The Streptococcus agalactiae Ribose Binding Protein B (RbsB) Mediates Quorum Sensing Signal Uptake via Interaction with Autoinducer-2 Signals  

作　　者：FAN Bolin PAN Lixia WANG Zhongliang WANGKAHART Eakapol HUANG Yuchong YANG Dengfeng JIAN Jichang HUANG Yu WANG Bei 

机构地区：[1]College of Fishery,Guangdong Ocean University,Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animal,Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institutes,Zhanjiang 524088,China [2]National Engineering Research Center for Non-Food Biorefinery,State Key Laboratory of Non-Food Biomass and Enzyme Technology,Guangxi Academy of Sciences,Nanning 536000,China [3]Key Laboratory of Experimental Marine Biology,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China [4]Laboratory for Marine Biology and Biotechnology,Qingdao National Laboratory for Marine Science and Techno-logy,Qingdao 266237,China [5]Research Unit of Excellence for Tropical Fisheries and Technology,Division of Fisheries,Department of Agricultural Technology,Faculty of Technology,Mahasarakham University,Kantarawichai,Mahasarakham,Thailand [6]Guangxi Key Laboratory of Marine Natural Products and Combinatorial Biosynthesis Chemistry,Guangxi Beibu Gulf Marine Research Center,Guangxi Academy of Sciences,Nanning 536000,China

出　　处：《Journal of Ocean University of China》2021年第5期1285-1295,共11页中国海洋大学学报（英文版）

基　　金：This study was supported by the National Natural Sci-ence Foundation of China(Nos.31702386,31660251,31860245 and 31960203);the International Cooperation Science&Technology Planning Project of Guangdong Province of China(No.2017A050501037);the Natural Science Foundation of Guangxi Province(Nos.2018 GXNSFAA281019,2017GXNSFAA198010);the Central Government Directs Special Funds for Local Science and Technology Development Projects(No.ZY1949015);E.Wangkahart was supported financially by the Ministry of Science and Technology of Thailand and Mahasarakham University.

摘　　要：Understanding aquatic pathogen in sediments or aquacultural water is crucial to protect public health from soilborne and waterborne diseases.Quorum sensing(QS)was increasingly reported in biological wastewater treatment processes because of their inherent roles in biofilm development,bacterial aggregation and so on.The widely QS signals was Antoinducer-2(AI-2),primarily involved to allow the possibility of interspecies communication.However,the cellular components that mediate the response of Streptococcus agalactiae to AI-2 have not been fully characterized.Analysis of the complete genome sequence of S.agalactiae indi-cated that its RbsB protein has similarity to Escherichia coli LsrB and Aggregatibacter actinomycetemcomitans RbsB proteins that bind AI-2.We hypothesized that RbsB protein mediates quorum sensing signal uptake via interaction with AI-2.To evaluate the regulatory effect of RbsB on QS system,the recombinant plasmid pGEX-6p-1-RbsB was constructed and RbsB protein was purified with GST-tag.To further elucidate the role of RbsB protein binding to DPD(AI-2 precursor dihydroxypentanedione),the systemati-cally throughput circular dichroism(CD)spectroscopy,isothermal titration calorimetry200(ITC200)and molecular docking methods were employed.The high expression of soluble RbsB protein with molecular weight of 33 kDa was obtained.The thermodynamics results(ΔH<0,ΔS<0,ΔG<0)with ITC determination indicated that the binding process between DPD and RbsB was exothermic and spontaneous,with hydrogen bonds and van der Waals forces as the main binding forces.Obviously,DPD can be more easily combined with RbsB in a dose-dependent manner,suggesting that RbsB was changed in the microenvironment of DPD when the DPD concentration was between 0.8-1.0mmolL−1 and reaching the maximum binding amount.According to molecular docking,3 hydrophobic residues involved in DPD and RbsB protein stable binding were be found,and also hydrogen bonding plays a key role in the formation of the new complex.RbsB efficiently inhibited V.

关 键 词：Streptococcus agalactiae RbsB protein circular dichroism(CD)spectroscopy isothermal titration calorimetry200(ITC200) molecular docking 

分 类 号：S917.1[农业科学—水产科学]