title: Periplasmic disulfide isomerase DsbC is involved in the reduction of copper binding protein CueP from Salmonella enterica serovar Typhimurium.
abstract: Salmonella enterica serovar Typhimurium (S. Typhimurium) is a facultative intracellular pathogen with the ability to survive and replicate in macrophages. Periplasmic copper binding protein CueP is known to confer copper resistance to S. Typhimurium, and has been implicated in ROS scavenge activity by transferring the copper ion to a periplasmic superoxide dismutase or by directly reducing the copper ion. Structural and biochemical studies on CueP showed that its copper binding site is surrounded by conserved cysteine residues. Here, we present evidence that periplasmic disulfide isomerase DsbC plays a key role in maintaining CueP protein in the reduced state. We observed purified DsbC protein efficiently reduced the oxidized form of CueP, and that it acted on two (Cys104 and Cys172) of the three conserved cysteine residues. Furthermore, we found that a surface-exposed conserved phenylalanine residue in CueP was important for this process, which suggests that DsbC specifically recognizes the residue of CueP. An experiment using an Escherichia coli system confirmed the critical role played by DsbC in the ROS scavenge activity of CueP. Taken together, we propose a molecular insight into how CueP collaborates with the periplasmic disulfide reduction system in the pathogenesis of the bacteria.
authors.affiliation: Department of Manufacturing Pharmacy and Research Institute for Drug Development, Pusan National University, Busan, Republic of Korea.
authors.forename: Bo-Young
authors.initials: BY
authors.lastname: Yoon
authors.affiliation: Department of Manufacturing Pharmacy and Research Institute for Drug Development, Pusan National University, Busan, Republic of Korea.
authors.forename: Jin-Sik
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Agricultural Biotechnology, Center for Food and Bioconvergence, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea.
authors.forename: Si-Hyeon
authors.initials: SH
authors.lastname: Um
authors.affiliation: Department of Agricultural Biotechnology, Center for Food and Bioconvergence, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea.
authors.forename: Inseong
authors.initials: I
authors.lastname: Jo
authors.affiliation: Department of Manufacturing Pharmacy and Research Institute for Drug Development, Pusan National University, Busan, Republic of Korea.
authors.forename: Jin-Wook
authors.initials: JW
authors.lastname: Yoo
authors.affiliation: Department of Life Science, Chung-Ang University, Seoul, Republic of Korea.
authors.forename: Kangseok
authors.initials: K
authors.lastname: Lee
authors.affiliation: Department of Microbiology, Catholic University of Daegu, School of Medicine, Daegu, Republic of Korea.
authors.forename: Yong-Hak
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Department of Agricultural Biotechnology, Center for Food and Bioconvergence, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea. Electronic address: hanc210@snu.ac.kr.
authors.forename: Nam-Chul
authors.initials: NC
authors.lastname: Ha
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D003300:Copper / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D007501:Iron / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019704:Protein Disulfide-Isomerases / Q000737:chemistry / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012480:Salmonella Infections / Q000382:microbiology*; D012486:Salmonella typhimurium / Q000737:chemistry / Q000378:metabolism*; D016415:Sequence Alignment
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; C045076:Fenton's reagent; D017382:Reactive Oxygen Species; C023548:copper-binding protein; D003300:Copper; D006861:Hydrogen Peroxide; D007501:Iron; D019704:Protein Disulfide-Isomerases
keywords: Copper resistance; CueP; DsbC; Fenton reaction; Salmonella