Young R, Bremer H
Biochem J. 1976 Nov 15;160(2):185-94. doi: 10.1042/bj1600185.
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.
通过评估新生多肽和成熟多肽的放射性标记动力学,确定了三种不同生长速率(μ)下大肠杆菌B/r的肽链延伸速率:快速生长的细胞(μ等于1.3和2.0次倍增/小时)为17个氨基酸/秒,缓慢生长的细胞(μ等于0.67次倍增/小时)为12个氨基酸/秒。这些结果与在该菌株中以及在这些生长条件下新诱导的β-半乳糖苷酶信使翻译中发现的肽链延伸速率对生长速率的依赖性一致[Dalbow & Young (1975) Biochem. J. 150, 13 - 20]。结合之前在这些生长速率下观察到的核糖体效率[Dennis & Bremer (1974) J. Mol. Biol. 84, 407 - 422],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。