Family C27

Family

Summary Holotypes Alignment Genomes Literature Architecture

Summary for family C27

Family type peptidase	C27.001 - rubella virus peptidase (Rubella virus), MEROPS Accession MER0002110 (peptidase unit: 1110-1275)
Content of family	Peptidase 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 type	Cysteine
Active site residues	C1152 H1273
Active site	The 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 specificities	The 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).
Inhibitors	High 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 structure	The 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).
Clan	unassigned
Basis of clan assignment	Active 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 C27	Sequences:	1
	Identifiers:	1
	Identifiers with PDB entries:	0
Downloadable files	Sequence library (FastA format)

Other databases	INTERPRO	IPR008738
	PFAM	PF05407

Peptidases and Homologues	MEROPS ID	Structure
rubella virus peptidase	C27.001	-
Family C27 unassigned peptidases	unassigned	-