title: The 285 kDa Bap/RTX hybrid cell surface protein (SO4317) of Shewanella oneidensis MR-1 is a key mediator of biofilm formation.
abstract: Shewanella oneidensis, a Gram-negative bacterium with unusual respiratory versatility, is found in soil and sediment environments, and sporadically as an opportunistic pathogen in humans and aquatic animals. The ability to form biofilms is a critical factor in the environmental spread and survival of this bacterium. We subjected S. oneidensis MR-1 to random transposon insertion mutagenesis to identify genes contributing to the ability of the organism to form biofilms on polystyrene surfaces. Follow-up of the clone that was most heavily impaired in biofilm formation led to the identification of a novel 285 kDa multi-domain protein which we have termed biofilm-promoting factor A (BpfA). BpfA is secreted by a type I secretion system to the cell surface, where it is a requisite for biofilm development. The BpfA-dependent biofilm phenotype is positively modulated by sub to low millimolar amounts of calcium. Intriguingly, BpfA features structural motifs and sequence fingerprints that can be traced back to bacterial Bap-family and RTX family proteins, two protein families harboring putative and established calcium binding sites.
authors.affiliation: Laboratory for Protein Biochemistry and Biomolecular Engineering, Ghent University, 9000 Ghent, Belgium. sofie.theunissen@piontechnologies.be
authors.forename: Sofie
authors.initials: S
authors.lastname: Theunissen
authors.forename: Lina
authors.initials: L
authors.lastname: De Smet
authors.forename: Ann
authors.initials: A
authors.lastname: Dansercoer
authors.forename: Bart
authors.initials: B
authors.lastname: Motte
authors.forename: Tom
authors.initials: T
authors.lastname: Coenye
authors.forename: Jozef J
authors.initials: JJ
authors.lastname: Van Beeumen
authors.forename: Bart
authors.initials: B
authors.lastname: Devreese
authors.forename: Savvas N
authors.initials: SN
authors.lastname: Savvides
authors.forename: Bjorn
authors.initials: B
authors.lastname: Vergauwen
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018441:Biofilms / Q000254:growth & development*; D002118:Calcium / Q000378:metabolism; D004251:DNA Transposable Elements; D055786:Gene Knockout Techniques; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008970:Molecular Weight; D016254:Mutagenesis, Insertional; D017386:Sequence Homology, Amino Acid; D020592:Shewanella / Q000235:genetics / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D008565:Membrane Proteins; D002118:Calcium