玉米肉桂醇脱氢酶基因ZmCAD4的克隆和生物信息学分析

肉桂醇脱氢酶(CAD)是木质素生物合成途径的限速酶。对玉米B73基因组数据库和NCBI数据库中注释为玉米B73 CAD的基因进行挖掘和筛选，对其中1条玉米肉桂醇脱氢酶基因ZmCAD4克隆，并进行生物信息学分析。结果表明，共筛选到12条玉米CAD基因，克隆的ZmCAD4基因编码区全长1 104 bp，编码367个氨基酸。ZmCAD4蛋白含有典型的CAD1结构域、Zn结合位点和NADP结合位点，不含有跨膜结构域和信号肽，为非分泌蛋白，亚细胞定位预测定位在细胞质中。蛋白三级结构预测与拟南芥AtCAD5蛋白相似，相似度达到73.80%。系统进化分析表明，ZmCAD4与芒草、高粱等禾本科植物亲缘关系最近。

Cloning and Bioinformatic Analysis of ZmCAD4 Gene from Maize

Cinnamyl alcohol dehydrogenase(CAD) is a rate-limiting enzyme in lignin biosynthesis pathway. The genes annotated CAD in the genome data of Zea Mays B73 and NCBI database were searched out, and a cinnamyl alcohol dehydrogenase gene ZmCAD4 was cloned and bioinformatically analyzed. A total of twelve ZmCAD genes were obtained. The length of the coding region of ZmCAD4 was 1 104 bp, encoding 367 amino acids. ZmCAD4 protein contained typical CAD1 domain, Zinc binding site and NADP binding site, with no transmembrane domain and signal peptide. ZmCAD4 was a non-secreted protein, and it was predicted located in the cytoplasm. The tertiary structure of ZmCAD4 was similar to AtCAD5 protein, with a 73.80% similarity. The results of phylogenetic analysis showed that ZmCAD4 was closely related to Miscanthus floridulus and Sorghum bicolor.