title: Structure of the sucrose-specific porin ScrY from Salmonella typhimurium and its complex with sucrose.
abstract: The X-ray structure of a sucrose-specific porin (ScrY) from Salmonella typhimurium has been determined by multiple isomorphous replacement at 2.4 A resolution both in its uncomplexed form and with bound sucrose. ScrY is a noncrystallographic trimer of identical subunits, each with 413 structurally well-defined amino acids. A monomer is built up of 18 anti-parallel beta-strands surrounding a hydrophilic pore, with a topology closely similar to that of maltoporin. Two non-overlapping sucrose-binding sites were identified in difference Fourier maps. The higher permeability for sucrose of ScrY as compared to maltoporin is mainly accounted for by differences in their pore-lining residues.
authors.affiliation: Institut für Biophysik und Strahlenbiologie, Albert-Ludwigs-Universität, Freiburg im Breisgau, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Forst
authors.forename: W
authors.initials: W
authors.lastname: Welte
authors.forename: T
authors.initials: T
authors.lastname: Wacker
authors.forename: K
authors.initials: K
authors.lastname: Diederichs
mesh_terms: D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D001665:Binding Sites; D001692:Biological Transport; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008565:Membrane Proteins / Q000737:chemistry; D008969:Molecular Sequence Data; D018272:Porins / Q000737:chemistry / Q000648:ultrastructure*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011991:Receptors, Virus / Q000737:chemistry; D012486:Salmonella typhimurium / Q000737:chemistry; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012995:Solubility; D013395:Sucrose / Q000737:chemistry
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D008565:Membrane Proteins; D018272:Porins; D011991:Receptors, Virus; C079242:ScrY protein, bacteria; C016532:maltoporins; D013395:Sucrose