金银花绿原酸合成酶基因LjHQT的生物信息学分析

Bioinformatics Analysis of LjHQT Gene in Lonicera japonica

羟基肉桂酰辅酶A奎尼羟基肉桂转移酶(hydroxycinnamoyl Co A quinate hydroxycinnamoyl transferase,HQT)是金银花绿原酸合成过程中的关键酶,本研究利用生物信息学的分析方法,对金银花HQT氨基酸序列与其它植物间相应片段进行同源比对和系统进化分析,并对该基因编码蛋白的理化性质,亚细胞定位、跨膜结构、二级结构和三级结构等方面进行了预测和分析。结果表明,LjHQT编码的蛋白含424个氨基酸,是一种亲水性蛋白,蛋白磷酸化位点有7个,其中丝氨酸位点6个,酪氨酸1个;目的蛋白中不存在信号肽,没有跨膜结构域,LjHQT可能定位于叶绿体或其它细胞器;其编码的氨基酸序列与中果咖啡的同源关系较近,具有较高的保守性与乌梅、葡萄的同源关系较远。二三级结构分析表明,LjHQT编码的蛋白主要由无规则卷曲和α螺旋组成,空间结构主要是螺旋和转角。本研究为LjHQT功能分析提供了重要研究基础。

The hydroxycinnamoyl CoA quinate hydroxycinnamoyl transferase （HQT） plays an important role in the synthesis of chlorogenic acid in Lonicera japonica. In this study, the HQT amino acid sequences of Lonicera japonica were compared with other plants by bioinformatic analysis and phylogenetic analysis. The physical and chemical properties, subcellular localization, transmembrane structure, two stage structure and three stage structure of the gene encoding protein were predicted and analyzed. The result showed that LjHQT gene encoded a protein with 424 amino acids, which was a hydrophilic protein, and the protein had seven phosphorylation sites, including 6 serine sites and 1 tyrosine sites. There was no signal peptide in the target protein, no transmembrane domain, and LjHQT might be located in chloroplasts or other organelles. Its encoded amino acid sequence had a close homology with Coffea canephora, but it was far from Prunus mume and Vitis vinifera. Secondary and tertiary structures analysis indicated that LjHQT protein was mainly composed of random coil and alpha helix, and spatial structure was mainly the spiral and the rotation angle. This study provided important research basis for the functional analysis of LjHQT.