title: Structure determination of a sugar-binding protein from the phytopathogenic bacterium Xanthomonas citri.
abstract: The uptake of maltose and related sugars in Gram-negative bacteria is mediated by an ABC transporter encompassing a periplasmic component (the maltose-binding protein or MalE), a pore-forming membrane protein (MalF and MalG) and a membrane-associated ATPase (MalK). In the present study, the structure determination of the apo form of the putative maltose/trehalose-binding protein (Xac-MalE) from the citrus pathogen Xanthomonas citri in space group P6522 is described. The crystals contained two protein molecules in the asymmetric unit and diffracted to 2.8 Å resolution. Xac-MalE conserves the structural and functional features of sugar-binding proteins and a ligand-binding pocket with similar characteristics to eight different orthologues, including the residues for maltose and trehalose interaction. This is the first structure of a sugar-binding protein from a phytopathogenic bacterium, which is highly conserved in all species from the Xanthomonas genus.
authors.affiliation: Department of Chemical and Physical Biology, Centro de Investigaciones Biologicas (CSIC), Madrid, Spain.
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Medrano
authors.affiliation: Departamento de Microbiologia, Instituto de Ciências Biomédicas II, Universidade de São Paulo, Cidade Universitária, SP, Brazil.
authors.forename: Cristiane Santos
authors.initials: CS
authors.lastname: de Souza
authors.affiliation: Department of Chemical and Physical Biology, Centro de Investigaciones Biologicas (CSIC), Madrid, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Romero
authors.affiliation: Departamento de Microbiologia, Instituto de Ciências Biomédicas II, Universidade de São Paulo, Cidade Universitária, SP, Brazil.
authors.forename: Andrea
authors.initials: A
authors.lastname: Balan
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D058619:Maltose-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D014961:X-Ray Diffraction; D014974:Xanthomonas / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D058619:Maltose-Binding Proteins
keywords: ABC transporters; Xanthomonas citri; malE