High-resolution mapping of metal ions reveals principles of surface layer assembly in Caulobacter crescentus cells

DOI: 10.1016/j.str.2021.10.012

Authors: Matthew Herdman (University of Oxford) , Andriko Von Kugelgen (University of Oxford) , Danguole Kureisaite-Ciziene (MRC Laboratory of Molecular Biology) , Ramona Duman (Diamond Light Source) , Kamel El Omari (Diamond Light Source) , Elspeth F. Garman (University of Oxford) , Andreas Kjaer (University of Oxford) , Dimitrios Kolokouris (University of Oxford) , Jan Lowe (MRC Laboratory of Molecular Biology) , Armin Wagner (Diamond Light Source) , Phillip J. Stansfeld (University of Warwick) , Tanmay A. M. Bharat (University of Oxford)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Structure , VOL 55

State: Published (Approved)
Published: November 2021

Abstract: Surface layers (S-layers) are proteinaceous crystalline coats that constitute the outermost component of most prokaryotic cell envelopes. In this study, we have investigated the role of metal ions in the formation of the Caulobacter crescentus S-layer using high-resolution structural and cell biology techniques, as well as molecular simulations. Utilizing optical microscopy of fluorescently tagged S-layers, we show that calcium ions facilitate S-layer lattice formation and cell-surface binding. We report all-atom molecular dynamics simulations of the S-layer lattice, revealing the importance of bound metal ions. Finally, using electron cryomicroscopy and long-wavelength X-ray diffraction experiments, we mapped the positions of metal ions in the S-layer at near-atomic resolution, supporting our insights from the cellular and simulations data. Our findings contribute to the understanding of how C. crescentus cells form a regularly arranged S-layer on their surface, with implications on fundamental S-layer biology and the synthetic biology of self-assembling biomaterials.

Journal Keywords: S-layer; bacteria; Caulobacter crescentus; metal-ion-binding proteins; fluorescence microscopy; cryo-EM; cryo-ET; long-wavelength X-ray diffraction

Diamond Keywords: Bacteria

Subject Areas: Biology and Bio-materials


Instruments: I23-Long wavelength MX

Added On: 21/11/2021 19:54

Documents:
PIIS0969212621003804-2.pdf

Discipline Tags:

Structural biology Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX) Long Wavelength Crystallography