Chalcone Isomerase (CHI) catalyzes the biosynthesis of flavonoids and secondary metabolism in plants. Currently, there is no systematic analysis of CHIs gene family in Fagaceae which is available. In this study, twenty-two CHI proteins were identified in five species of the Fagaceae family. The CHI superfamily in Fagaceae can be classified into three subfamilies and five groups using phylogenetic analysis, analysis of physicochemical properties, and structural prediction. Results indicated that serine (Ser) and isoleucine (Ile) residues determine the substrate preferred by active Type I Fagaceae CHI, and the chalcone isomerase-like (CHIL) of Fagaceae had active site residues. Adaptive analysis of CHIs showed that CHIs are subject to selection pressure. The active CHI gene of Fagaceae was located in the cytoplasm, and it had the typical gene structure of CHI and contains four exons. All the twenty-two identified CHIs had the conserved domain motif 3, and the different groups had their own structural characteristics. In the process of fatty acid binding protein (FAP) evolution to CHIL and CHI, the physical and chemical properties of proteins also had significant differences in addition to changes in protein functions.

查尔酮异构酶（CHI）催化植物中类黄酮的生物合成和次级代谢。目前，尚无对菊苣科中CHIs基因家族的系统分析。在这项研究中，在五科家族的五个物种中鉴定出22种CHI蛋白。利用系统发育分析，理化性质分析和结构预测，蒲aga科的CHI超家族可分为三个亚家族和五个组。结果表明，丝氨酸（Ser）和异亮氨酸（Ile）残基决定了活性I型菊苣属CHI首选的底物，而菊苣科的查尔酮异构酶样（CHIL）具有活性位点残基。自适应分析CHIS表明CHIS承受选择压力。菊科的活跃CHI基因位于细胞质中，具有CHI的典型基因结构，包含四个外显子。所确定的所有22个CHI均具有保守的域基序3，不同的基团具有各自的结构特征。在脂肪酸结合蛋白（FAP）演变为CHIL和CHI的过程中，蛋白质的物理和化学性质除了蛋白质功能的变化外，还具有显着差异。