Presumably involved in the processing and regular turnover of intracellular proteins. Release of an N-terminal amino acid, Xaa-|-Yaa-, in which Xaa is preferably Leu, but may be other amino acids including Pro although not Arg or Lys, and Yaa may be Pro. Amino acid amides and methyl esters are also readily hydrolyzed, but rates on arylamides are exceedingly low. Release of N-terminal proline from a peptide. Binds 2 Mg(2+) ions per subunit. Homohexamer (dimer of homotrimers). Induced by wounding (PubMed:8234334, PubMed:15231736). Induced by methyl jasmonate (PubMed:15231736). Belongs to the peptidase M17 family.