Function
Involved in the maturation of [NiFe] hydrogenases. Required for nickel insertion into the metal center of the hydrogenase (PubMed:7601092, PubMed:8756471). Exhibits a low intrinsic GTPase activity, which is essential for nickel insertion (PubMed:7601092, PubMed:21544686, PubMed:27951644). In the presence of GDP, nickel, but not zinc, is transferred from the HypB GTPase domain (G-domain) to HypA (PubMed:23899293, PubMed:27951644).