象草PAL基因克隆及其蛋白质结构与功能预测  

Cloning of a PALGene of Pennisetum purpureum and Prediction of Its Protein Structure and Function

作　　者：陈卫卫[1] 唐然[1] 吴昱煜 李菲[1] 张向前[1] 解新明[1,2] 

机构地区：[1]华南农业大学林学与风景园林学院,广东广州510642 [2]广东省草业工程技术研究中心,广东广州510642

出　　处：《草地学报》2016年第1期137-145,共9页Acta Agrestia Sinica

基　　金：国家自然科学基金(31272491;30972138);教育部高等学校博士学科点专项科研基金(20124404110011)资助

摘　　要：苯丙氨酸解氨酶(PAL)是植物木质素生物合成途径中的关键酶,参与木质素、类黄酮和花青素等次生代谢产物的形成。本研究以‘N51’象草(Pennisetum purpureum)为材料,通过同源克隆、3′RACE和hi-Tail PCR的方法,对PAL基因进行克隆,得到PpPALcDNA序列2429bp以及DNA序列全长3907bp。PpPAL编码的蛋白包含720个氨基酸,具有典型的GTITASGDLVPLSYIAG苯丙氨酸解氨酶保守活性基序。运用生物信息学进行分析,PpPAL基因cDNA序列与玉米(Zea mays L.)ZmPAL的相似性最高为94%,与其他禾本科植物也有着较高的相似性。在氨基酸序列系统进化分析中,PpPAL与ZmPAL遗传距离最近,并与其他禾本科植物PAL聚为一类。PpPAL蛋白的三维结构模型显示,PpPAL蛋白具有典型的"海马状"结构,表明PpPAL是典型的苯丙氨酸解氨酶家族,对木质素的合成起着重要的作用。Phenylalanine ammonia-lyase（PAL）is a key enzyme involved in lignin biosynthesis.It catalyzes the first step of phenylpropanoid pathway,which supplies precursors for a variety of secondary metabolites including phenolics,flavonoids and anthocyanin.In this study we isolated a PALgene fromPennisetum purpureumcv.N51 using homology cloning and RACE（Rapid Amplification of cDNA Ends）methods as well as hi-Tail PCR.The length of PpPALcDNA sequence was 2429 bp.The nucleotide sequence of PpPALgene was 3907 bp long and high similarity to ZmPAL,with 94%identity.The PpPALgene encoded a 720-amino-acid protein,which contained a conserved motif of GTITASGDLVPLSYIAG.In phylogenetic tree,the PpPALhad a close genetic distance with ZmPAL,and was clustered in the same group with other gramineous plants involved in lignin biosynthesis.By predicting,the three-dimensional structure of the PpPALprotein showed a typical ＂sea horse＂ shape,which indicated that PpPALis a typical family member of phenylalanine ammonia-lyase,should play an important role in lignin synthesis.

关 键 词：象草 木质素 苯丙氨酸解氨酶 生物信息学 

分 类 号：S543.9[农业科学—作物学] Q943.2[生物学—植物学]