大肠杆菌Top10甘露醇-1-磷酸脱氢酶基因克隆及生物信息学分析

根据细菌中存在的甘露醇-1-磷酸脱氢酶（mannitol-1-phosphate dehydrogenase，mtlD）的基因序列，采用PCR扩增的方法从大肠杆菌（Escherichia coli）Top10中克隆到了mt／D基因（Acession numeber：EU433565）。mtlD开放阅读框为1149bp，编码含有382个氨基酸残基，分子量为41．2kD的蛋白，预测等电点为5．37。mtlD含有38个碱性氨基酸，50个酸性氨基酸，158个疏水氨基酸及72个极性氨基酸。二级结构预测表明该蛋白含约60．47％的α-螺旋、4．71％的β-转角、10．73％的延伸链和20．48％的不规则卷曲。亲疏水性分析显示，mtlD是亲水性蛋白。亚细胞定位分析表明mtlD主要定位于细胞质中。序列分析表明大肠杆菌Top10 mtlD基因与大肠杆菌W3350、大肠杆菌DEC12a和盐生盐杆菌（Halobacterium salinarum）的mtlD基因同源性分别为99％、97％和93％。大肠杆菌Top10mtlD基因的克隆及生物信息学分析为今后对mtlD的进一步深入研究奠定了基础。

Molecular Cloning and Bioinformatic Analysis of Mannitol-1-phosphate Dehydrogenase Gene in Escherichia coli Top10

The mannitol-1-phosphate dehydrogenase gene(mtlD) was cloned from Escherichia coli Top10 by PCR,with primers designed according to public mtlD sequences.The open reading frame of mtlD gene has 1 149 bp in length and encoded a protein of 382 amino acid residues.The estimated molecular weight and isoelectric points of the putative protein were 41.2 kD and 5.37,respectively.Components of amino acids encoded mtlD contained 38 basic amino acids,50 acidic amino acids,158 hydrophobic amino acids and 72 polar amino...