ジャーナル: Nat Struct Mol Biol / 年: 2015 タイトル: A coiled-coil domain acts as a molecular ruler to regulate O-antigen chain length in lipopolysaccharide. 著者: Gregor Hagelueken / Bradley R Clarke / Hexian Huang / Anne Tuukkanen / Iulia Danciu / Dmitri I Svergun / Rohanah Hussain / Huanting Liu / Chris Whitfield / James H Naismith / 要旨: Long-chain bacterial polysaccharides have important roles in pathogenicity. In Escherichia coli O9a, a model for ABC transporter-dependent polysaccharide assembly, a large extracellular carbohydrate ...Long-chain bacterial polysaccharides have important roles in pathogenicity. In Escherichia coli O9a, a model for ABC transporter-dependent polysaccharide assembly, a large extracellular carbohydrate with a narrow size distribution is polymerized from monosaccharides by a complex of two proteins, WbdA (polymerase) and WbdD (terminating protein). Combining crystallography and small-angle X-ray scattering, we found that the C-terminal domain of WbdD contains an extended coiled-coil that physically separates WbdA from the catalytic domain of WbdD. The effects of insertions and deletions in the coiled-coil region were analyzed in vivo, revealing that polymer size is controlled by varying the length of the coiled-coil domain. Thus, the coiled-coil domain of WbdD functions as a molecular ruler that, along with WbdA:WbdD stoichiometry, controls the chain length of a model bacterial polysaccharide.
登録者
Anne Tuukkanen (EMBL-Hamburg, European Molecular Biology Laboratory (EMBL) - Hamburg outstation, Notkestraße 85, Geb. 25A, 22607 Hamburg, Deutschland, Germany)