title: Thiol-disulphide oxidoreductase modules in the low-GC Gram-positive bacteria.
abstract: Disulphide bond formation catalysed by thiol-disulphide oxidoreductases (TDORs) is a universally conserved mechanism for stabilizing extracytoplasmic proteins. In Escherichia coli, disulphide bond formation requires a concerted action of distinct TDORs in thiol oxidation and subsequent quinone reduction. TDOR function in other bacteria has remained largely unexplored. Here we focus on TDORs of low-GC Gram-positive bacteria, in particular DsbA of Staphylococcus aureus and BdbA-D of Bacillus subtilis. Phylogenetic analyses reveal that the homologues DsbA and BdbD cluster in distinct groups typical for Staphylococcus and Bacillus species respectively. To compare the function of these TDORs, DsbA was produced in various bdb mutants of B. subtilis. Next, we assessed the ability of DsbA to sustain different TDOR-dependent processes, including heterologous secretion of E. coli PhoA, competence development and bacteriocin (sublancin 168) production. The results show that DsbA can function in all three processes. While BdbD needs a quinone oxidoreductase for activity, DsbA activity appears to depend on redox-active medium components. Unexpectedly, both quinone oxidoreductases of B. subtilis are sufficient to sustain production of sublancin. Moreover, DsbA can functionally replace these quinone oxidoreductases in sublancin production. Taken together, our unprecedented findings imply that TDOR systems of low-GC Gram-positive bacteria have a modular composition.
authors.affiliation: Department of Medical Microbiology, University Medical Center Groningen and University of Groningen, Hanzeplein 1, PO Box 30001, 9700 RB Groningen, The Netherlands.
authors.forename: Thijs R H M
authors.initials: TR
authors.lastname: Kouwen
authors.forename: Annemieke
authors.initials: A
authors.lastname: van der Goot
authors.forename: Ronald
authors.initials: R
authors.lastname: Dorenbos
authors.forename: Theresa
authors.initials: T
authors.lastname: Winter
authors.forename: Haike
authors.initials: H
authors.lastname: Antelmann
authors.forename: Marie-Claire
authors.initials: MC
authors.lastname: Plaisier
authors.forename: Wim J
authors.initials: WJ
authors.lastname: Quax
authors.forename: January Maarten
authors.initials: JM
authors.lastname: van Dijl
authors.forename: Jean-Yves F
authors.initials: JY
authors.lastname: Dubois
mesh_terms: D000469:Alkaline Phosphatase / Q000235:genetics / Q000378:metabolism; D001412:Bacillus subtilis / Q000201:enzymology* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001430:Bacteriocins / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D005816:Genetic Complementation Test; D006020:Glycopeptides; D005810:Multigene Family; D010455:Peptides / Q000378:metabolism; D010802:Phylogeny; D011490:Protein Disulfide Reductase (Glutathione) / Q000235:genetics* / Q000378:metabolism; D019704:Protein Disulfide-Isomerases / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013211:Staphylococcus aureus / Q000201:enzymology* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D001430:Bacteriocins; D029968:Escherichia coli Proteins; D006020:Glycopeptides; D010455:Peptides; C114602:sublancin 168; C450431:BdbD protein, Bacillus subtilis; D011490:Protein Disulfide Reductase (Glutathione); D000469:Alkaline Phosphatase; C114089:phoA protein, E coli; D019704:Protein Disulfide-Isomerases