Nilsson G, Belasco J G, Cohen S N, von Gabain A
Proc Natl Acad Sci U S A. 1987 Jul;84(14):4890-4. doi: 10.1073/pnas.84.14.4890.
Translational stop codons were introduced at various locations in the protein-coding regions of the monocistronic bla and ompA gene transcripts of Escherichia coli, and the decay characteristics of the upstream and downstream mRNA segments were analyzed. Premature termination of translation at codon position 26 reduced the stability of both the translated and ribosome-free segments of bla mRNA, whereas release of ribosomes just 30 codons further downstream resulted in normal stability for both segments. Normal stability of an untranslated bla gene mRNA segment required its linkage to a ribosome-bound segment of bla gene mRNA. These findings indicate that depriving an mRNA segment of ribosomes does not necessarily render it more susceptible to degradation. However, premature termination of translation at a location that allows ribosomes to traverse only a short segment of bla mRNA can lead to destabilization of the entire transcript.
在大肠杆菌单顺反子bla和ompA基因转录本的蛋白质编码区的不同位置引入翻译终止密码子，并分析上游和下游mRNA片段的衰变特征。在密码子位置26处提前终止翻译降低了bla mRNA翻译片段和无核糖体片段的稳定性，而仅在下游30个密码子处释放核糖体则导致两个片段都具有正常的稳定性。未翻译的bla基因mRNA片段的正常稳定性要求其与bla基因mRNA的核糖体结合片段相连。这些发现表明，剥夺mRNA片段的核糖体不一定会使其更容易降解。然而，在一个允许核糖体仅穿过bla mRNA短片段的位置提前终止翻译会导致整个转录本的不稳定。
