Syntheses of elongation factors Tu and G are under stringent control in Escherichia coli.

We have compared the synthesis of the elongation factors Tu and G at 30 and 36.5 degrees in three strains of Escherichia coli: NF314 (rel+valS+), NF536 (rel+valSts), and NF537 (rel-valSts). At the elevated temperature, the latter two strains continue to grow but suffer a partial deprivation of valyl-tRNA. As a consequence, the syntheses of stable RNA, Tu, and G are decreased in NF536; the syntheses of stable RNA, Tu, and G are increased in NF537. These results indicate that the syntheses of Tu and G are directly or indirectly under the influence of the rel gene.