Basis of clan assignmentActive site residues for members of this family and family C1 occur in the same order in the sequence: C, H.
Distribution of family Bacteria -  
Archaea -  
Protozoa -  
Fungi -  
Plants -  
Animals -  
Viruses details  
Biological functions
Statistics for family C27Sequences:1
Identifiers with PDB entries:0
Downloadable files Sequence library (FastA format)
Peptidases and Homologues MEROPS ID Structure
rubella virus peptidaseC27.001-
family C27 unassigned peptidasesunassigned-