small GTPase EC:3.6.5.2 IMR:0000288 IPR:001806 Ras superfamily The RAS superfamily of GTP (guanosine triphosphate) hydrolysis-coupled signal transduction relay proteins can be subclassified into RAS, RHO, RAB, and ARF families, as well as the closely related G alpha family. The members of each family can, in turn, be arranged into evolutionarily conserved branches. These groupings reflect structural, biochemical, and functional conservation. molecule_role small G-protein small GTP-binding protein GTP-binding protein GTPase