小黑麦碳酸酐酶蛋白质三维结构预测

根据已经克隆到的小黑麦碳酸酐酶基因序列,将其概念地翻译成蛋白质的氨基酸序列。利用MEGA4.1、DNAStar5.02、SOPMA、Swiss-Model Workspace和NCBI-VAST等在线软件和服务器对该小黑麦碳酸酐酶(CA)的一级结构、二级结构及三维结构进行了分子结构模型预测,并对其三维结构进行了比对。结果显示,小黑麦碳酸酐酶定位于线粒体内膜和叶绿体类囊体膜上,具有β类碳酸酐酶所特有的保守性基序C-SA]-D-S-R-LIVM]-x-AP];SOPMA预测的二级结构显示,该酶含有α-螺旋(38.61%)、随机卷曲(54.44%)和β-折叠(6.95%)。通过VAST矢量比对工具将小黑麦碳酸酐酶与模板(lekjA)三维结构进行比对,结果显示小黑麦碳酸酐酶与豌豆β碳酸酐酶同型八聚体中的一个单体(lekjA)具有很好的匹配,故推测小黑麦碳酸酐酶全酶也可能是同型八聚体。

Structure Prediction of Carbonic Anhydrase from Triticale ( × Triticosecale Wittmack )

The nucleotide sequence of carbonic anhydrase(CA) of triticale(×Triticosecale Wittmack) was conceptually translated into an amino acid sequence based on cloned carbonic anhydrase cDNA sequence.The primary structure,secondary structure,3-D structure alignment of CA were predicted by using MEGA4.1 and DNAStar 5.02 software,SOPMA server,Swiss-Model server and NCBI-VAST server,respectively.The CA of triticale was located in mitochondrial inner membrane and chloroplast thylakoid stroma,and it had the conservative motif(C——D-S-R——x-) peculiar to β type carbonic anhydrases.In the secondary structure,α-helix,random coil and β-sheet were 38.61%,54.44% and 6.95%,respectively.The three-dimensional structure was constructed by homology modeling.The 3-D alignment of β-CA from triticale was constructed by homology modeling and a monomer of β-CA octamer from pea(lekjA) showed that the 3-D structure of β-CA from triticale could match well with the monomer.The alignment results implied that β-CA from triticale was a monomer of the β-CA octamer.