来源于角毛壳茵的木聚糖酶xyn24基因克隆及特性

摘要

The full length cDNA encoding xylanase {xyn24) gene from Chaetomium cupreum was cloned based on the sequence (GenBank Accn; DV547992) in C. Cupreum cDNA library. Primers were designed and synthesized according to the sequence of the xyn24 gene. The open reading frame was 690 bp encoding 229 amino acids. The protein molecular weight was 24.7 kD and its theoretical isoelectric point was 7.83. The sequence analysis indicated that xyn24 gene contains 2 ex-ons and 1 intron. BlastP analysis reveals that the amino acid sequences of xyn24 genes from some fungal species share low similarity. The xyn24 from C. Cupreum shares the highest similarity with that from Scytalidium thermophilum, and the similarity is 78%. The cDNA and deduced amino acid sequence of xyn24 gene were accepted by CeneBank (Accession numbers; EF026978, DQ886937).%利用Blastx将角毛壳茵(Chaetomium cupreum)ESTs与GenBank的Nr数据库进行相似性比对,获得1条编码木聚糖酶基因的全长cDNA序列的EST( GenBank Accn:DV547992),依据该序列设计并合成引物,以角毛壳茵基因组为模板进行PCR扩增,获得角毛壳菌xyn24的全长DNA序列,该DNA序列全长875 bp,由1个内含子和2个外显子组成；cDNA序列全长690 bp,编码229个氨基酸,蛋白质的相对分子质量为24700,理论等电点为7.83.经BlastP分析,xyn24基因的氨基酸序列的保守性不高,与嗜热革节孢菌(Scytalidium thermophilum AB114442)中的木聚糖酶基因的同源性最高,为78％,故推测该基因可能是1条新发现的木聚糖酶家族基因,该序列已收录于GenBank,登录号为:DQ886937,EF026978.