紫花苜蓿几丁质酶ClassⅢ基因克隆及生物信息学分析

本文根据截叶苜蓿(Medicago truc atula)几丁质酶ClassⅢ基因(GenBank:AY294484.1)的全长序列设计引物,通过RT-PCR的方法得到紫花苜蓿(Medicago sative)几丁质酶ClassⅢ的核酸序列,命名为MsChiⅢ,在NCBI中的登录号为FJ872918。利用生物信息学软件分析MsChiⅢ,预测氨基酸序列的等电点、二级结构和三级结构,并构建系统发育树。结果显示该核酸序列全长为953bp,包括完整的开放阅读框,编码301个氨基酸,等电点为8.212。该序列所编码的蛋白属于几丁质酶18家族的内切酶,分布于细胞间隙,并含有几丁质酶18家族的特征序列——LGDVDFDIE,并预测MschiⅢ可能是一种具有几丁质酶和溶菌酶的双功能酶。

Cloning and Bioinformatics Analysis of Chintnase Class Ⅲ Gene in Medicago sative

The eDNA of chitinase Class Ⅲ gene (GenBank accession:AY294484.1) from Medicago sative was cloned by RT-PCR,with primers designed according to the sequence of chitinase Class Ⅲ of Medicago trucatula,It was named as MsChi Ⅲ,and its GenBank accession number is FJ872918.The isoelectric point of amino acid sequence,secondary and three-dimersional structures of MsChi Ⅲ were analysed by bioinformatics software,and the homologue tree of chitinase Ⅲ was established.The result showed that the sequence consisted of 953 bp and had an full open reading frame,which encoded a polypeptide of 301 amino acid residues.The estimated PI of Class Ⅲ chitinase of Medicago satire was 8.212.The protein coded by this sequence as incision enzyme belong to chitinase family 18,dispersed in intercellular space,and the amino acid sequence included special sequence of chitinase family 18,with an amino acid sequence of LGDVDFDIE.The effects of chitinase Class Ⅲ would include chitinase and lysozyme.