ジャーナル: Cell / 年: 2020 タイトル: In Situ Structure of an Intact Lipopolysaccharide-Bound Bacterial Surface Layer. 著者: Andriko von Kügelgen / Haiping Tang / Gail G Hardy / Danguole Kureisaite-Ciziene / Yves V Brun / Phillip J Stansfeld / Carol V Robinson / Tanmay A M Bharat / 要旨: Most bacterial and all archaeal cells are encapsulated by a paracrystalline, protective, and cell-shape-determining proteinaceous surface layer (S-layer). On Gram-negative bacteria, S-layers are ...Most bacterial and all archaeal cells are encapsulated by a paracrystalline, protective, and cell-shape-determining proteinaceous surface layer (S-layer). On Gram-negative bacteria, S-layers are anchored to cells via lipopolysaccharide. Here, we report an electron cryomicroscopy structure of the Caulobacter crescentus S-layer bound to the O-antigen of lipopolysaccharide. Using native mass spectrometry and molecular dynamics simulations, we deduce the length of the O-antigen on cells and show how lipopolysaccharide binding and S-layer assembly is regulated by calcium. Finally, we present a near-atomic resolution in situ structure of the complete S-layer using cellular electron cryotomography, showing S-layer arrangement at the tip of the O-antigen. A complete atomic structure of the S-layer shows the power of cellular tomography for in situ structural biology and sheds light on a very abundant class of self-assembling molecules with important roles in prokaryotic physiology with marked potential for synthetic biology and surface-display applications.
使用したクラス数: 1 / 想定した対称性 - 点群: C1 (非対称) / アルゴリズム: FOURIER SPACE / 解像度のタイプ: BY AUTHOR / 解像度: 4.8 Å / 解像度の算出法: FSC 0.143 CUT-OFF 詳細: Tomogram generation in IMOD using the NovaCTF implementation of Turonova and Briggs. Sub-tomogram averaging performed using the AV3 package (Friedrich Foerster) applied to tubular specimens ...詳細: Tomogram generation in IMOD using the NovaCTF implementation of Turonova and Briggs. Sub-tomogram averaging performed using the AV3 package (Friedrich Foerster) applied to tubular specimens (Bharat et al, PLoS Biology, 2011) 使用したサブトモグラム数: 51866