糖基转移酶基因双敲除对依博素生物合成的影响  

The Effects of Glycosyltransferase Genes Double Disruption in Ebosin Biosynthesis

作　　者：白利平[1] 谢鸿观[1] 单俊杰[2] 姜蓉[1] 张洋[1] 郭连宏[1] 李元[1] 

机构地区：[1]中国医学科学院北京协和医学院医药生物技术研究所卫生部抗生素生物工程重点实验室,北京100050 [2]军事医学科学院毒物药物研究所,北京100850

出　　处：《中国生物工程杂志》2009年第6期46-51,共6页China Biotechnology

基　　金：国家自然科学基金重点资助项目(30530830)

摘　　要：以往研究已确定链霉菌胞外多糖依博素的生物合成基因簇(ste),ste15和ste22分别编码葡萄糖糖基转移酶和鼠李糖糖基转移酶。现通过基因同源重组双交换,在ste15基因缺失突变株Streptomyces sp.139(ste15-)基础上,再进行ste22基因阻断,经Southern杂交验证,得到了ste15和ste22双基因缺失突变株Streptomycessp.139(ste15-ste22-),并对该菌株进行了基因互补研究。双基因缺失株产生的胞外多糖与依博素相比,葡萄糖与鼠李糖含量明显降低,分子量下降,生物活性明显变弱。基因互补株产生的胞外多糖中葡萄糖与鼠李糖含量基本恢复至依博素水平,生物活性也显著提高。因此,进一步阐明了ste15和ste22基因参与了依博素生物合成中葡萄糖和鼠李糖重复单元序列的形成过程,在依博素的生物合成中起重要作用,变株产生的依博素新衍生物体内外生物学活性正在深入研究中。The biosynthesis cluster （ste） of a novel exololysaccharide called Ebosin producing by Streptomyces had been identified previously, that ste15 and ste22 encode glucosyhransferase and rhamnosyltransferase respectively. The ste22 gene was disrupted with a double crossover via homologous recombination in the mutant strain Streptomyces sp. 139 （ste15^-）. The mutant strain Streptomyces sp. 139 （ste15^- ste22^-） was identified by Southern blot and gene complementation also performed. Compared with Ebosin, the glucose and rhamnose of EPS15-22m produced by Streptomyces sp. 139 （ste15^ ste22^-） were reduced obviously and the Mp and the antagonist activity for IL-1 R decreased. Glucose, rhamnose and the antagonist activity for IL-1R were recovered in EPS15-22c producing by the gene complemented strain. It elucidated that genes ste15 and ste22 play essential roles in the formation of repeating units of sugars during Ebosin biosynthesis. The activities of Ebosin new derivatives produced by the mutants need to be studied further both in vitro and in vivo.

关 键 词：葡葡萄糖糖基转移酶基因 鼠李糖糖基转移酶基因 链霉菌 基因双敲除 依博素新衍生物 

分 类 号：Q789[生物学—分子生物学]