白色链霉菌乙酰木聚糖酯酶基因的克隆及生物信息学分析

Cloning and Bioinformatic Analysis of Acetyl Xylan Esterase Gene from Streptomyces albus

乙酰木聚糖酯酶可以水解乙酰化木聚糖中的O-乙酰取代基团,消除该基团对木聚糖酶水解的空间阻碍作用,增强木聚糖酶对木聚糖的亲和力和降解能力。以白色链霉菌基因组为模板,利用简并PCR和TAIL-PCR扩增获得长约741 bp阅读框片段,编码247个氨基酸。生物信息学分析表明,该多肽片段具有AXE1家族蛋白保守区域;与已知的乙酰木聚糖酯酶蛋白C端区相比,相似性较高,二级和三级结构空间排布特点极为相似;初步判定该多肽片段为白色链霉菌乙酰木聚糖酯酶的C端区域。

Acetyl xylan esterase （ AXE ） can hydrolyze O-acetyl in the acetylated xylan, through which it can eliminate O-acetyl＇ s steric hindrance effects to xylanase hydrolysis, and enhance capacity of affinity and degradation to xylan. In this research, a new acetyl xylan esterase gene is cloned from Streptomyces albus, using degenerate PCR and TAIL-PCR amplified. The open reading frame consists of 741 bp and encodes 247 amino acid. Bioinformatics analysis shows that the peptide fragment has conserved regions of AXE1 family proteins. This region has similar secondary and tertiary structure with known acetyl xylan esterase protein C-terminal region, suggesting that this peptide fragment is the C-terminal region of acetyl xylan esterase from Streptomyces albus.