Figure 2—figure supplement 4: stereo diagram of domain 3 (green) with the upper part of the β-barrel and the new helix-turn-helix motif (HTH) that forms the α-barrel inside the pore as a stick model in the cryoEM map. The local resolution estimate indicates 4 to 4.5 Å for the β-barrel outside the lipid bilayer and around 5 Å for the α-barrel. Also shown is the new helix α3a (red and yellow) of the neighboring monomer, indicating a potential ionic inter-monomer interaction of Lys196 with Asp59 that would stabilize the membrane-inserted pore complex.