烟草Ⅰ型几丁质酶的生物信息学分析

Bioinformatics Analysis of Chitinase Class Ⅰ in Tobacco

旨在对烟草Ⅰ型几丁质酶进行生物信息学分析,了解其生物学特征,为下一步研究烟草Ⅰ型几丁质酶在烟草抗病过程中的作用奠定基础。采用生物信息学的方法,对已在NCBI上登陆的烟草、拟南芥、水稻、菜豆的Ⅰ型几丁质酶（chitinase,ChiⅠ）氨基酸序列特征和进化关系进行了预测和分析。结果表明,这4种植物Ⅰ型几丁质酶的分子量大小在28~37 kDa之间,均具有信号肽,结构域高度保守,均具有几丁质结合区（Cht BD1）和催化功能区（Glyco_hydro_19）;烟草中的3种Ⅰ型几丁质酶序列相似性较高,可以聚为一类;烟草与拟南芥和菜豆中的一种ChiⅠ遗传距离较近,而与水稻中ChiⅠ的遗传距离较远。通过分析发现,烟草Ⅰ型几丁质酶有着与其他植物中该酶相同的特性,为进一步研究烟草抗病蛋白提供理论依据。

The aim of this study was to analyze the characteristics of ChiⅠ（chitinase classⅠ） in tobacco by using bioinformatics methods and tools. This research laid foundations for further research of ChiⅠ on disease of tobacco. Bioinformatic methods were used to predict and analyze the ChiⅠ（chitinase classⅠ） from NCBI of Nicotiana tabacum, Arabidopsis thaliana, Oryza sativa and Phaseolus vulgaris in sequence characteristics and phylogenetic relationships. The results demonstrated that the molecular weight of the ChiⅠ with signal peptide from the four plants were 28-37 kDa. The ChiⅠ had a glycoside hydrolase family 19 domain and N-terminal chitin binding domain, which was highly conservative among chitinases from several different plant species.The phylogenetic relationship of Nt-ChiA, Nt-ChiB and Nt-ChiC, and the relationship between ChiⅠ from Nicotiana tabacum and one of ChiⅠ from Arabidopsis thaliana and Phaseolus vulgaris was closer than that from Oryza sativa. The result implied the properties of ChiⅠ in tobacco were almost the same as that of other plants. This study provided the basis for further research on tobacco disease resistance proteins.