辣椒CaCOI1 基因的克隆、表达及其序列分析

 利用RT-PCR技术从辣椒中克隆到基因CaCOI1，该基因编码的蛋白质由603个氨基酸残基组成，蛋白质的分子量为68.35 kD，等电点是6.32。在蛋白质N–端有1个F-box结构域，C–端有6个富含亮氨酸结构域。二级结构分析表明，CaCOI1蛋白分子中，α–螺旋、β–折叠、β–转角和不规则卷曲分别为51.41%、13.76%、5.80%和29.03%。CaCOI1蛋白的平均亲水系数为–0.143，为亲水蛋白。蛋白质序列比对和进化树分析表明，CaCOI1与番茄LeCOI1蛋白的一致性最高（94%），进化距离最近。实时定量RT-PCR分析表明，CaCOI1在辣椒的根、茎、幼叶、成熟叶、花、青熟期果实、成熟红果等不同生长发育时期的组织中都能表达，在花中表达水平最高，是其他组织的2.8 ~ 5.4倍，表明CaCOI1在花的发育过程中起重要作用。

Molecular Cloning,Expression and Sequence Analysis of CaCOI1 from Chili Pepper

The cDNA sequence of CaCOI1 was cloned from chili pepper by RT-PCR. Bioinformatics analysis showed that CaCOI1 encodes a putative polypeptide of 603 amino acids with a calculated molecular mass of 68.35 kD and a theoretical pI of 6.32. CaCOI1 protein contains 51.41% α-helical domains,13.76% β-sheet domains,5.80% β-turn,and 29.03% random coil and is hydrophilic with a grand average of hydropathy value of –0.143. CaCOI1 protein was predicted to possess an F-box at the N-terminal and six leucine-rich repeat domains at the C-terminal. Multiple sequence alignments and phylogenetic tree analyses showed that CaCOI1 is close to the tomato LeCOI1 with an overall sequence similarity of 94%. The expression of CaCOI1 was determined by real-time quantitative RT-PCR. The result showed that the CaCOI1 gene was transcribed in different tissue organs. The expression level of CaCOI1 in flowers was about 2.8–5.4 folds higher than that in any other analyzed tissue organs. These results suggest that CaCOI1 may be involved in flower development.