Deana A, Reiss C
Institut Jacques Monod, CNRS-Université Paris VII, France.
C R Acad Sci III. 1993 Jul;316(7):628-32.
The ompA gene of E. coli was silently mutated by the substitution of nine codons located towards the end of the gene, by synonymous codons expected to be translated more slowly. At 37 degrees C in vivo the life-time of the ompA messenger RNA (mRNA) is reduced from 4.5 min (w.t.) to 3.8 min (silent mutant). The amount of mRNA of the silent mutant is only 30% of that observed for the w.t. gene. These variations are thought to be due to the uncoupling of transcription from translation, and a lesser protection of the mRNA towards RNase digestion by ribosomes, resulting from a lesser density of the ribosome traffic on the mutated polysome.
大肠杆菌的ompA基因通过位于基因末端的九个密码子被预期翻译速度更慢的同义密码子替换而发生沉默突变。在37摄氏度的体内环境中，ompA信使核糖核酸（mRNA）的寿命从4.5分钟（野生型）缩短至3.8分钟（沉默突变体）。沉默突变体的mRNA量仅为野生型基因所观察到量的30%。这些变化被认为是由于转录与翻译的解偶联，以及核糖体对mRNA的核糖核酸酶消化保护作用减弱，这是由突变多聚核糖体上核糖体移动密度降低导致的。
