Hydrolases;
Acting on peptide bonds (peptidases);
Aminopeptidases
Reaction(IUBMB)
The enzyme cleaves the Pro36-Pro37 bond of cysteine desulfurase (EC 2.8.1.7) removing three amino acid residues (Tyr-Ser-Pro) from the N-terminus after cleavage by mitochondrial processing peptidase.
Comment
Icp55 removes the destabilizing N-terminal amino acid residues that are left after cleavage by the mitochondrial processing peptidase, leading to the stabilisation of the substrate. The enzyme can remove single amino acids or a short peptide, as in the case of cysteine desulfurase (EC 2.8.1.7), where three amino acids are removed.