大菱鲆源荧光假单胞菌群体感应淬灭酶基因的克隆及生物信息学分析

Cloning and Bioinformatics Analysis of Quorum Sensing Quenching Enzyme Gene from Pseudomonas fluorescens Isolated from Turbot

导致水产品腐败变质的微生物之间存在一种信息交流机制,称之为群体感应。革兰氏阴性细菌群体感应系统主要由N-酰基高丝氨酸内酯作为信号分子,在水产品中间接调控一些腐败菌的致腐特性。可通过淬灭群体感应来抑制水产品的腐败。作为群体感应抑制剂的群体感应淬灭酶在许多细菌中被鉴定出来。为探究荧光假单胞菌PF08的pf-1240基因表达产物的潜在功能,通过基因克隆和生物信息学分析对其进行研究。结果表明:荧光假单胞菌PF08的pf-1240基因能编码一种群体感应淬灭酶,与铜绿假单胞菌PAO1的第2个高丝氨酸内酯酰化酶QuiP蛋白的相似性为65.82%。序列分析显示:pf-1240基因共编码795个氨基酸,蛋白分子式为C_(3867)H_(6010)N_(1084)O_(1160)S_(19),相对分子质量86855.96,理论等电点为7.81,不稳定系数为35.29,属于亲水蛋白。由保守结构域分析可知,该蛋白包含一个完整的青霉素酰化酶家族结构域且该家族中有许多酶被证实具有群体感应淬灭酶功能,能够分解长链群体感应信号分子AHLs。推测该蛋白也具有类似的群体感应淬灭酶功能。本研究借助生物信息学技术对其理化性质、结构等情况进行预测分析,以便深入了解荧光假单胞菌群体感应淬灭酶的性质和功能。

There is an information exchange mechanism among microorganisms that lead to the deterioration of aquatic products,called"quorum sensing"(QS).The quorum sensing system of Gram-negative bacteria mainly uses N-acyl homoserine lactone as a signal molecule to indirectly regulate the spoilage characteristics of some spoilage bacteria in aquatic products.Therefore,the spoilage of aquatic products can be inhibited by quenching quorum sensing.As a quorum sensing inhibitor,quorum sensing quenching enzyme has been identified in many bacteria.In order to explore the potential function of pf-1240 gene expression product of Pseudomonas fluorescens(PF08),gene cloning and bioinformatics analysis were used to study it.The results showed that the pf-1240 gene of Pseudomonas fluorescens PF08 might express a quorum sensing quenching enzyme,which was 65.82%similar to the second homoserine lactone acylase QuiP protein of Pseudomonas aeruginosa.Sequence analysis showed that pf-1240 gene encoded 795 amino acids.The protein molecular formula was C_(3867)H_(6010)N_(1084)O_(1160)S_(19),the relative molecular weight was 86855.96,the theoretical isoelectric point(pI)was 7.81,and the instability coefficient was 35.29.According to the conserved domain analysis,the protein contains a complete domain of penicillin acylase family,and many enzymes in this family have been proved to have quorum sensing quenching enzyme function,which can decompose quorum sensing signal molecule N-acyl homoserine lactone(AHL).It is speculated that the protein also has similar function.In this study,the physical and chemical properties and structure of the protein were predicted by bioinformatics technology,so as to understand the properties and functions of quorum sensing quenching enzyme of Pseudomonas fluorescens.