title: Functional role of oppA encoding an oligopeptide-binding protein from Lactobacillus salivarius Ren in bile tolerance.
abstract: Lactobacillus salivarius is a member of the indigenous microbiota of the human gastrointestinal tract (GIT), and some L. salivarius strains are considered as probiotics. Bile tolerance is a crucial property for probiotic bacteria to survive the transit through the GIT and exert their beneficial effects. In this work, the functional role of oppA encoding an oligopeptide transporter substrate-binding protein from L. salivarius Ren in bile salt tolerance was investigated. In silico analysis revealed that the oppA gene encodes a 61.7-kDa cell surface-anchored hydrophilic protein with a canonical lipoprotein signal peptide. Homologous overexpression of OppA was shown to confer 20-fold higher tolerance to 0.5 % oxgall in L. salivarius Ren. Furthermore, the recombinant strain exhibited 1.8-fold and 3.6-fold higher survival when exposed to the sublethal concentration of sodium taurocholate and sodium taurodeoxycholate, respectively, while no significant change was observed when exposed to sodium glycocholate and sodium glycodeoxycholate (GDCA). Our results indicate that OppA confers specific resistance to taurine-conjugated bile salts in L. salivarius Ren. In addition, the OppA overexpression strain also showed significant increased resistance to heat and salt stresses, suggesting the protective role of OppA against multiple stresses in L. salivarius Ren.
authors.affiliation: Key Laboratory of Functional Dairy, Co-constructed by Ministry of Education and Beijing Municipality, College of Food Science and Nutritional Engineering, China Agricultural University, 17 Qing Hua East Road, Hai Dian District, Beijing, 100083, China.
authors.forename: Guohong
authors.initials: G
authors.lastname: Wang
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.forename: Xiayin
authors.initials: X
authors.lastname: Ma
authors.forename: Haoran
authors.initials: H
authors.lastname: An
authors.forename: Zhengyuan
authors.initials: Z
authors.lastname: Zhai
authors.forename: Fazheng
authors.initials: F
authors.lastname: Ren
authors.forename: Yanling
authors.initials: Y
authors.lastname: Hao
mesh_terms: D000595:Amino Acid Sequence; D000626:Aminopeptidases / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001646:Bile; D001647:Bile Acids and Salts / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D003547:Cysteine Synthase / Q000235:genetics / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000235:genetics / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D015964:Gene Expression Regulation, Bacterial; D058685:Genetic Pleiotropy; D007778:Lactobacillus / Q000235:genetics* / Q000378:metabolism; D008074:Lipoproteins / Q000235:genetics* / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D013312:Stress, Physiological
chemical_list: D001426:Bacterial Proteins; D001647:Bile Acids and Salts; D002352:Carrier Proteins; D004269:DNA, Bacterial; D008074:Lipoproteins; D008565:Membrane Proteins; D009842:Oligopeptides; C046506:oligopeptide-binding protein, bacteria; D003547:Cysteine Synthase; D000626:Aminopeptidases; C022450:prolyl aminopeptidase; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; C098392:PepX dipeptidyl aminopeptidase