3.6.5.2 GTP + H2O = GDP + phosphate a family of about 50 enzymes with a molecular mass of 21 kDa that are distantly related to the alpha-subunit of heterotrimeric G-protein GTPase, EC 3.6.1.46, they are involved in cell-growth regulation, Ras subfamily, membrane vesicle traffic and uncoating, Rab and ARF subfamilies, nuclear protein import, Ran subfamily, and organization of the cytoskeleton, Rho and Rac subfamilies 657767 3.6.5.2 GTP + H2O = GDP + phosphate A family of about 50 enzymes with a molecular mass of 21 kDa that are distantly related to the alpha-subunit of heterotrimeric G-protein GTPase, EC 3.6.1.46. They are involved in cell-growth regulation, Ras subfamily, membrane vesicle traffic and uncoating, Rab and ARF subfamilies, nuclear protein import, Ran subfamily, and organization of the cytoskeleton, Rho and Rac subfamilies - 3.6.5.2 GTP + H2O = GDP + phosphate mechanism, biphasic reaction 657726