POTENTIAL SECONDARY STRUCTURE AT THE TRANSLATIONAL START DOMAIN OF EUKARYOTIC AND PROKARYOTIC MESSENGER-RNAS
POTENTIAL SECONDARY STRUCTURE AT THE TRANSLATIONAL START DOMAIN OF EUKARYOTIC AND PROKARYOTIC MESSENGER-RNAS
复制标题
DOI：
10.1016/0300-9084(94)90120-1
复制
发表时间：
1994-01-01
期刊：
影响因子：
3.9
通讯作者：
LOUIS, BG
中科院分区：
文献类型：
--
作者：
GANOZA, MC;LOUIS, BG
为了确定翻译起始位点内保守的潜在二级结构，我们使用能够描述这些特征的程序研究了来自不同物种的mRNA序列。首先对290种真核mRNA编码序列中71个碱基的潜在二级结构进行了检测，并与原核mRNA序列中290个类似分析的区域进行了比较（核酸研究（1987）15,345-360）。在这两组序列中，通常发现启动密码子处于开放电位结构中，而编码区则是一个以近周期性间隔为特征的密集区域。序列的随机化消除了观察到的模式，表明mRNA的结构可能决定了这些差异。对三组长度大致相等的真核和原核mrna进行了分析，发现它们在起始密码子前保留了一个开放的未配对非编码区5'。在所有分析的序列中，超过80%的起始密码子没有潜在的二级结构。这些数据，以及对限制起始密码子进入核糖体起始复合物的突变体的研究表明，原核和真核mRNA起始位点都必须在没有潜在二级结构的情况下发生，才能有效起始。真核生物mRNA序列分析的一个显著差异是起始密码子附近的编码区形成的高倾向。二级结构。某些翻译缺陷突变体表现出这些二级结构的形成受损，这表明真核mrna起始密码子附近的编码区结构可能是一个重要的，迄今尚未被研究的起始决定因素。我们认为，对于所有研究的基因，二级结构在编码区和非编码区之间的过渡可能是起始的重要决定因素。
In order to identify conserved potential secondary structures within translational start sites, mRNA sequences derived from different species were studied with programs able to depict such features. The potential secondary structure of 71 bases around the initiator AUG or AUGs in the coding sequences of 290 eukaryotic mRNAs was first examined and compared to 290 similarly analyzed regions derived from prokaryotic mRNA sequences (Nucleic Acids Res (1987) 15, 345-360). In both sets of sequences the initiator codon was often found to be in an open potential structure whereas a denser region characterized by nearly-periodic spacings defined the coding regions. Randomization of the sequences obliterated the observed patterns suggesting that the structure of the mRNA may determine these differences. Three sets of eukaryotic and prokaryotic mRNAs of approximately equal length were analyzed and found to preserve an open unpaired non-coding region 5' to the start codon. The start codon was found free of potential secondary structure in over 80% of all the sequences analyzed. These data, and study of mutants that restrict the accessibility of the start codon to the ribosomal initiation complex, suggest that both the prokaryotic and eukaryotic mRNA start sites must occur free of potential secondary structure for efficient initiation. A striking difference of the eukaryotic mRNA sequences analyzed was the high propensity of the coding region vicinal to the start codon to form. secondary structures. Certain translation-defective mutants exhibit impaired formation of these secondary structures suggesting that the structure of the coding regions adjacent to the start codons of eukaryotic mRNAs may be an important, thus far unexamined, determinant of initiation. We propose that, for all genes studied, the transition in secondary structure between the coding and non-coding regions may be an important determinant of initiation.