Hughes D
Department of Molecular Biology, Biomedical Centre, Uppsala, Sweden.
Mol Microbiol. 1991 Mar;5(3):623-30. doi: 10.1111/j.1365-2958.1991.tb00733.x.
Mutations in Salmonella typhimurium encoding error-prone EF-Tu (tufA8, tufB103) enhance translational error levels and also cause a reduced growth rate. The relative changes in error level and growth rate are inversely related and dependent on the status of the two tuf genes. Possible causes of the reduced growth rate were investigated. Several important parameters with the potential to alter growth rate (the EF-Tu-ribosome interaction, the in vivo elongation rate and the processivity of translation), are all relatively unaffected by the tuf mutations. The small reduction in processivity observed in some strains is not quantitatively related to the growth rate reduction. Instead, the error-enhancing mutations are associated with a large reduction in the specific activity of a test protein, beta-galactosidase, suggesting by inference that the reduced growth rate is a consequence of the synthesis of error-containing proteins.
鼠伤寒沙门氏菌中编码易出错的延伸因子 Tu（tufA8、tufB103）的突变会提高翻译错误水平，同时也会导致生长速率降低。错误水平和生长速率的相对变化呈负相关，并且取决于两个tuf基因的状态。对生长速率降低的可能原因进行了研究。几个有可能改变生长速率的重要参数（延伸因子 Tu 与核糖体的相互作用、体内延伸速率和翻译的持续合成能力）均相对不受tuf突变的影响。在一些菌株中观察到的持续合成能力的小幅降低与生长速率降低在数量上并无关联。相反，错误增强突变与测试蛋白β-半乳糖苷酶的比活性大幅降低有关，由此推断生长速率降低是合成含错误蛋白的结果。
