小麦β-酮脂酰CoA合成酶基因KCS的克隆与酵母表达  

Cloning and Yeast Expression of 3-ketoacyl-coenzyme Synthase(KCS)Gene in Wheat(Triticum aestivum L.)

作　　者：夏凌峰[1] 史雪[1] 杨昊虹 李春莲[1] 王中华[1] 权力[1] 

机构地区：[1]西北农林科技大学农学院/旱区作物逆境生物学国家重点实验室,陕西杨凌712100

出　　处：《麦类作物学报》2016年第9期1121-1129,共9页Journal of Triticeae Crops

基　　金：国家自然科学基金项目(31471568);陕西省重点科技创新团队项目(2014KCT-25);西北农林科技大学唐仲英育种项目;西北农林科技大学基本科研业务费一般项目(QN2013006)

摘　　要：超长链脂肪酸是生物体内众多重要物质的合成底物。KCS基因编码β-酮脂酰CoA合成酶,该酶具有底物特异性,参与超长链脂肪酸延伸的缩合反应,是超长链脂肪酸合成的限速步骤。为了探究小麦KCS基因在超长链脂肪酸合成中的功能,采用同源克隆的方法从小麦(Triticum aestivum L.)中克隆出KCS基因后,利用生物信息学对其编码序列进行分析,并在酿酒酵母(Saccharomyces cerevisiae)中对其进行真核表达。结果表明,小麦TaKCS6基因的开放阅读框为1 287bp,编码428个氨基酸残基。结构域预测结果显示,TaKCS6蛋白含有III型聚酮合酶脂肪酸延伸酶和C末端3-酰基ACP合酶III结构域,属于KCSs蛋白家族。序列比对分析结果显示,TaKCS6氨基酸序列与拟南芥及其他植物的KCS6氨基酸序列在两个功能结构域上和活性位点保守。酵母表达结果显示,TaKCS6基因编码的蛋白参与C24以上超长链脂肪酸的延伸。Very-long-chain fatty acids （VLCFAs） are the synthetic substrates for many important substances in the living body. The KCS gene encodes β-ketoacyl CoA synthase, a rate-limiting enzyme in the synthesis of VLCFAs, catalyzing the condensation reaction of VLCFAs elongation process. In order to identify the function of KCS gene in biosynthesis of VLCFAs, the homologous cloning strategy was used to clone KCS gene from wheat（Triticurn aestivum L. ）, the coding sequence was analysed by a series of bioinformatics software and expressed in yeast （Saccharomyees cerevisiae）. The result showed that the open reading frame of TaKCS6gene is 1 287 bp, which encodes 428 amino acid residues. Functional domain analysis predicted that TaKCS6 protein belonging to KCSs protein family, contains FAEI_CUT1_RppA and ACP_syn_III_C domains. The amino acid sequences of TaKCS6, AtKCS6 and KCS6 from other plants are conservative in two functional domains and activity sites. Yeast expression of TaKCS6 showed that encoded protein is involved in the elongation of VLCFAs more than 24 carbons.

关 键 词：普通小麦 超长链脂肪酸 KCS基因 酵母表达 

分 类 号：S512.1[农业科学—作物学] S330