6t72

Publication Abstract from PubMed

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.

In Situ Structure of an Intact Lipopolysaccharide-Bound Bacterial Surface Layer.,von Kugelgen A, Tang H, Hardy GG, Kureisaite-Ciziene D, Brun YV, Stansfeld PJ, Robinson CV, Bharat TAM Cell. 2020 Jan 23;180(2):348-358.e15. doi: 10.1016/j.cell.2019.12.006. Epub 2019 , Dec 26. PMID:31883796^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.