Peptidase M17, leucine aminopeptidase/peptidase B (IPR011356)

Short name: Leucine_aapep/pepB

Overlapping homologous superfamilies


Family relationships


The majority of members of this family are zinc-dependent exopeptidases belonging to MEROPS peptidase family M17 (leucyl aminopeptidase, clan MF).

Leucyl aminopeptidase (LAP; EC: selectively release N-terminal amino acid residues from polypeptides and proteins; in general they are involved in the processing, catabolism and degradation of intracellular proteins [PMID: 8703509, PMID: 1555602, PMID: 2395881]. Leucyl aminopeptidase forms a homohexamer containing two trimers stacked on top of one another [PMID: 2395881]. Each monomer binds two zinc ions. The zinc-binding and catalytic sites are located within the C-terminal catalytic domain [PMID: 2395881]. Leucine aminopeptidase has been shown to be identical with prolyl aminopeptidase (EC: in mammals [PMID: 1908238].

Interestingly, members of this group are also implicated in transcriptional regulation and are thought to combine catalytic and regulatory properties [PMID: 10970742]. The N-terminal domain of these proteins has been shown in Escherichia coli PepA to function as a DNA-binding protein in Xer site-specific recombination and in transcriptional control of the carAB operon [PMID: 10449417, PMID: 10970742]. It is not well conserved and in some members can be found only by PSI-BLAST (after 4-6 iterations). It is not clear if the DNA binding function is preserved in all or even in most of the members.

For additional information please see [PMID: 2670557, PMID: 8439290, PMID: 7674922, PMID: 8506345].

GO terms

Biological Process

GO:0019538 protein metabolic process

Molecular Function

GO:0004177 aminopeptidase activity
GO:0030145 manganese ion binding
GO:0008235 metalloexopeptidase activity

Cellular Component

GO:0005737 cytoplasm

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.