稻瘟病菌单加氧酶lpmo M1基因的克隆及生物信息学分析

多糖裂解单加氧酶（LPMO）是一类新型的可以与水解酶系协同降解纤维素、几丁质和淀粉等难溶多糖的酶。以稻瘟病菌（Magnaporthe grisea 70-15）为研究对象，采用逆转录-聚合酶链反应克隆得到多糖裂解单加氧酶基因lpmo M1，成功构建了真核表达载体pPICZαA-lpmo M1。生物信息学分析表明该基因编码区长819 bp，编码272个氨基酸，预测该基因的理论分子质量为28.85 ku，等电点为7.66；结构预测显示存在7个O-糖基化位点和16个磷酸化位点，没有N-糖基化位点。通过生物软件Vector NTI对不同来源的LPMO的同源性进行分析，结果显示稻瘟病菌LPMO M1与其他LPMO同源性最高仅为41%；系统进化分析发现稻瘟病菌（Magnaporthe grisea 70-15）的多糖裂解单加氧酶LPMO M1与黄孢原毛平革菌（Phanerochaete chrysosporium）的同类酶Gh61D亲缘关系最近。

Cloning and bioinformatic analysis of lpmo M1 from Magnaporthe oryzae

Lytic polysaccharide monooxygenases (LPMO) is a new type of enzymes that acts synergistically with hydrolase system to degrade recalcitrant polysaccharide, such as cellulose, chitin and starch. In order to study the function of LPMO from Magnaporthe grisea 70-15, lpmo M1 was cloned by RT-PCR and its eukaryotic expression vector pPICZαA-lpmo M1 was constructed. Bioinformatic analysis showed that the coding region of lpmo M1 was 819 bp, which encoded 272 amino acids, and the theory molecule weight was predicted as 28.85 ku and the soelectric point was 7.66. The structure predicted that it had 7 O-glycosylation sites and 16 phosphorylation sites, but no N-glycosylation sites. Homologous analysis by Vector NTI software indicated that LPMO M1 had a low homology with other LPMOs of the different organisms. The phylgenetic analysis results showed that LPMO M1 had a most close phylogenetic relationship with the LPMO from Phanerochaete chrysosporium.