分枝犁头霉WL511热稳定α-半乳糖苷酶基因克隆及序列分析  

Cloning and Sequence Analysis of a Thermostable α-Galactosidase Gene of Absidia ramose WL511

作　　者：李荷[1,2] 游娟[1] 顾取良[1] 刘玉焕[2] 

机构地区：[1]广东药学院基础学院,广东广州510006 [2]中山大学生命科学学院,广东广州510275

出　　处：《食品与生物技术学报》2011年第1期124-130,共7页Journal of Food Science and Biotechnology

基　　金：国家自然科学基金项目(30570055);广东省科技攻关项目(2009B020313005);广东省自然科学基金博士启动基金项目(9451022401003873);广东药学院博士启动项目(2006JCX06)

摘　　要：构建并筛选耐热分枝犁头霉cDNA文库获得639 bp热稳定α-半乳糖苷酶基因片段,并以5′-RACE和3-′RACE技术获得上下游片段1817 bp和1092 bp,拼接得α-半乳糖苷酶全长序列2228 bp,其完整开放读码框为2142 bp,编码713个氨基酸,G+C含量43%;产物预测等电点5.2,预测相对分子质量81000。该基因(GenBank No.DQ234280)属α-半乳糖苷酶36家族,与其他来源的α-半乳糖苷酶基因同源性较低,与链霉菌Streptomyces avermitilis MA-4680的α-半乳糖苷酶同源性最高为38%。A DNA clone containing α-galactosidase gene fragment （639 bp） was isolated from the constructed cDNA library of Absidia ramose WL511. The 5 ＇-RACE and 3＇-RACE techniques confirmed this gene＇s upstream and downstream sequences （1817 bp, 1092 bp） Sequences analysis revealed that this gene with the full length of 2228 bp made a complete open reading frame of 2142 bp encoding a polypeptide of 713 amino acid residues with predicted molecular mass of 81 kDa and predicted pI of 5. 2. This gene （GenBank No. DQ234280）, belonging to α- galactosidase 36 family, showed a very low homology with other sources of α-galactosidase genes. The most similarity was 38 % between the α-galactosidases of Streptomyces averrnitilis MA-4680 and A. ramose WL511.

关 键 词：热稳定α-半乳糖苷酶基因 克隆 序列分析 

分 类 号：Q78[生物学—分子生物学]