title: Crystal Structure of DsbA from Corynebacterium diphtheriae and Its Functional Implications for CueP in Gram-Positive Bacteria.
abstract: In Gram-negative bacteria in the periplasmic space, the dimeric thioredoxin-fold protein DsbC isomerizes and reduces incorrect disulfide bonds of unfolded proteins, while the monomeric thioredoxin-fold protein DsbA introduces disulfide bonds in folding proteins. In the Gram-negative bacteria Salmonella enterica serovar Typhimurium, the reduced form of CueP scavenges the production of hydroxyl radicals in the copper-mediated Fenton reaction, and DsbC is responsible for keeping CueP in the reduced, active form. Some DsbA proteins fulfill the functions of DsbCs, which are not present in Gram-positive bacteria. In this study, we identified a DsbA homologous protein (CdDsbA) in the Corynebacterium diphtheriae genome and determined its crystal structure in the reduced condition at 1.5 Å resolution. CdDsbA consists of a monomeric thioredoxin-like fold with an inserted helical domain and unique N-terminal extended region. We confirmed that CdDsbA has disulfide bond isomerase/reductase activity, and we present evidence that the N-terminal extended region is not required for this activity and folding of the core DsbA-like domain. Furthermore, we found that CdDsbA could reduce CueP from C. diphtheriae.
authors.affiliation: Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Center for Food and Bioconvergence, Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 151-921, Korea.
authors.forename: Si-Hyeon
authors.initials: SH
authors.lastname: Um
authors.affiliation: Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Center for Food and Bioconvergence, Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 151-921, Korea.
authors.forename: Jin-Sik
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Center for Food and Bioconvergence, Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 151-921, Korea.
authors.forename: Saemee
authors.initials: S
authors.lastname: Song
authors.affiliation: College of Pharmacy, Dongguk University-Seoul, Goyang 410-820, Korea.
authors.forename: Nam Ah
authors.initials: NA
authors.lastname: Kim
authors.affiliation: College of Pharmacy, Dongguk University-Seoul, Goyang 410-820, Korea.
authors.forename: Seong Hoon
authors.initials: SH
authors.lastname: Jeong
authors.affiliation: Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Center for Food and Bioconvergence, Research Institute for Agricultural and Life Sciences, Seoul National University, Seoul 151-921, Korea.
authors.forename: Nam-Chul
authors.initials: NC
authors.lastname: Ha
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D003353:Corynebacterium diphtheriae / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006094:Gram-Positive Bacteria / Q000378:metabolism*; D011487:Protein Conformation
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C051124:MerR protein, Bacteria
keywords: CueP; DsbA; disulfide; gram-positive bacteria