Family M76


Summary Holotypes Alignment Tree Genomes Literature H-seq M-seq Architecture

Summary for family M76

Family type peptidaseM76.001 - Atp23 peptidase (animal-type) (Homo sapiens), MEROPS Accession MER0060642 (peptidase unit: 1-288)
Content of familyPeptidase family M76 contains endopeptidases.
History Identifier created: MEROPS 7.7 (23 January 2007)
Peptidase family M76 contains the mitochondrial processing protein, Atp23 peptidase (M76.001). This processes the Atp6 subunit of the F1FO-ATP synthase, which is the complex that catalyses the synthesis of ATP from ADP and phosphate. This complex is found in the mitochondrion and is assembled from subunits that are nuclear and mitochondrially encoded.
Catalytic typeMetallo
Active site residuesH167 E168 H171 
Active siteAtp23 peptidase contains an HEXXH zinc-binding motif. His167 and His171 are assumed to be metal-binding ligands and Glu168 a catalytic residue. Mutation of these residues results in unprocessed Atp6 protein (Osman et al., 2006).
Activities and specificitiesAtp23 protein processes the mitochondrially-encoded, subunit Atp6 of the F1FO-ATP synthase (Osman et al., 2006).
Molecular structureNo structure is yet available, but the presence of the HEXXH motif places the family in clan MA.
Distribution of family Bacteria details  
Archaea -  
Protozoa details  
Fungi -  
Plants details  
Animals details  
Viruses -  
Biological functionsIn Saccharomyces cerevisiae the Atp23 peptidase is encoded by the nuclear YNR020c gene and imported into the mitochondrial lumen. In addition to its processing activities, the Atp23 protein also acts as a chaperone for the inclusion of the Atp6 protein within the F1FO-ATP synthase (Osman et al., 2006).
Statistics for family M76Sequences:831
Identifiers with PDB entries:0
Downloadable files Sequence library (FastA format)
Sequence alignment (FastA format)
Phylogenetic tree (Newick format)
Other databases INTERPRO IPR019165
PFAM PF09768
Peptidases and Homologues MEROPS ID Structure
Atp23 peptidase (animal-type)M76.001-
ATP23 peptidase (Saccharomyces cerevisiae-type)M76.002-
PF14_0396 g.p. (Plasmodium falciparum)M76.A01-
ATP23 peptidase (Schizosaccharomyces pombe-type)M76.A02-
DDB_G0270738 g.p. (Dictyostelium discoideum)M76.A03-
Family M76 non-peptidase homologuesnon-peptidase homologue-
Family M76 unassigned peptidasesunassigned-