Molecular cloning of a rho family gene of Entamoeba histolytica

Abstract

An Entamoeba histolytica gene (Eh rhol) was cloned that encodes a putative low-molecular-mass GTP-binding protein, most similar to the ras homologue rho. The Eh rhol open reading frame was 208 amino acids long and encoded a 23-kDa protein similar to Saccharomyces cerevisiae RHO1-RH04 and CDC42 and human rhoA, racl. and G25K, gene products. This similarity was greatest at the NH₂ terminus of Eh rhol where two GTP-binding sites and a possible effector site were conserved. A cysteine residue at the COOH terminus of Eh rhol was followed by eight hydrophobic amino acids rather than the three hydrophobic amino acids present in other ras family proteins.