title: Crystal structure of the phosphate-binding protein (PBP-1) of an ABC-type phosphate transporter from Clostridium perfringens.
abstract: Phosphate limitation is an important environmental stress that affects the metabolism of various organisms and, in particular, can trigger the virulence of numerous bacterial pathogens. Clostridium perfringens, a human pathogen, is one of the most common causes of enteritis necroticans, gas gangrene and food poisoning. Here, we focused on the high affinity phosphate-binding protein (PBP-1) of an ABC-type transporter, responsible for cellular phosphate uptake. We report the crystal structure (1.65 Å resolution) of the protein in complex with phosphate. Interestingly, PBP-1 does not form the short, low-barrier hydrogen bond with phosphate that is typical of previously characterized phosphate-binding proteins, but rather a canonical hydrogen bond. In its unique binding configuration, PBP-1 forms an unusually high number of hydrogen bonds (14) with the phosphate anion. Discrimination experiments reveal that PBP-1 is the least selective PBP characterised so far and is able to discriminate phosphate from its close competing anion, arsenate, by ~150-fold.
authors.affiliation: URMITE UMR CNRS-IRD 6236, IFR48, Faculté de Médecine et de Pharmacie, Université de la Méditerranée, Marseille, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Gonzalez
authors.affiliation: URMITE UMR CNRS-IRD 6236, IFR48, Faculté de Médecine et de Pharmacie, Université de la Méditerranée, Marseille, France.
authors.forename: Magali
authors.initials: M
authors.lastname: Richez
authors.affiliation: 1] URMITE UMR CNRS-IRD 6236, IFR48, Faculté de Médecine et de Pharmacie, Université de la Méditerranée, Marseille, France [2] University of Minnesota, Department of Biochemistry, Molecular Biology and Biophysics &Biotechnology Institute, St. Paul, MN 55108, USA.
authors.forename: Celine
authors.initials: C
authors.lastname: Bergonzi
authors.affiliation: URMITE UMR CNRS-IRD 6236, IFR48, Faculté de Médecine et de Pharmacie, Université de la Méditerranée, Marseille, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Chabriere
authors.affiliation: University of Minnesota, Department of Biochemistry, Molecular Biology and Biophysics &Biotechnology Institute, St. Paul, MN 55108, USA.
authors.forename: Mikael
authors.initials: M
authors.lastname: Elias
mesh_terms: D001149:Arsenates / Q000737:chemistry; D003015:Clostridium Infections / Q000378:metabolism / Q000473:pathology; D003016:Clostridium perfringens / Q000737:chemistry* / Q000472:pathogenicity; D018360:Crystallography, X-Ray; D006801:Humans; D006860:Hydrogen Bonding; D028044:Phosphate-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D010710:Phosphates / Q000737:chemistry*; D011487:Protein Conformation
chemical_list: D001149:Arsenates; D028044:Phosphate-Binding Proteins; D010710:Phosphates; C025657:arsenic acid