Stepwise visualization of membrane pore formation by suilysin, a bacterial cholesterol-dependent cytolysin.pdf (2.65 MB)
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Stepwise visualization of membrane pore formation by suilysin, a bacterial cholesterol-dependent cytolysin

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journal contribution
posted on 11.03.2015, 09:52 by C. Leung, N. V. Dudkina, N. Lukoyanova, A. W. Hodel, I. Farabella, A. P. Pandurangan, Nasrin Jahan, Mafalda Pires Damaso, D. Osmanovic, C. F. Reboul, M. A. Dunstone, Peter W. Andrew, Rana Lonnen, M. Topf, H. R. Saibil, B. W. Hoogenboom
Membrane attack complex/perforin/cholesterol-dependent cytolysin (MACPF/CDC) proteins constitute a major superfamily of pore-forming proteins that act as bacterial virulence factors and effectors in immune defence. Upon binding to the membrane, they convert from the soluble monomeric form to oligomeric, membrane-inserted pores. Using real-time atomic force microscopy (AFM), electron microscopy (EM), and atomic structure fitting, we have mapped the structure and assembly pathways of a bacterial CDC in unprecedented detail and accuracy, focussing on suilysin from Streptococcus suis. We show that suilysin assembly is a noncooperative process that is terminated before the protein inserts into the membrane. The resulting ring-shaped pores and kinetically trapped arc-shaped assemblies are all seen to perforate the membrane, as also visible by the ejection of its lipids. Membrane insertion requires a concerted conformational change of the monomeric subunits, with a marked expansion in pore diameter due to large changes in subunit structure and packing.

Funding

BBSRC (BB/G011729/1, BB/J005932/1, BB/J006254 and BB/ K01692X/1), the ERC (advanced grant 294408), and the Leverhulme Trust (RPG-2012-519).

History

Citation

eLife , 2014;3:e04247

Author affiliation

/Organisation/COLLEGE OF MEDICINE, BIOLOGICAL SCIENCES AND PSYCHOLOGY/School of Medicine/Department of Infection, Immunity and Inflammation

Version

VoR (Version of Record)

Published in

eLife

Publisher

Sciences Publications

issn

2050-084X

eissn

2050-084X

Available date

11/03/2015

Publisher version

http://elifesciences.org/content/3/e04247/abstract-1

Notes

Figure supplement 1. Symmetry of suilysin prepores and pores, determined by negative-stain EM. DOI: 10.7554/eLife.04247.004 Figure supplement 2. Resolution curves for EM maps. DOI: 10.7554/eLife.04247.005 Figure supplement 3. Electrostatic potential maps and interacting residues. DOI: 10.7554/eLife.04247.006 Figure supplement 4. Comparison between prepore and crystal structure conformations. DOI: 10.7554/eLife.04247.007 Accession codes for EM maps: prepore EMD-12698, pore EMD-12711.

Language

en