|PROSITE documentation PDOC00548 [for PROSITE entry PS00631]|
Cytosol aminopeptidase is a eukaryotic cytosolic zinc-dependent exopeptidase that catalyzes the removal of unsubstituted amino-acid residues from the N-terminus of proteins. This enzyme is often known as leucine aminopeptidase (EC 220.127.116.11) (LAP) but has been shown  to be identical with prolyl aminopeptidase (EC 18.104.22.168). Cytosol aminopeptidase is a hexamer of identical chains, each of which binds two zinc ions.
Cytosol aminopeptidase is highly similar to Escherichia coli pepA, a manganese dependent aminopeptidase. Residues involved in zinc ion-binding  in the mammalian enzyme are absolutely conserved in pepA where they presumably bind manganese. Most bacterial species contain a pepA-type enzyme.
As a signature pattern for these enzymes, we selected a perfectly conserved octapeptide which contains two residues involved in binding metal ions: an aspartate and a glutamate.Note:
April 2006 / Pattern revised.
PROSITE method (with tools and information) covered by this documentation:
|1||Authors||Matsushima M. Takahashi T. Ichinose M. Miki K. Kurokawa K. Takahashi K.|
|Title||Structural and immunological evidence for the identity of prolyl aminopeptidase with leucyl aminopeptidase.|
|Source||Biochem. Biophys. Res. Commun. 178:1459-1464(1991).|
|2||Authors||Burley S.K. David P.R. Sweet R.M. Taylor A. Lipscomb W.N.|
|Title||Structure determination and refinement of bovine lens leucine aminopeptidase and its complex with bestatin.|
|Source||J. Mol. Biol. 224:113-140(1992).|
|3||Authors||Rawlings N.D. Barrett A.J.|
|Title||Evolutionary families of metallopeptidases.|
|Source||Methods Enzymol. 248:183-228(1995).|