Family C33

Family

Summary Holotypes Alignment Tree Genomes Structure Literature Architecture

Summary for family C33

Family type peptidase	C33.001 - equine arteritis virus Nsp2-type cysteine peptidase (equine arteritis virus), MEROPS Accession MER0001422 (peptidase unit: 259-340)
Content of family	Peptidase family C33 contains a viral polyprotein-processing endopeptidase.
History	Identifier created: Perspect.Drug Discov.Des. 6:1-11 (1996)
Catalytic type	Cysteine
Active site residues	C270 H332
Active site	Catalytic Cys and His residues have been identified by mutagenesis (Snijder et al., 1995) (see the Alignment).
Activities and specificities	There is indirect evidence that Nsp2-type cysteine peptidase (C33.001) cleaves between two Gly residues (Ziebuhr et al., 2004). Cleavage is rapid in cis and very slow in trans (Snijder et al., 1995).
Molecular structure
Clan	CA
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	Nsp2-type cysteine peptidase is the most C-terminal of three peptidase domains in the N-terminal 500 residues of the arterivirus ORF1a protein. It assists the Nsp4 main peptidase (S32.001) in the proteolytic maturation of the replicase proteins through cleavage of the Nsp2Nsp3 site, regulating the processing of the ORF1a protein downstream of Nsp2 (Snijder et al., 1996; Wassenaar et al., 1997). In the presence of Nsp2, Nsp4 will cleave the Nsp4Nsp5 site at its C-terminus. However, in its absence, cleavage instead occurs at the Nsp5Nsp6 and Nsp6Nsp7 sites (Wassenaar et al., 1997).
Reviews	Gorbalenya et al. (2004)
Statistics for family C33	Sequences:	14
	Identifiers:	1
	Identifiers with PDB entries:	1
Downloadable files	Sequence library (FastA format)
	Sequence alignment (FastA format)
	Phylogenetic tree (Newick format)

Other databases	INTERPRO	IPR008743
	PFAM	PF05412

Peptidases and Homologues	MEROPS ID	Structure
equine arteritis virus Nsp2-type cysteine peptidase	C33.001	Yes
Family C33 unassigned peptidases	unassigned	-