Structural Insights into the Oligomerization and Architecture of Eukaryotic Membrane Pore-Forming Toxins

Archive ouverte

Mechaly, Ariel, E | Bellomio, Augusto | Gil-Cartón, David | Morante, Koldo | Valle, Mikel | González-Mañas, Juan Manuel | Guérin, Diego M.A.

Edité par CCSD ; Elsevier (Cell Press) -

International audience. Pore-forming toxins (PFTs) are proteins that are secreted as soluble molecules and are inserted into membranes to form oligomeric transmembrane pores. In this paper, we report the crystal structure of Fragaceatoxin C (FraC), a PFT isolated from the sea anemone Actinia fragacea, at 1.8 Å resolution. It consists of a crown-shaped nonamer with an external diameter of about 11.0 nm and an internal diameter of approximately 5.0 nm. Cryoelectron microscopy studies of FraC in lipid bilayers reveal the pore structure that traverses the membrane. The shape and dimensions of the crystallographic oligomer are fully consistent with the membrane pore. The FraC structure provides insight into the interactions governing the assembly process and suggests the structural changes that allow for membrane insertion. We propose a nonameric pore model that spans the membrane by forming a lipid-free α-helical bundle pore.

Consulter en ligne

Suggestions

Du même auteur

Pores of the toxin FraC assemble into 2D hexagonal clusters in both crystal structures and model membranes

Archive ouverte | Mechaly, Ariel, E | CCSD

International audience. The recent high-resolution structure of the toxin FraC derived from the sea anemone Actinia fragacea has provided new insight into the mechanism of pore formation by actinoporins. In this wor...

Segmental Helical Motions and Dynamical Asymmetry Modulate Histidine Kinase Autophosphorylation

Archive ouverte | Mechaly, Ariel, E | CCSD

International audience. Histidine kinases (HKs) are dimeric receptors that participate in most adaptive responses to environmental changes in prokaryotes. Although it is well established that stimulus perception tri...

Structural insights into the signalling mechanisms of two-component systems

Archive ouverte | Jacob-Dubuisson, Françoise | CCSD

International audience. Two-component systems reprogramme diverse aspects of microbial physiology in response to environmental cues. Canonical systems are composed of a transmembrane sensor histidine kinase and its ...

Chargement des enrichissements...