Periodic recurrence of methionines: fossil of gene fusion?
Periodic recurrence of methionines: fossil of gene fusion?
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蛋氨酸的周期性复发：基因融合的化石？
DOI：
10.1073/pnas.92.2.557
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发表时间：
1995
影响因子：
11.1
通讯作者：
E. Trifonov
中科院分区：
文献类型：
--
作者：
E. Kolker;E. Trifonov
正如我们最近所表明的，大约 20% 的蛋白质由均匀大小的单位组成，真核生物大约为 123 个氨基酸，原核生物大约为 152 个氨基酸。这种规律性可能通过一系列标准大小的蛋白质编码 DNA 片段（早期基因）的融合（分子重组）反映了蛋白质进化中的某些过去事件。因此，蛋氨酸作为起始残基，将标记蛋白质中与 DNA 重组位点（融合基因之间的边界）相对应的位置。蛋氨酸的这种位置偏好可能仍然作为早期蛋白质序列组织的化石存在。在这项研究中，我们解决了蛋氨酸在现代蛋白质序列中如何分布的问题。对真核序列的分析表明，正如预测的那样，甲硫氨酸残基确实优先出现在与单位大小的倍数相对应的位置处。
As we have recently shown, approximately 20% of proteins are made of uniform size units of approximately 123 aa for eukaryotes and approximately 152 aa for prokaryotes. Such regularity may reflect certain past events in protein evolution by fusion (molecular recombination) of a spectrum of standard-size protein-coding DNA segments--the early genes. Consequently, methionines, as start residues, would mark those locations in proteins that correspond to the DNA recombination sites--the borders between the fused genes. This positional preference of the methionines may still survive as a fossil of the early protein sequence organization. In this study we address the question how methionines are distributed in modern protein sequences. This analysis of eukaryotic sequences shows that methionine residues do preferentially appear at the positions corresponding to the multiples of the unit size, as predicted.