InterPro domain: IPR039245

The peroxisomal leader peptide-processing protease (TYSND1, trypsin domain-containing 1) removes the N-terminal transit peptide from proteins containing a PTS2 target sequence [ 1 ]. The plant glyoxysomal processing protease (DEG15) performs a similar function in the glyoxysome, a specialized peroxisome. DEG15 exists as a homodimer or as a monomer; as a dimer it is a processing enzyme, as a monomer it degrades denatured proteins [ 2 ]. These peptidases are trypsin homologues and members of MEROPS family S1 and subfamily S1B. Cleavage requires a cysteine residue in P1 or P2 [ 3 ].

1. Two proteases, trypsin domain-containing 1 (Tysnd1) and peroxisomal lon protease (PsLon), cooperatively regulate fatty acid β-oxidation in peroxisomal matrix. J. Biol. Chem. 286, 44367-79
2. Dual specificities of the glyoxysomal/peroxisomal processing protease Deg15 in higher plants. Proc. Natl. Acad. Sci. U.S.A. 104, 11501-6