InterPro domain: IPR000223

This group of serine peptidases belong to MEROPS peptidase family S26 (signal peptidase I family, clan SF), subfamily S26A.

At least 3 eubacterial leader peptidases are known: murein prelipoproteinpeptidase, which cleaves the leader peptide from a component of thebacterial outer membrane; type IV prepilin leader peptidase; and the serine-dependent leader peptidase 1, which has the more general role of cleavingthe leader peptide from a variety of secreted proteins and proteins directedto the periplasm and periplasmic membrane [ 1 ]. Leader peptidase 1 is similar to the eukaryotic signal peptidase, although the bacterial protein is monomeric, while the eukaryotic protein is multimeric [ 2 ].

Mitochondria contain a similar two-subunit serine protease that removesleader peptides from nuclear- and mitochondrial-encoded proteins, whichlocalise in the inner mitochondrial space [ 2 ]. The catalytic residues of a number of these peptides have been identified as a serine/lysine dyad [ 2 ].

1. Families of serine peptidases. Meth. Enzymol. 244, 19-61