西瓜半胱氨酸蛋白酶基因ClCP1克隆及其生物信息学分析

目的]克隆西瓜半胱氨酸蛋白酶基因CICP2，并对其进行生物信息学分析。方法]以西瓜花蕾cDNA为模板，借助西瓜全基因组数据库，采用RT—PCR方法对西瓜半胱氨酸蛋白酶基因进行克隆并进行生物信息学分析。结果]克隆得到一个开放阅读框长度为960bp的序列，命名为C1CP1。该基因编码3t9个氨基酸。C1CP1基因的保守结构域分析结果表明，CICP1属于木瓜蛋白酶家族基因，与已知其他植物半胱氨酸蛋白酶在氨基酸序列上有56％～85％的相似性。聚类分析结果显示，C1CP1与同为葫芦科的黄瓜cP基因亲缘关系较近。结论]CICP1属于西瓜木瓜蛋白酶家族新基因，为进一步研究西瓜半胱氨酸蛋白酶基因C1CP1的表达和功能奠定了基础。

Cloning and Bioinformatic Analysis of Cysteine Proteinase 1 in Citruflus lanatus Matsum

Objective ] This study aimed to clone the cysteine proteinase （CP） from watermelon （ Citrullus lanatus Matsum） for bioinformatic analysis. Method] Based on the watermelon database, coding sequence of a eysteine proteinase was cloned from floral buds of watermelon u- sing RT- PCR for bioinformatic analysis. Result ] A cysteine proteinase was cloned and named CICP1. Sequence analysis indicated that ClCP1 contains an opening reading frame （ORF） of 960 bp encoding 319 predicted amino acids with a molecular mass of 77.28 kD and a pI of 5.13. C1CP1 belongs to the papain-like subfamily C1A using conserved domain analysis. Sequence alignment and phylogenetic analysis re- vealed that CICP1 shared 85% homology with Cucumis sativus CP and shared 56% -66% homology with other plants. Conclusion] C1CP1 encodes a novel papain-like eysteine proteinase. The analysis of ClCP1 in watermelon provides a theoretical basis to further explore the biologi- cal function during growth and development in watermelon.