title: An arginine ladder in OprP mediates phosphate-specific transfer across the outer membrane.
abstract: The outer membrane protein OprP mediates the transport of essential phosphate anions into the pathogenic bacterium Pseudomonas aeruginosa. Here we report the crystallographic structure of trimeric OprP at 1.9-A resolution, revealing an unprecedented 9-residue arginine 'ladder' that spans from the extracellular surface down through a constriction zone where phosphate is coordinated. Lysine residues coat the inner periplasmic surface, creating an 'electropositive sink' that pulls the phosphates through the eyelet and into the cell.
authors.affiliation: Department of Biochemistry and Molecular Biology and the Center for Blood Research, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia V6T 1Z3, Canada.
authors.forename: Trevor F
authors.initials: TF
authors.lastname: Moraes
authors.forename: Manjeet
authors.initials: M
authors.lastname: Bains
authors.forename: Robert E W
authors.initials: RE
authors.lastname: Hancock
authors.forename: Natalie C J
authors.initials: NC
authors.lastname: Strynadka
mesh_terms: D001120:Arginine; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D018360:Crystallography, X-Ray; D017136:Ion Transport; D010710:Phosphates / Q000378:metabolism*; D018272:Porins / Q000737:chemistry* / Q000378:metabolism*; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011550:Pseudomonas aeruginosa / Q000737:chemistry* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D010710:Phosphates; D018272:Porins; C065416:oprP protein, Pseudomonas aeruginosa; D001120:Arginine