By evaluating the kinetics of radioactive labelling of nascent and finished polypeptides, the peptide-chain elongation rate for Escherichia coli B/r at three different growth rates (mu) was determined to be 17 amino acids/s for the fast-growing cells (mu equals 1.3 and 2.0 doublings/h) and 12 amino acids/s for slow-growing cells (mu equals 0.67 doublings/h). The results agree with the growth-rate-dependence of the rate of peptide-chain elongation found for the translation of newly induced beta-galactosidase messenger in this strain and under these conditions of growth [Dalbow & Young (1975) Biochem. J. 150, 13-20]. Together with the previously observed ribosome efficiency at these growth rates [Dennis & Bremer (1974) J. Mol. Biol. 84, 407-422] the results indicate that the fraction of ribosomes engaged in protein synthesis is about 0.8 at all three growth rates.
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机译：通过评估新生多肽和最终多肽的放射性标记动力学，在三种不同的生长速率（μ）下，大肠杆菌B / r的肽链伸长率被确定为快速增长的细胞（μ/ s）为17个氨基酸/秒。等于1.3和2.0倍/小时）和12个氨基酸/秒的慢速生长细胞（mu等于0.67倍/小时）。结果与在该菌株中和在这些生长条件下新诱导的β-半乳糖苷酶信使的翻译所发现的肽链延伸速率的生长速率依赖性一致[Dalbow＆Young（1975）Biochem。 J. 150，13-20]。连同先前观察到的在这些生长速率下的核糖体效率[Dennis＆Bremer（1974）J.生物学84，407-422]的结果表明，在所有三种生长速率下，参与蛋白质合成的核糖体比例约为0.8。
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