杂交云杉(Picea engelmannii-glauca)不同类型几丁质酶的生物信息学分析

Bioinformatics Analysis of Different Classes of Chitinases in Picea engelmannii-glauca

根据氨基酸的序列特征,可将植物几丁质酶划分为Ⅰ~Ⅶ七类。由NCBI数据库可知,对于云杉不同类型几丁质酶研究甚少,其中以杂交云杉(Picea engelmannii-glauca)上传的氨基酸序列最为完善,包括Ⅰ、Ⅱ、Ⅳ、Ⅶ四类,但均未对其生物信息学进行分析。本研究以杂交云杉的四类几丁质酶氨基酸序列为研究对象,利用生物信息学分析方法对其蛋白质进行鉴定。结果表明,四类几丁质酶蛋白分子量大小为24~36 kD,均为亲水性蛋白;具潜在磷酸化位点,且位于丝氨酸、苏氨酸和酪氨酸上,但不含糖基化位点;除Ⅱ类几丁质酶外,其余均具信号肽位点;亚细胞定位发现,四类几丁质酶蛋白都属分泌蛋白;保守结构域分析可知,四类几丁质酶蛋白全为蛋白19家族,且兼具溶菌酶活性;二级结构主要由4部分组成,包括无规则卷曲、α-螺旋、延伸链和β-转角,除Ⅰ和Ⅳ类外,其余两类均具1个跨膜结构域;系统发育树分析可知,四类几丁质酶进化过程既有所发展,又相对保守。该研究为深入研究云杉属几丁质酶的生物学功能和调控机制提供一定的理论依据,为云杉的抗病性育种提供一定的依据。

According to the sequence characteristics of amino acids,plant chitinases can be classified into seven different classes,Ⅰto Ⅶ.Known by the NCBI database,different classes of chitinases in Picea are few studied.Among them,the amino acid sequences of Picea engelmannii-glauca are the most complete,includingⅠ,Ⅱ,Ⅳ,and Ⅶ.However,no analysis of their bioinformatics has been made.In this study,four classes of chitinase amino acid sequences of Picea engelmannii-glauca were used as research objects,and their proteins were identified by bioinformatics analysis method.The results showed that the molecular mass of four classes of chitinase proteins ranged from 24~36 kD,all of which were hydrophilic proteins.They had potential phosphorylation sites on serine,threonine and tyrosine,but did not contain glycosylation sites.Except for the classⅡchitinase,the rest had signal peptide sites.Subcellular localization found that the four classes of chitinase proteins were secreted proteins.Conserved domain analysis showed that they belonged to the GH family 19 and had lysozyme activity.The secondary structure were mainly composed of 4 parts,including random coil,α-helix,extended chain and β-turn.Except for theⅠand Ⅳ,the other had a transmembrane domain.Phylogenetic analysis showed that the evolution of the four classes of chitinase proteins were both developmental and relatively conservative.This study provides a theoretical basis for the futher study of the biological functions and regulatory mechanisms of chitinases in Picea,and lays a foundation for the breeding of disease resistance of Picea.