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.
プロトコル: SINGLE WAVELENGTH / 単色(M)・ラウエ(L): M / 散乱光タイプ: x-ray
放射波長
波長: 0.9173 Å / 相対比: 1
反射
解像度: 3.87→128.2 Å / Num. obs: 9283 / % possible obs: 98.6 % / Observed criterion σ(I): 2 / 冗長度: 4 % / Rmerge(I) obs: 0.07 / Net I/σ(I): 11.6
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解析
ソフトウェア
名称: REFMAC / バージョン: 5.8.0049 / 分類: 精密化
精密化
構造決定の手法: OTHER 開始モデル: NONE 解像度: 3.87→128.19 Å / Cor.coef. Fo:Fc: 0.909 / Cor.coef. Fo:Fc free: 0.875 / SU B: 141.891 / SU ML: 0.861 / 交差検証法: THROUGHOUT / ESU R Free: 0.916 / 立体化学のターゲット値: MAXIMUM LIKELIHOOD / 詳細: HYDROGENS HAVE BEEN ADDED IN THE RIDING POSITIONS.