巴西蕉多酚氧化酶的基因克隆及序列分析

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巴西蕉多酚氧化酶的基因克隆及序列分析

作者：杨昭 何春兰 黄佳佳 黄国平 李芬芳 袁德保 来源：《安徽农学通报》2016年第11期

摘 要：基于香蕉基因组的信息，利用电子克隆方法获得巴西蕉PPO基因，结合RT-PCR验证，并通过生物信息学软件对巴西蕉PPO进行序列分析。结果表明，成功获得编码巴西蕉PPO的新基因，序列长度为1 767bp，编码588个氨基酸（GenBank登录号：KF900300.1）。巴西蕉PPO基因与禾本科植物PPO基因有着较高的同源性，相似度在82%～85%，与蔷薇科鸡麻亲缘关系最近。巴西蕉PPO最有可能存在于叶绿体中，不具有信号肽，含有一个长度为47个氨基酸的叶绿体转运肽。巴西蕉PPO蛋白属于酪氨酸酶基因家族蛋白，具有酪氨酸酶超级家族、PPO1_DWL和PPO1_KFDV3个保守结构域。巴西蕉PPO分子量为65.6 KDa，等电点为6.32，为亲水性蛋白质。巴西蕉PPO二级结构中无规则卷曲占的比例最高为57.31%，成功预测得到巴西蕉PPO的三级结构模型。

关键词：巴西蕉；多酚氧化酶；基因组；电子克隆

中图分类号 Q785 文献标识码 A 文章编号 1007-7731（2016）11-0023-06 Cloning and Sequencing of the Brazilian Banana Polyphenol Oxidase Yang Zhao1 et al.

（1Guangdong Food and Drug Vocational College，Guangzhou 510520，China）

Abstract：Based on the information about the banana genome，PPO gene of brazilian banana was cloned in silico，and validated by RT-PCR，and analyzed by bioinformatics software.New gene encoding brazilian banana PPO was successfully obtained，with sequence length of 1767bp，encoded a protein of 588 amino acids （GenBank accession number：KF900300.1）.Brazilian banana PPO gene has a high homology with gramineae plant PPO gene，and their similarity was between 82%～85%.Furthermore，brazilian banana PPO gene had the closest relationship with the rhodotypos scandens of rosaceae PPO gene.Brazilian banana PPO was most likely to exist in the chloroplast，without a signal peptide，but containing a chloroplast transit peptide with length of 47 amino acids.Brazilian banana PPO protein belonged to tyrosinase protein gene family，with three conserved domains of tyrosine enzyme superfamily，PPO1_DWL and PPO1_KFDV.Brazilian banana PPO with molecular weight of 65.6 KDa and an isoelectric point of 6.32，was a hydrophilic protein.The secondary structure of brazilian banana PPO in the proportion of random coil accounted for up to 57.31%.And the tertiary structure of brazilian banana PPO was predicted successfully. Key words：Brazilian banana；Polyphenol oxidase；Genome；In silico cloning