Structure of the sucrose-specific porin ScrY from Salmonella typhimurium and its complex with sucrose.
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.
Forst
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Institut für Biophysik und Strahlenbiologie, Albert-Ludwigs-Universität, Freiburg im Breisgau, Germany.
Welte
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Wacker
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Diederichs
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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
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D008565:Membrane Proteins; D018272:Porins; D011991:Receptors, Virus; C079242:ScrY protein, bacteria; C016532:maltoporins; D013395:Sucrose