Family C11

Family

Summary Holotypes Alignment Tree Genomes Structure Literature

C11A

Summary Holotypes Genomes Literature

C11B

Summary Holotypes Genomes Literature

Summary for family C11

NamePeptidase family C11 (clostripain family)
Family type peptidaseC11.001 - clostripain (Clostridium histolyticum), MEROPS Accession MER0000831 (peptidase unit: 51-526)
Content of familyPeptidase family C11 contains the cysteine endopeptidase clostripain and its homologues.
History Identifier created: Biochem.J. 290:205-218 (1993)
Partial purification of the secreted endopeptidase of Clostridium histolyticum, which we now know as clostripain (C11.001), was reported by Kocholaty et al. (1938), and the specifcity of the enzyme for hydrolysis of arginyl bonds was recognised by Ogle & Tytell (1953).
Catalytic typeCysteine
Active siteThe catalytic residues are His176 and Cys231 (see the Alignment).
Activities and specificitiesClostripain is selective for hydrolysis of arginyl bonds. It requires calcium ions for activity, as well as a reducing environment.
InhibitorsTos-Lys-CH2Cl reacts covalently with the active site, and is an effective active-site titrant. Z-Phe-Arg-CHN2 irreversibly and rapidly inactivate clostripain (Zumbrunn et al., 1988), and leupeptin is a potent reversible inhibitor (Kembhavi et al., 1991). E-64, a potent inhibitor of many peptidases in clan CA, gives only reversible inhibition that is attributable to the presence of an arginine-like sidechain in the compound.
Molecular structureClostripain is synthesized as a proprotein, and activation requires loss of a 23-residue propeptide and autolytic removal of an internal nonapeptide to produce a heterodimer consisting of a 131-residue light chain and a 336-residue heavy chain. The heavy chain contains the catalytic dyad. The active site sequence motif -HG-(Xaa)n-AC- conserved in family C11 places it in clan CD (Chen et al., 1998). No tertiary structure is available for clostripain at the time of writing.
ClanCD
Basis of clan assignmentPredicted active site residues for members of this family and family C14 occur in the same order in the sequence: H, C.
Distribution of family Bacteria details  
Archaea details  
Protozoa details  
Fungi -  
Plants details  
Animals details  
Viruses details  
Biological functionsClostripain may well contribute to the nutrition of Clostridium sp. by breaking down proteins extracellularly.
Pharmaceutical and biotech relevanceClostripain has been used in peptide synthesis (GŁnther et al., 2000).
ReviewsUllmann & Bordusa (2004)
Statistics for family C11Sequences:464
Identifiers:4
Identifiers with PDB entries:1
Downloadable files Sequence library (FastA format)
Sequence alignment (FastA format)
Phylogenetic tree (Newick format)
Subfamily C11A
Name Peptidase subfamily C11A
Subfamily type peptidase C11.001 - clostripain (Clostridium histolyticum), MEROPS Accession MER0000831 (peptidase unit: 51-526)
Active site residues H176 C231 
Statistics Sequences: 18
Identifiers: 2
Identifiers with PDB entries: 1
Other databases INTERPRO IPR005077
PFAM PF03415
Downloadable files Sequence library [FastA format]
Sequence alignment [FastA format]
Phylogenetic tree [Newick format]
Peptidases and Homologues MEROPS ID Structure
clostripainC11.001-
PmC11 peptidase (Parabacteroides merdae)C11.003Yes
subfamily C11A non-peptidase homologuesnon-peptidase homologue-
subfamily C11A unassigned peptidasesunassigned-
Subfamily C11B
Name Peptidase subfamily C11B
Subfamily type peptidase C11.002 - PNT1 peptidase ({Trypanosoma brucei}) (Trypanosoma brucei), MEROPS Accession MER1152299 (peptidase unit: 65-232)
Active site residues H99 C136 
Statistics Sequences: 9
Identifiers: 1
Identifiers with PDB entries: 0
Other databases INTERPRO IPR005077
PFAM PF03415
Downloadable files Sequence library [FastA format]
Sequence alignment [FastA format]
Phylogenetic tree [Newick format]
Peptidases and Homologues MEROPS ID Structure
PNT1 peptidase (Trypanosoma brucei)C11.002-
subfamily C11B non-peptidase homologuesnon-peptidase homologue-
subfamily C11B unassigned peptidasesunassigned-
Peptidases not assigned to subfamily
Peptidases and Homologues MEROPS ID Structure
family C11 non-peptidase homologuesnon-peptidase homologue-
family C11 unassigned peptidasesunassigned-