Aminopeptidase which cleaves preprotein intermediates that carry destabilizing N-ter amino acid residues after the mitochondrial processing peptidase (MPP) cleavage site and is thus critical for stabilization of the mitochondrial proteome. The enzyme cleaves the 36-Pro-Pro-37 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. Binds 2 manganese ions per subunit. Has the same dual localization (mitochondrion and nucleus) as one of its substrate, NFS1. Present with 5080 molecules/cell in log phase SD medium. Belongs to the peptidase M24B family.