Electron micrographs of liposomes incubated with Delta toxin.

<p>Scale bars correspond to 50 nm.</p

HeLa cells were incubated with 5 µg/ml Cy3-Delta toxin for 30min at 4°C (lane 1), 5 µg/ml for 30 min at 37°C (lane 2), or 10 µg/ml for 30 min at 37°C (lane 3) in DMEM medium containing 0.1% BSA.

<p>After washing, the cell lysates were elctrophoresed in a SDS-containing 10% polyacrylamide gel without reducing agent and scanned for fluorescence.</p

Data collection and structure refinement statistics.

<p>R_merge = Σ|I_i – bI_iN|/ΣI_i.</p><p>R_working = Σ|F_o – F_c|/ΣF_o.</p><p>R_free is the R-factor calculated for the cross-validated test set of reflections.</p>a<p>R_free is 4.9% of reflections.</p>b<p>As defined by MOLPROBITY.</p

Root-mean-square deviation in Angstroms, between the 198 Cα-atoms that have equivalents in all structures, excluding the stem domain, following Maximum-Likelihood-based multiple sequence alignment with Theseus-3D [39], [40].

<p>Root-mean-square deviation in Angstroms, between the 198 Cα-atoms that have equivalents in all structures, excluding the stem domain, following Maximum-Likelihood-based multiple sequence alignment with Theseus-3D <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0066673#pone.0066673-Theobald1" target="_blank">[39]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0066673#pone.0066673-Theobald2" target="_blank">[40]</a>.</p

Superposition of <i>C.</i><i>perfringens</i> Delta toxin structure with γHL-Hlg2 in grey (PDB ID: 3B07) (A), with γHL-LukF in pale green (PDB ID: 3B07) (B) and with a monomer of the αHL of <i>S. aureus</i> in yellow (PDB ID: 7AHL) (C).

<p>Colors for the different domains of <i>C. perfringens</i> Delta toxin have been kept as for Fig. 1. The conserved Arginine and Tryptophan associated with phospholipid binding are shown as sticks. Loops in the rim domain that differ in the various toxins are identified in (B) by their residue numbers in Delta.</p

Model of the Delta toxin heptameric pore shown in cartoon representation with a semi-transparent surface.

<p>Chain A is coloured cyan for the latch domain, pale green for the β-sandwich, red for the stem and raspberry for the stem domains. Remaining chains shown in single colour (pale teal, grey, lilac, pink white and yellow). (A) Top (looking down at extra-cellular face) and (B) side-view, indicating possible membrane location.</p