深海沉积物微生物宏基因组文库中IMP环水解酶的筛选及基因克隆  

Screening and Cloning of IMP Cyclohydrolase from a Metagenomic Cosmid Library of a Deep-sea Sediment Sample

作　　者：陈兴麟[1] 赵晶[2] 徐宪忠[1] 曾润颖[1] 

机构地区：[1]国家海洋局第三海洋研究所,海洋生物遗传资源重点实验室,厦门361005 [2]厦门大学海洋与环境学院,海洋技术与工程系,厦门361005

出　　处：《应用与环境生物学报》2011年第6期855-859,共5页Chinese Journal of Applied and Environmental Biology

基　　金：中国大洋协会项目(No.DYXM-115-02-2-04)资助~~

摘　　要：为了解嘌呤合成途径的关键酶——IMP环水解酶的多样性,从深海沉积物样品中提取总DNA构建Cosmid宏基因组文库,从中筛选出一个具有IMP环水解酶活性的克隆(CAIMP1).通过基因步移的方法从CAIMP1的约35 kb的插入片段中扩增出长度为1 599 bp的完整的IMP环水解酶基因,该基因包含MGS和AICARFT_IMPCHas两个保守结构域.活性检测结果表明CAIMP1克隆的发酵液上清具有较强的IMP环水解酶活性.该酶与数据库中收录的IMP环水解酶的氨基酸序列同源性较低,系统发育分析也表明该酶与其它参照序列亲缘关系较远,表明该序列可能为一个新的IMP环水解酶基因.IMP cyclohydrolase is a key enzyme in the purine synthesis pathway. A clone （CAIMP1） producing IMP cyclohydrolase activity was isolated from a metagenomic library which was constructed from metagenomic DNA of a deep-sea sediment sample. The gene coding for the IMP cyclohydrolase with the size of 1 599 bp was subcloned from the 35 kb inserted fragment of CAIMP1 by gene walking. Two conserved domains, MGS and AICARFT_IMPCHas, was found in the gene. The CAIMP1 exhibited high activity towards 5-formaminoimidazole-4-carboxamide ribonucleotide （FAICAR）. The alignment and phylogenetic analysis of amino acid sequence of the CAIMP1 IMP cyclohydrolase showed that it had low homology with other referenced sequences in GenBank, indicating that it might be a new sequence. Fig 5, Tab 3, Ref 17

关 键 词：深海沉积物 宏基因组文库 IMP环水解酶 保守结构域 

分 类 号：Q93[生物学—微生物学]