CTP can replace GTP in reactions catalyzed by eukaryotic peptide elongation factor 1

In several reactions catalyzed by highly purified peptide elongation factor 1 from rabbit reticulocytes, GTP may be fully replaced by CTP but not by ATP or UTP. This holds true for the factor-dependent binding of aminoacyl-tRNA to ribosomes, GTPase activity, GTP-dependent autophosphorylation of the factor protein and binding of cholesteryl 14-methylhexadecanoate by the factor.