Putative [NiFe] hydrogenase-specific C-terminal protease. Sequence comparison shows similarity to hydrogenase specific C-terminal endopeptidases, also called Hydrogen Maturation Proteases (H2MP). Maturation of [FeNi] hydrogenases includes formation of the nickel metallocenter, proteolytic processing and assembly with other subunits. Hydrogenase maturation endopeptidases are responsible for the proteolytic processing, liberating a short C-terminal peptide by cleaving after a His or an Arg residue, e.g., HycI (E. coli) is involved in processing of HypE (the large subunit of hydrogenases 3). This cleavage is nickel dependent.