推定第四类羊毛硫素合成酶生物信息学分析

Bioinformatics to predict type IV lanthipeptide synthetases

【目的】获得更多关于第四类羊毛硫素合成酶的序列及蛋白结构特征信息,并为研究其作用机制及生物学功能奠定基础。【方法】应用多种软件分析和预测了山丘链霉菌、枯草芽孢杆菌、肺炎双球菌、惰性乳杆菌、德氏乳杆菌、长双歧杆菌、拟无枝酸菌、大芬戈尔德菌中此类蛋白质的理化性质、结构域、二级结构等,同时采用邻位连接法对这8种蛋白及其结构域进行了进化树的构建。【结果】所研究的这8种蛋白均为亲水性蛋白,均无信号肽;山丘链霉菌、枯草芽孢杆菌、肺炎双球菌、德氏乳杆菌、长双歧杆菌、拟无枝酸菌、大芬戈尔德菌的此类合成酶属于酸性蛋白,惰性乳杆菌的类第四类羊毛硫素合成酶属于碱性蛋白;除山丘链霉菌、枯草芽孢杆菌、肺炎双球菌的此类合成酶不稳定外,其它菌株的合成酶均稳定;进化结果表明枯草芽孢杆菌和肺炎链球菌同源性最高,LANC-like结构域与合成酶的进化关系保持了高度的一致,而STYKc/S_TKc结构域的进化关系表现出了一定的差异;二级结构主要以α螺旋和无规卷曲为主;所有的蛋白均有LANC-like结构域。【结论】类第四类羊毛硫素合成酶在不同的菌种中具有一定的保守性,因此能够发挥相似的生物学功能。研究结果对进一步研究第四类羊毛硫素合成酶具有一定的参考价值,尤其是为通过该途径进一步提高枯草芽孢杆菌生防价值提供基础。

[Objective] This study aimed to get more information about sequence and protein structure of type IV lanthipeptide synthetases. [Methods] Eight potential type IV lanthipeptide synthetases were chosen from Bacillus subtilis, Streptomyces collinus Tu 365, Lactobacillus iners Lactin V, Streptococcus pneumoniae, Lactobacillus delbruecki, Bifidobacterium longum, Amycolatopsis azurea and Finegoldia magna, and their physicochemical properties, domains, secondary structures were analyzed and predicted using different softwares. By using the Neighbor-joining method of Molecular Evolutionary Genetics Analysis software, a dendrogram was obtained based on genetic distances. [Results] All eight proteins were hydrophilicity and there was no signal peptide in them. The proteins in S. collinus Tu 365, B. subtilis, S. pneumoniae, Lactobacillus delbruecki, Bifidobacterium longum, Amycolatopsis azurea and Finegoldia magna were acidic whereas the others were alkaline. The proteins in S. collinus Tu 365, B. subtilis and S. pneumoniae were unstable whereas the others were stable. The evolutionary analysis showed that B. subtilis had the closest genetic relationship with S. pneumonia. The evolutionary relationships of LANC-like domains were similar to total synthase, which was different from STYKc/S_TKc domains. Alpha helix and coil were the basic secondary structure. All those proteins contained LANC-like domain. [Conclusion] All that eight synthetases have their conservative structure in different bacteria, therefore, they can play the similar biological functions. All these results will provide information of the type IV lanthipeptide synthetase for further study, especially for improving the bio-control value of B. subtilis.