黑曲霉XZ-3S木聚糖酶Xyn ZF-1基因克隆和序列分析

Cloning and sequence analysis of the gene encoding xylanase Xyn ZF-1 from Aspergillus niger XZ-3S

摘要: 利用RT-PCR技术从黑曲霉XZ-3S中扩增并克隆了木聚糖酶（Xyn ZF-1）基因的cDNA片段,测序结果表明,Xyn ZF-1基因核苷酸序列阅读框全长678bp,编码225个氨基酸,推测分子量为24.06ku,等电点为5.20。以XZ-3S基因组DNA为模板扩增Xyn ZF-1的DNA序列,该序列仅存在一个内含子,长度为68bp。成熟肽基因推导的氨基酸序列与其他微生物来源的木聚糖酶一级结构进行比较,同源性最高达到了89.47%。系统进化树分析该酶属于G/11族糖基水解酶。又进一步对Xyn ZF-1二级结构进行了分析,并通过SWISS-MODEL预测了该酶的三维结构。

Abstract: The cDNA of xylanase (Xyn ZF-1) gene was amplified from the Aspergillus niger XZ-3S total RNA by RT-PCR. The result showed that Xyn ZF-1 was 678bp in size and encoded 225 amino acids. The molecular weight and theoretical isoelectric point was 24.06ku and 5.20, respectively. The DNA of Xyn ZF-1 gene was amplified from the Aspergillus niger XZ-3S genmic DNA by PCR. The result confirmed that there was only one intron with the 68bp in length.The homology analysis of amino acid sequence shared 89.47% in base sequence with other microbial xylanase primary structure.Phylogenetic analysis showed that the enzyme belongd to glycosyl hydrolase family G/11. Besides, the secondary structure of Xyn ZF-1 was analysed, and three-dimensional structure of Xyn ZF-1 was predicted by SWISS-MODEL.