木质素生物合成酶CCR基因的生物信息学分析  

Bioinformatics analysis of CCR—one of the key enzymes mediated lignin biosynthesis in plants

作　　者：陈刚[1,2] 徐秉良[1,2] 白江平[1,2] 

机构地区：[1]甘肃农业大学草业学院,草业生态系统教育部重点实验室,中-美草地畜牧业可持续发展研究中心,甘肃省草业工程实验室,甘肃兰州730070 [2]甘肃省干旱生境作物学重点实验室-甘肃省作物遗传改良与种质创新重点实验室,甘肃兰州730070

出　　处：《生物信息学》2013年第1期50-57,共8页Chinese Journal of Bioinformatics

基　　金：国家自然科学基金项目(31060261;30671267);甘肃省自然科学基金项目(1107RGZA152);共同资助

摘　　要：肉桂酰辅酶A还原酶(Cinnamoyl-CoA reductase,CCR)是催化木质素特异途径的第一个关键酶,是调节碳素流向木质素潜在的控制关节点,对木质素单体的生物合成起着重要作用。通过NCBI数据库收集来自裸子植物、单子叶植物及双子叶植物的35条CCR基因的完整信息,对35条CCR基因的cDNA及其编码的氨基酸序列的进化规律、理化性质、结构域、导肽、信号肽、跨膜结构域、亲/疏水性以及蛋白质结构等性状进行了生物信息学分析与预测,构建了CCR基因的系统发育树。分析结果表明,单子叶植物CCR基因中GC的含量明显高于双子叶植物;CCR基因编码的氨基酸序列存在9个保守区域;所编码氨基酸的理化性质基本一致,但单子叶、双子叶及裸子植物的CCR基因编码主要氨基酸的种类和含量存在着差异;CCR蛋白的N-端存在一个脱氢酶/差向异构酶/辅酶Ⅰ结合蛋白的结构域,无导肽、信号肽及跨膜结构域,属亲水性蛋白;进化树绘制以及同源建模结果表明,CCR基因的进化和植物的进化基本一致,CCR蛋白三级结构模型的空间结构稳定,建模结果可靠。分析结果对于深入研究CCR蛋白在木质素合成中的作用具有一定的理论指导意义。The Cinnamoyl -CoA reductase （CCR） is the first key enzyme that catalyzed the specific pathway in lig- nin biosynthesis, it is also the speed limit enzymne that mediated the flow of the Carbon to the lignin. It thus plays an important role in the biosynthesis of lignin monomer. In order to fully understand the characteristics of this en- zyme, a total of 35 CCR genes belonging to monocotyledon, dicotyledon and gymnosperm were selected from NCBI database, the bioinformational methods were employed to analyze the amino acid composition, conserved functional domains, physical and chemical characteristics, as well as the leader peptides, signal protein, transmembrane do- main and Hydrophobicity/hydrophilicity of peptides coding by those genes. The phylogenetic tree of CCR genes was constructed and three - dimensional structure of CCR proteins were predicted and analyzed. The results showed that GC content in gymnosperm is higher than monocotyledon. Nine conserved domains were existed in all tested CCR geness and those domains shared great similarity among genes. The physical and chemical characteristics of CCR peptides are similar, but the primary structure of proteins are significantly different from each other, the data showed that one dehydrogenase/epimerase/NAD binding domain was located at the N - terminus of CCR. The three - dimensional structure of CCR revealed that this protein is stable. No obvious leader or signal peptide and transmembrane domain were detected suggested that these enzymes are hydropholicity protein and mainly functioning in the cytosol of the cell. The results also suggested that the evolution of CCR genes might corresponding to the devel- opment of the kindom of 1 plants. Therefore, the results provided great information on the CCR and be for the fur- ther research of CCR protein in lignin biosythesis.

关 键 词：木质素 CCR基因 生物信息学 进化树 同源建模 

分 类 号：Q518.2[生物学—生物化学]