链霉菌Streptomyces sp. S9木聚糖酶基因xynBS9的克隆表达及性质分析  

Cloning,Expression and Characterization of a Xylanase Gene,xynBS9,from Streptomyces sp.S9

作　　者：姚国玉[1,2] 李宁[2] 石鹏君[2] 陈强[1] 姚斌[2] 

机构地区：[1]兰州大学生命科学学院生物化学与分子生物学研究所,兰州730000 [2]中国农业科学院饲料研究所农业部饲料生物技术重点实验室,北京100081

出　　处：《中国农业科技导报》2009年第4期64-70,共7页Journal of Agricultural Science and Technology

基　　金：国家863计划项目(2007AA100601);国家科技攻关项目(2006BAD12B05-03)资助

摘　　要：通过设计简并引物和构建基因组文库的方法从链霉菌Streptomycessp.S9中克隆得到-βl,4-木聚糖酶基因xynBS9。该基因全长1 023 bp,编码340个氨基酸。将不带原基因信号肽编码序列的xynBS9以正确阅读框架克隆到表达载体pET-22b(+)上,并在大肠杆菌BL2 l(DE3)中诱导表达。重组蛋白经硫酸铵分级沉淀和疏水柱纯化后达到电泳纯。酶学性质分析表明,重组木聚糖酶最适温度为60℃,最适pH为6.5,在碱性条件下具有良好的稳定性。The gene xynBS9 encoding β-1, 4-xylanase was cloned from Streptomyces sp. S9 by designing degenerate primers and screening from a genomic library of Streptomyces sp. S9. The xynBS9 gene was 1 023 bp in length and encoded by a protein with 340 amino acids. The xynBS9 gene without signal peptide was inserted into the expression vector of pET-22b （ ＋ ） and transformed into Escherichia coli BL21 （ DE3 ） to express. The recombinant protein was purified by ammonium sulfate precipitant and hydrophobic interaction chromatography. Characteristic analysis indicated that the optimum temperature and pH value for the recombined xylanase were 60℃ and 6.5, respectively, and XynBS9 showed an extreme stability under alkaline condition.

关 键 词：链霉菌 木聚糖酶 xynBS9基因 原核表达 

分 类 号：Q786[生物学—分子生物学]