DUF3663 |
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| PFAM accession number: | PF12404 |
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| Interpro abstract (IPR008330): | Over 70 metallopeptidase families have been identified to date. In these enzymes a divalent cation which is usually zinc, but may be cobalt, manganese or copper, activates the water molecule. The metal ion is held in place by amino acid ligands, usually three in number. In some families of co-catalytic metallopeptidases, two metal ions are observed in crystal structures ligated by five amino acids, with one amino acid ligating both metal ions. The known metal ligands are His, Glu, Asp or Lys. At least one other residue is required for catalysis, which may play an electrophillic role. Many metalloproteases contain an HEXXH motif, which has been shown in crystallographic studies to form part of the metal-binding site [ (PUBMED:7674922) ]. The HEXXH motif is relatively common, but can be more stringently defined for metalloproteases as 'abXHEbbHbc', where 'a' is most often valine or threonine and forms part of the S1' subsite in thermolysin and neprilysin, 'b' is an uncharged residue, and 'c' a hydrophobic residue. Proline is never found in this site, possibly because it would break the helical structure adopted by this motif in metalloproteases [ (PUBMED:7674922) ]. This family represents the peptidase B group of leucyl aminopeptidases, which are restricted to the gammaproteobacteria. They contain a C-terminal aminopeptidase catalytic domain and an N-terminal domain of unknown function. They are zinc-dependent exopeptidases ( EC 3.4.11.1 ) and belong to MEROPS peptidase family M17 (leucyl aminopeptidase family, clan MF). They selectively release N-terminal amino acid residues from polypeptides and proteins and are involved in the processing, catabolism and degradation of intracellular proteins [ (PUBMED:8703509) (PUBMED:1555602) (PUBMED:2395881) ]. Leucyl aminopeptidase forms a homohexamer containing two trimers stacked on top of one another [ (PUBMED:2395881) ]. Each monomer binds two zinc ions. The zinc-binding and catalytic sites are located within the C-terminal catalytic domain [ (PUBMED:2395881) ]. The same catalytic aminopeptidase domain is found in the other M17 peptidases IPR011356 . These two groups of aminopeptidases differ by their N-terminal domains. The N-terminal domain in members of IPR011356 has been implicated in DNA binding [ (PUBMED:10449417) (PUBMED:10970742) ] and it is not associated with members of this family which have a different N-terminal domain and therefore are not expected to bind DNA or be involved in transcriptional regulation. In addition, there are related proteins with the same catalytic domain and unique N-terminal sequences unrelated to any of the two N-terminal domains discussed above. For additional information please see [ (PUBMED:8439290) (PUBMED:7674922) (PUBMED:10852868) (PUBMED:8506345) ]. |
| GO process: | proteolysis (GO:0006508) |
| GO component: | cytoplasm (GO:0005737) |
| GO function: | manganese ion binding (GO:0030145), metalloaminopeptidase activity (GO:0070006) |
This is a PFAM domain. For full annotation and more information, please see the PFAM entry DUF3663