M-Ras is a member of the small GTPase superfamily under the Ras family, which also includes Rap1, Rap2, R-Ras, and R-Ras2 (TC21). This protein spans a length of 209 residues. Its N-terminal amino acid sequence shares 60-75% identity with that in the Ras protein while its effector region is identical with that in Ras. M-Ras shares a similar structure with H-Ras and Rap2A with the exception of its switch 1 conformation when bound to guanosine 5'- (beta,gamma-imido)triphosphate (Gpp (NH)p). Of the two states M-Ras can switch between, M-Ras is predominantly found in its state 1 conformation, which does not bind Ras effectors.