Increased functional activity of elongation factor G with G16V mutation inthe GTP-binding domain

Oligonucleotide-directed mutagenesis was used to obtain elongation factor G from Thermus thermophilus with the G16V mutation in its GTP-binding domain . Functional studies of the mutated protein and elongation factor G from E, coli were carried out. The data revealed that the G16V mutant retains high thermostability, has an increased ribosome-dependent GTPase activity, and its translation activity in cell-free translation system is equal to that o f the factor G from E. coli. The mutated protein with an uncleavable GTP an alog also has an increased affinity to the ribosomes.