Ribosomes can slide over and beyond "hungry" codons, resuming protein chain elongation many nucleotides downstream
Ribosomes can slide over and beyond "hungry" codons, resuming protein chain elongation many nucleotides downstream
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DOI：
10.1073/pnas.95.23.13771
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发表时间：
1998-11-10
影响因子：
11.1
通讯作者：
Lindsley, D
中科院分区：
文献类型：
--
作者：
Gallant, JA;Lindsley, D
在受到中度氨酰-tRNA限制的细胞中，停滞在“饥饿”密码子处的肽基-tRNA-核糖体复合物可以在信使RNA上滑动并在下游继续翻译。这种行为是由明确的氨基酸序列数据证明？显示了缺少饥饿密码子和特定着陆位点之间编码的旁路序列的蛋白质。着陆位点是与肽基-tRNA的反密码子同源的密码子。这种行为的效率可以高达10-20%，但随着载玻片的长度而下降。在旁路区域插入“陷阱”位点（非生产性着陆位点）降低了成功载玻片的频率，证实了核糖体-肽基-tRNA复合物通过了信使的非翻译区。这种行为似乎是相当普遍的：它可以发生在两种饥饿的密码子测试，AUA和AAG;滑动的肽基tRNA可以是任何三种测试，苯丙氨酸，酪氨酸，或亮氨酸tRNA;肽基组分可以是两个非常不同的肽序列之一;和翻译可以恢复在任何三个密码子测试。
In cells subjected to moderate aminoacyl-tRNA limitation, the peptidyl-tRNA-ribosome complex stalled at the "hungry" codon can slide well beyond it on the messenger RNA and resume translation further downstream. This behavior is proved by unequivocal amino acid sequence data? showing a protein that lacks the bypassed sequence encoded between the hungry codon and specific landing sites. The landing sites are codons cognate to the anticodon of the peptidyl-tRNA. The efficiency of this behavior can be as high as 10-20% but declines with the length of the slide. Interposition of "trap" sites (nonproductive landing sites) in the bypassed region reduces the frequency of successful slides, confirming that the ribosome-peptidyl-tRNA complex passes through the untranslated region of the message. This behavior appears to be quite general: it can occur at the two kinds of hungry codons tested, AUA and AAG; the sliding peptidyl-tRNA can be any of three species tested, phenylalanine, tyrosine, or leucine tRNA; the peptidyl component can be either of two very different peptide sequences; and translation can resume at any of the three codons tested.