中文摘要：

【目的】克隆哈茨木霉几丁质合酶基因全序列，并对序列进行生物信息学分析。【方法】利用多聚酶链式反应（PCR）和染色体步移技术（genome walking）克隆几丁质合酶基因全序列；应用生物信息学软件对获得的基因序列及编码的蛋白序列进行分析；通过同源建模，对蛋白质的三维结构进行预测。【结果】从哈茨木霉（TrichodermaharzianumTh-33）中扩增得到几丁质合酶基因ThChsC（GenBank登录号HQ419000），编码区（CDS）长为2835bp，由4个外显子和3个内含子组成，开放阅读框（ORF）长2688bp，编码895个氨基酸。序列比对和同源性分析显示，该基因与串珠状赤霉（Gibberella moniliformis，ACY08039．1）和禾生刺盘孢菌（Colletotrichumgramiaicola，AAL23718．1）几丁质合酶基因相似性最高，分别为80％和81％；相应的氨基酸序列同源性均为80％，系统进化分析表明，劢珊Jf属于III型几丁质合酶亚家族。几丁质合酶ThChsC含有1个chitin—synth-1结构域，1个Chitin—synth-1N结构域，1个Chitin—synth-2结构域，3个跨膜结构域，不含信号肽，为膜结合蛋白。对预测的三维结构分析表明，ThChsC含有糖基转移酶的保守DHD结构域。【结论】从哈茨木霉Th-33中克隆得到几丁质合酶基因ThChsC,对该基因的深入研究有助于探索哈茨木霉几丁质合成的机制。

英文摘要：

[Objective] The objective of this study is to clone and make bioinformatics analysis of the sequence of chitin synthase gene ThChsC from Trichoderma harzianum. [Method] The full length of ThChsC was cloned by polymerase chain reaction （PCR） and genome walking methods, the gene sequence obtained and the putative amino acid sequence were analyzed by bioinformatics software, and the three-dimensional structure of ThChsC was predicted by homology modeling. [Result] ThChsC （GenBank accession number HQ419000） coding sequence spans 2 835 bp and is comprised of 4 extrons inserted by 3 introns. The ThChsC contains an open reading frame （ORF） of 2 688 bp capable of encoding a polypeptide of 895 amino acids and shares 80% and 81% identity to Gibberella moniliformis chsB （ACY08039.1） and Colletotrichum graminicola chs2 （AAL23718.1 ）, respectively. Phylogenetic analysis indicates that ThChsC belongs to the type III chitin synthase subfamily. The conserved Chitin_synth_1, Chitin synth 1N and Chitin_synth 2 domains and three transmembrane domains were found in the predicted ThChsC protein. A conserved DHD domain of glycosyl transferase was found in the three-dimensional structure of ThChsC predicted. [ Conclusion ] The chitin synthase gene ThChsC was cloned for the first time from Trichoderma harzianum Th-33. The further study of ThChsC will have an important significance in exploring the mechanism of chitin synthesis of Trichoderma harzianum.