[Cloning and nucleotide sequence determination of the fus gene coding for the elongation factor G of Thermus thermophilus HB8].

A clone with the Thermus thermophilus HB8 fus gene coding for elongation factor G has been identified in a genomic library in plasmid pBR 322 by hybridization with labeled oligonucleotide 19 bases that are complementary in length to the 3'-end of the T. thermophilus fus gene. The fragment with the fus gene was recloned into the pTZ 18R plasmid. A restriction map of this fragment has been made. A set of short overlapping fragments of the fus gene has been obtained by nucleotide sequence unspecific linearization of the plasmid and by the restriction fragment subcloning into M13 mp18 and mp19 vectors. The nucleotide sequence of the fus gene was determined by the dideoxy chain termination method. Fus gene codes the elongation factor G 690 amino acids in length (Mr = 76756 Da). The amino acid sequence of EF-G from T. thermophilus has a 59.7% homology with that of E. coli and a 29.0% homology with EF-2 of rat liver.