凡纳滨对虾内脏几丁质酶基因的克隆、序列分析与结构预测

Cloning,sequence and structure analysis for the chitinase gene in the viscera of Litopenaeus vannamei

几丁质酶是甲壳动物顺利完成生理性蜕壳的关键功能酶.已有研究表明几丁质酶是一个多基因家族.根据甲壳动物几丁质酶保守序列设计引物,应用反转录PCR方法从凡纳滨对虾(Litopenaeus vannamei)内脏中扩增得到部分几丁质酶编码基因片段,进一步结合RACE法,克隆得到该几丁质酶完整编码序列.生物信息学分析表明其含有信号肽序列、几丁质酶催化中心序列、PEST连接区和几丁质底物结合部位序列.序列比对发现其与中国对虾(ABB85237.1)、斑节对虾(AF157503.1)和日本对虾几丁质酶(BAA12287.1)具有很高的相似度.

Chitinase is the key enzyme in the molting of crustacean. It has been reported that chitinases are multigene family. A pair of primers was designed according to the conserved nucleotides of ehitinases and used to clone partial chitinase cDNA by RT-PCR methods. Then,by RACE（ rapid amplification of cDNA ends） technology a full length cDNA of chitinase was obtained. The deduced protein sequence was analyzed with bioinformatics which shows that the proteins contained signal peptide, chitinase catalytic domain, PEST linker and chitin binding domain. It is found that high sequence similarity existed among the chitinases of Fenneropenaeus chinensis （ ABB85237. 1 ） , Penaeus rnonodon（ AF157503.1 ）and Marsupenaeusjaponicus（ BAA12287.1 ）.