【摘要】 目的:用2株新分离鉴定的细菌克隆与最近源种(Bacillus halodurans C-125)木聚糖酶基因的同源序列,并对其进行序列分析。方法:根据已发表的近源种(C-125)的保守区序列设计引物,扩增出与其同源的木聚糖酶基因,进而用pQE31载体对该基因进行表达。同时对表达蛋白的三维空间结构进行网络模拟分析,对蛋白同源性进行比对分析。结果:克隆的木聚糖酶基因片段分别为1284bp和1236bp,而且该基因也成功表达;该蛋白是(α/α)6折叠构象,与C-125三者同属于一个分支上。结论:通过分析、表达蛋白编码外切-1,4-β-木聚糖酶,属于M家族。这该新分离菌株木聚糖酶的研究和应用提供了重要线索。更多还原

【Abstract】 Objective:To clone the xylanase gene from two isolated Bacillus halodurans strains and analyse the sequences.Methods: According to conserved sequence analysis of the nearest species(C-125), a pair of primers were used to amplify and express the genes. And the three-dimentional structure of the two XynM protein was analysed by ExPASy. Meanwhile, phylogenetic tree of Xyn proteins was also made. Results:The BhXJU-1 xynM (1284bp) and BhXJU-80 (1236bp) xynM geneswere amplified and successfully expressed. And the proteins were (α/α)6 fold. Sequence homology analysis of amino acid showed that the two proteins shared high homology (99%) compared with different species of Bacillus halodurans and they belonged to the same branch of phylogenetic tree. Conclusion:The two proteins encoded endo-1, 4-β-xylanase were new members of family M of glycosyl hydrolases. This offered an important clue for the study of the xylanase product of the XJU-1 and XJU-80 species.更多还原