(a) The same ribbon diagram of a monomer taken from the trimer, as in 3B, viewed from the side, with N- and C- termini labeled. Approximate locations of planar membrane interfaces are shown as grey lines. (b) Ribbon diagrams of a trimer in an unsharpened map, contoured at 6σ, showing micelle density. Top, side and bottom views are shown. (c) Surface representation of a trimer, colored based on electrostatic potentials in aqueous solution containing 150 mM NaCl, calculated using APBS, with positive shown blue, neutral white, and negative red. Top, side and bottom views are shown.