中文摘要：

【目的】克隆玉米大斑病菌CnB基因,并进行初步的生物信息学分析。【方法】采用cDNA末端快速扩增（Rapid Amplification of cDNA Ends,RACE）技术,扩增玉米大斑病菌CnB基因全长cDNA序列和DNA序列。运用相关生物信息学软件对该基因序列进行分析和预测其编码蛋白的结构功能。【结果】CnB基因含4个外显子和3个内含子,最大开放阅读框为525bp（GenBank登录号EF 469732）,编码174个氨基酸;预测蛋白含约59.77%的α螺旋,8.62%的β转角,6.32%的延伸串,25.29%的不规则卷曲;含有高度保守的4个“EF-hand”Ca^2＋结合区域,属于Ca^2＋结合蛋白家族成员,与小麦叶枯病菌（Phaeosphaeria nodorum）、灰葡萄孢（B.cinerea）、粗糙麦孢霉（Neurospora crassa）等病原真菌中CnB基因有90%以上的氨基酸同源性。【结论】首次在玉米大斑病菌中克隆得到CnB基因,为进一步研究该基因功能奠定基础。

英文摘要：

[Objective] To clone and identify CnB gene from Setosphaeria turcica and to perform the primary bioinformatic analysis. [Methods] Using RACE method, we isolated the completed cDNA sequence and DNA sequence of CnB gene from S. turcica. Corresponding structure and functions were predicted by the bioinformatic software. [Results] The results showed that CnB gene had 4 exons and 3 introns and the largest open reading frame was 525 bp which encoded a protein of 174 amino acid residues. The predicted secondary structure composition for the protein contained about 59.77% alpha helixes, 8.62% beta turn, 6.32% extended strand and 25.29% random coil. The CnB gene of S. turcica had 4 ＂EF-hand＂ calcium-binding regions, and showed 90% homology with CnB gene of P. nodorum, B. cinerea and Neurospora crassa. [Conclusion] The CnB gene was successfully cloned from S. turcica for the first time, providing a good foundation for further research on its function.