一种新的氨基酸序列进化距离及其应用

在选择的思想下,建立了蛋白质氨基酸序列的进化动力学方程,提出了一个新的蛋白质氨基酸序列的进化距离———选择进化距离,该距离统一了前人提出的各种氨基酸序列的进化距离;将该动力学方程转换为线性模型后,利用最小二乘法可实现模型中参数b的估计;最后,通过17个物种的细胞色素b的氨基酸序列说明了该选择进化距离的计算方法,并根据自展法比较了不同进化距离得到的物种进化树。结果表明,利用选择进化距离构建的进化树与其他几种进化距离得到的进化树的拓扑结构一致。选择进化距离为估计蛋白质氨基酸序列的进化距离提供了新方法。

A new evolutionary distance of amino acid sequences and its application

Under the theme of selection,the dynamic equation of amino acid sequences was built,and a new evolution distance(selection evolution distance) was proposed.The new evolution distance’s properties were analyzed,and it contained other distances of protein sequence.The dynamic equation could be transformed into a linear regression model,then the parameter b was estimated by the least square method.The amino acid sequences of cytochrome b in 17 species were taken as an example to illustrate the new evolution distance,and the different evolution trees based on different evolution distances were compared by the bootstrap.The results showed that the topology of the evolution tree based on selection evolution distance was consistent with that based on other distances.The new distance provide a new method to estimate evolution distance of amino acid sequences.