The structure of cytochrome c and the rates of molecular evolution.
The structure of cytochrome c and the rates of molecular evolution.
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DOI：
10.1007/bf01659392
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发表时间：
1971-01-01
期刊：
影响因子：
--
通讯作者：
Dickerson, R, E.
中科院分区：
文献类型：
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作者：
Dickerson, R, E.
铁细胞色素的X-射线结构分析显示了疏水性和芳香性侧链、赖氨酸和甘氨酸的进化保守性的原因，这已经从30多个物种的氨基酸序列的比较中观察到。它还表明，分子表面的一部分的负性特征是保守的，尽管单个酸性侧链不是，并且正电荷位于从内部通向表面的两个疏水性“通道”周围。细胞色素表面特征不寻常的进化保守性的原因可能是分子与另外两个大分子复合物的相互作用，其还原酶和氧化酶。这种表面结构的保守性也解释了细胞色素序列的变化速度相对于类似大小的球蛋白和酶而言相对较慢的原因。蛋白质的进化速度是基因组中突变的发生率，这种突变的发生率是由氨基酸序列中的随机变化在功能蛋白质中是可容忍的概率所改变的。纤维蛋白肽、球蛋白、细胞色素c和几种酶的变化率被解释为蛋白质的生物学作用。
The x-ray structure analysis of ferricytochromecshows the reasons for the evolutionary conservatism of hydrophobic and aromatic side chains, lysines, and glycines, which had been observed from comparisons of amino acid sequences from over 30 species. It also shows that the negative character of one portion of the molecular surface is conserved, even though individual acidic side chains are not, and that positive charges are localized around two hydrophobic “channels” leading from the interior to the surface.The reason for the unusual evolutionary conservation of surface features in cytochromescis probably the interaction of the molecule with two other large macromolecular complexes, its reductase and oxidase. This conservation of surface structure also explains the relatively slow rate of change of cytochromecsequences in comparison with the globins and enzymes of similar size.The rate of evolution of a protein is the rate of occurrence of mutations in the genome modified by the probability that a random change in amino acid sequence will be tolerable in a functioning protein. The observed rates of change in fibrinopeptides, the globins, cytochromec, and several enzymes are interpreted in terms of the proteins' biological roles.