3W9P

Crystal structure of monomeric FraC (second crystal form)

Summary for 3W9P

• Entry DOI: 10.2210/pdb3w9p/pdb
• Related: 3LIM 3VWI
• Descriptor: Fragaceatoxin C (2 entities in total)
• Functional Keywords: beta-sandwich, amphipathic alpha-helix, actinoporin, pore-forming toxin, cytolysin, membrane lipids, secreted protein, toxin
• Biological source: Actinia fragacea (Strawberry anemone)
• Cellular location: Secreted : B9W5G6
• Total number of polymer chains: 2
• Total formula weight: 39755.00

Authors

Caaveiro, J.M.M.,Tanaka, K.,Tsumoto, K. (deposition date: 2013-04-09, release date: 2014-04-09, Last modification date: 2023-11-08)

Primary citation

Tanaka, K.,Caaveiro, J.M.M.,Morante, K.,Gonzalez-Manas, J.M.,Tsumoto, K.
Structural basis for self-assembly of a cytolytic pore lined by protein and lipid
Nat Commun, 6:6337-6337, 2015

PubMed Abstract: Pore-forming toxins (PFT) are water-soluble proteins that possess the remarkable ability to self-assemble on the membrane of target cells, where they form pores causing cell damage. Here, we elucidate the mechanism of action of the haemolytic protein fragaceatoxin C (FraC), a α-barrel PFT, by determining the crystal structures of FraC at four different stages of the lytic mechanism, namely the water-soluble state, the monomeric lipid-bound form, an assembly intermediate and the fully assembled transmembrane pore. The structure of the transmembrane pore exhibits a unique architecture composed of both protein and lipids, with some of the lipids lining the pore wall, acting as assembly cofactors. The pore also exhibits lateral fenestrations that expose the hydrophobic core of the membrane to the aqueous environment. The incorporation of lipids from the target membrane within the structure of the pore provides a membrane-specific trigger for the activation of a haemolytic toxin.

PubMed: 25716479
DOI: 10.1038/ncomms7337

Experimental method

X-RAY DIFFRACTION (2.1 Å)