全α类蛋白质超家族保守模体特征的分析

Analysis of Conservative Motif Features of the Protein Superfamilies in All α Class

选取了全α类中序列一致性小于等于40%和25%的四个有代表性的超家族,并从中提取序列模体和结构模体,分析了其结构和功能特征的差异.结果表明,细胞色素C超家族和EF手超家族中已知功能的模体类型相对单一,而类同源域超家族和翼螺旋DNA结合域超家族中序列模体类型较多,但是主要以HTH和wHTH两种结构模体为主.进一步对模体的相对位置进行统计分析和比较,发现无论是已知功能的模体还是基于统计学方法识别的模体,它们相对于序列N端和C端的分布均呈现一定的规律性.这些特征和规律将对蛋白质超家族的识别以及结构域的研究提供有力的帮助.

Four representative protein suprefamilies are chosen from all α protein class. The sequence and structure motifs are extracted from the sequences with identity less than 40% and 25%. By discussing their different function features, the results indicate that the known function motifs are relatively single in Cytochrome C superfamily and EF-hand superfamily. Many types of sequence motifs responding to structural motif are HTH and wHTH in Homeodomain-Like and the ＂ Winged helix＂ DNA-binding domain superfamily,respectively. By calculating and comparing motif position ,some important regularities of the position distribution are obtained. The distance between motifs and C （or N） terminal of sequence is conservative for motif whether from function or statistic significance. These correlated regularities will have some important help for identifying different protein superfamilies and the protein domains.