Endopeptidases belonging to membrane-bound hydrogenases group. These hydrogenases transfer electrons from H2 to a cytochrome that is bound to a membrane-located complex coupling electron transfer to transmembrane proton translocation. Endopeptidase HybD from E. coli is well studied in this group. Maturation of [NiFe] hydrogenases include proteolytic processing of large subunit, assembly with other subunits, and formation of the nickel metallocenter. Hydrogenase maturation endopeptidase (HybD) cleaves a short C-terminal peptide after a His or an Arg residue in the large subunit (pre-HybC) of hydrogenase 2 (hyb operon) in E. coli. This cleavage is nickel dependent. A variety of endopeptidases belong to this group that are similar in function and sequence homology. They include such proteins as HynC, HoxM, and HupD.