利用真菌纤维素结合域(CBD)保守性序列进行草菇木聚糖酶cDNA的克隆

木聚糖是植物细胞壁的主要组分,它是木糖以β1 ,4 木糖苷键形成主链,乙酰基,阿拉伯糖基等为附链组成的复合多聚糖.木聚糖酶可以降解木聚糖主链,在木聚糖的生物降解中起着非常重要的作用1 ] .根据木聚糖酶催化域(catalyticdomain ,CD)氨基酸序列的相似性,木聚糖酶可分为两个家

Cloning and Sequencing of Xylanase cDNA from Volvariella volvacea Using Conserved Sequences in Cellulose-Binding Domain

Cellulose binding domains (CBDs) are present in the majority of fungal cellulases and hemicellulases. Based on the conserved region of CBDs, degenerate primers were designed and used to amplify the 5′ end cDNA fragment of xylanase from Volvariella volvacea by 5′ RACE. Gene specific primer was then designed based on extreme region of 5′ end cDNA fragment and used to amplify the full length cDNA of xylanase. The cDNA of xyn 1 was 1 287 bp in length, including 3′ and 5′ non coding region. The xyn 1 cDNA contained an ORF of 1101 bp encoding 367 amino acids, in which there was a putative signal peptide with 19 amino acids. Alignment of the deduced amino acid sequence of xyn 1 with other xylanases showed that the homology with family 10 xylanases from Agaricus bisporus xyl1,Aspergillus sojae xyn1, Aspergillus kawachii xynA, Fusarium oxysporum f.sp xyl3 was 64%,55%,52%,55%, respectively.