9G93

CryoET structure of the in vitro grown Bacillus anthracis Sap S-layer

Summary for 9G93

• Entry DOI: 10.2210/pdb9g93/pdb
• EMDB information: 45459
• Descriptor: S-layer protein sap (1 entity in total)
• Functional Keywords: s-layer, exoskeleton, surface array, structural protein
• Biological source: Bacillus anthracis str. '34F2 (NMRC)'
• Total number of polymer chains: 11
• Total formula weight: 954081.22

Authors

Sogues, A.,Leigh, K.,Van der Verren, S.,Kudryashev, M.,Pak, A.,Halingstad, E.V.,Cecil, A.J.,Fioravanti, A.,Remaut, H. (deposition date: 2024-07-24, release date: 2024-12-18)

Primary citation

Sogues, A.,Leigh, K.,Halingstad, E.V.,Van der Verren, S.E.,Cecil, A.J.,Fioravanti, A.,Pak, A.J.,Kudryashev, M.,Remaut, H.
Architecture of the Sap S-layer of Bacillus anthracis revealed by integrative structural biology.
Proc.Natl.Acad.Sci.USA, 121:e2415351121-e2415351121, 2024

PubMed Abstract: is a spore-forming gram-positive bacterium responsible for anthrax, an infectious disease with a high mortality rate and a target of concern due to bioterrorism and long-term site contamination. The entire surface of vegetative cells in exponential or stationary growth phase is covered in proteinaceous arrays called S-layers, composed of Sap or EA1 protein, respectively. The Sap S-layer represents an important virulence factor and cell envelope support structure whose paracrystalline nature is essential for its function. However, the spatial organization of Sap in its lattice state remains elusive. Here, we employed cryoelectron tomography and subtomogram averaging to obtain a map of the Sap S-layer from tubular polymers that revealed a conformational switch between the postassembly protomers and the previously available X-ray structure of the condensed monomers. To build and validate an atomic model of the lattice within this map, we used a combination of molecular dynamics simulations, X-ray crystallography, cross-linking mass spectrometry, and biophysics in an integrative structural biology approach. The Sap lattice model produced recapitulates a close-to-physiological arrangement, reveals high-resolution details of lattice contacts, and sheds light on the mechanisms underlying the stability of the Sap layer.

PubMed: 39652757
DOI: 10.1073/pnas.2415351121

Experimental method

ELECTRON MICROSCOPY (7.2 Å)