草鱼CNBP的分子特征及其进化分析

从草鱼(Ctenopharyngodon idella)肝肾cDNA文库中克隆到细胞核酸结合蛋白基因CNBP的完整开放阅读框序列.分析表明草鱼CNBP由163个氨基酸残基组成,含有7个保守CCHC型锌指结构、核定位信号区和RGG框,与其他鱼类的同源性很高.与人及其他脊椎动物的相比,草鱼细胞核酸结合蛋白在第3个锌指中的第5个氨基酸残基由Gly变成His,另外在第1锌指和第2锌指结构间,缺失6～14个氨基酸残基.虽然如此,适应性进化分析显示细胞核酸结合蛋白没有经历正达尔文选择(ω≤1),即这种结构的差异还不足以产生新的功能.这表明CNBP处于中性进化中.

Molecular Characterization and Evolution of Ctenopharyngodon idella CNBP

The open reading frame of cellular nucleic acid-binding protein (CNBP) was cloned from Grass Carp (Ctenopharyngodon idella) cDNA library. The coding region encodes a 163-amino acid polypeptide with the highly conserved general structural organization of seven CCHC zinc finger domains, nuclear located signal and a RGG box which was highly conserved in fish. Compared with human and other vertebrates, the fifth glycine residue at the third zinc finger domain was substituted with histidine and 6-14 amino acid r...