TRANSLATION FRAMING CODE AND FRAME-MONITORING MECHANISM AS SUGGESTED BY THE ANALYSIS OF MESSENGER-RNA AND 16 S RIBOSOMAL-RNA NUCLEOTIDE-SEQUENCES
TRANSLATION FRAMING CODE AND FRAME-MONITORING MECHANISM AS SUGGESTED BY THE ANALYSIS OF MESSENGER-RNA AND 16 S RIBOSOMAL-RNA NUCLEOTIDE-SEQUENCES
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DOI：
10.1016/0022-2836(87)90241-5
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发表时间：
1987-04-20
影响因子：
5.6
通讯作者：
TRIFONOV, EN
中科院分区：
文献类型：
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作者：
TRIFONOV, EN
蛋白质编码序列以通用的三碱基周期性模式（G-非-G-N）n的形式携带额外的信息，其表达为在mRNA中密码子的第一位置中对鸟嘌呤的强烈偏好和在第二位置中缺乏鸟嘌呤。这种周期性在起始密码子之后立即出现，并沿着mRNA一直保持到终止三联体，在那里它突然消失。分析了翻译过程中核糖体滑动的已知情况（漏移码，框外基因融合）。在网站的滑移的G周期图案被发现是中断。它在滑动点的下游重新出现，出现在与新平移坐标系相对应的新坐标系中。这表明mRNA中的（G-非-G-N）n模式可能负责在翻译过程中监测正确的阅读框架。在大肠杆菌16 SrRNA序列中发现了几个具有互补C-周期结构的位点。其中只有三个暴露于核糖体小亚基表面的各种相互作用：（517）gcCagCagCcgC，（1395）caCacCgcC和（1531）auCacCucC。基于核糖体RNA中G-周期mRNA与C-周期位点的弱互补性，提出了一种框架监控机制的模型。该模型得到了以下事实的有力支持，即来自核苷酸序列分析的16 S rRNA中的假设框架监测位点也是已知实际参与或涉及rRNA-mRNA相互作用的唯一位点。
Protein coding sequences carry an additional message in the form of a universal three-base periodical pattern (G-non-G-N)n, which is expressed as a strong preference for guanines in the first positions of the codons in mRNA and lack of guanines in the second positions. This periodicity appears immediately after the initiation codon and is maintained along the mRNA as far as the termination triplet, where it disappears abruptly. Known cases of ribosome slippage during translation (leaky frameshifts, out-of-frame gene fusion) are analyzed. At the sites of the slippage the G-periodical pattern is found to be interrupted. It reappears downstream from the slippage sites, in a new frame that corresponds to the new translation frame. This suggests that the (G-non-G-N)n pattern in the mRNA may be responsible for monitoring the correct reading frame during translation. Several sites with complementary C-periodical structure are found in the Escherichia coli 16 S rRNA sequence. Only three of them are exposed to various interactions at the surface of the small ribosomal subunit: (517)gcCagCagCcgC, (1395) caCacCgcC and (1531) auCacCucC. A model of a frame-monitoring mechanism is suggested based on the weak complementarity of G-periodical mRNA to the C-periodical sites in the ribosomal RNA. The model is strongly supported by the fact that the hypothetical frame-monitoring sites in the 16 S rRNA that are derived from the nucleotide sequence analysis are also the only sites known to be actually involved or implicated in rRNA-mRNA interactions.