Stepwise visualization of membrane pore formation by suilysin, a bacterial cholesterol-dependent cytolysin
Carl Leung,
Natalya V Dudkina,
Natalya Lukoyanova,
Adrian W Hodel,
Irene Farabella,
Arun P Pandurangan,
Nasrin Jahan,
Mafalda Pires Damaso,
Dino Osmanović,
Cyril F Reboul,
Michelle A Dunstone,
Peter W Andrew,
Rana Lonnen,
Maya Topf,
Helen R Saibil,
Bart W Hoogenboom
Affiliations
Carl Leung
London Centre for Nanotechnology, University College London, London, United Kingdom
Natalya V Dudkina
Department of Crystallography, Birkbeck College, London, United Kingdom; Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
Natalya Lukoyanova
Department of Crystallography, Birkbeck College, London, United Kingdom; Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
Adrian W Hodel
London Centre for Nanotechnology, University College London, London, United Kingdom
Irene Farabella
Department of Crystallography, Birkbeck College, London, United Kingdom; Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
Arun P Pandurangan
Department of Crystallography, Birkbeck College, London, United Kingdom; Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
Nasrin Jahan
Department of Infection, Immunity, and Inflammation, University of Leicester, Leicester, United Kingdom
Mafalda Pires Damaso
Department of Infection, Immunity, and Inflammation, University of Leicester, Leicester, United Kingdom
Dino Osmanović
London Centre for Nanotechnology, University College London, London, United Kingdom; Department of Physics and Astronomy, University College London, London, United Kingdom
Cyril F Reboul
Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Australia
Michelle A Dunstone
Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Australia; Department of Microbiology, Monash University, Melbourne, Australia
Peter W Andrew
Department of Infection, Immunity, and Inflammation, University of Leicester, Leicester, United Kingdom
Rana Lonnen
Department of Infection, Immunity, and Inflammation, University of Leicester, Leicester, United Kingdom
Maya Topf
Department of Crystallography, Birkbeck College, London, United Kingdom; Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
Helen R Saibil
Department of Crystallography, Birkbeck College, London, United Kingdom; Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
Bart W Hoogenboom
London Centre for Nanotechnology, University College London, London, United Kingdom; Department of Physics and Astronomy, University College London, London, United Kingdom
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.
