Increased Functional Activity of Elongation Factor G with G16V Mutation in the GTP-Binding Domain

K. A. Martemyanov¹, A. Liljas², and A. T. Gudkov^1*

¹Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region, 142292 Russia; fax: (095) 924-0493; E-mail: gudkov@sun.ipr.serpukhov.su

²Department of Molecular Biophysics, Lund University, Box 124, S-211 00 Lund, Sweden

^* To whom correspondence should be addressed.

Received November 27, 1997; Revision received December 11, 1997

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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 of the factor G from E. coli. The mutated protein with an uncleavable GTP analog also has an increased affinity to the ribosomes.

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KEY WORDS: translation, elongation factor G, mutagenesis

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