Cysteine protease that cleaves specifically after arginine or lysine residues. Localizes to RAB11-positive recycling endosomes. Expressed in the mammalian blood stage form and insect procyclic form (at protein level). RNAi-mediated knockdown causes no defect in the growth of the bloodstream stage form (PubMed:16507595). Knockout has no defect in the growth of the procyclic form (PubMed:16507595). Simultaneous RNAi-mediated knockdown of MCA2, MCA3 and MCA5 in the bloodstream stage form causes a growth arrest resulting from a block prior to cytokinesis; DNA replication and mitosis are normal (PubMed:16507595). Has no effect on VSG protein recycling (PubMed:16507595). Triple knockout of MCA2, MCA3 and MCA5 in the bloodstream form causes an initial slower growth rate in vitro which reaches wild-type levels after several weeks of culture (PubMed:16507595). Triple knockouts have a normal growth rate and virulence in infected mice (PubMed:16507595). Belongs to the peptidase C14B family.