Extended 2D class averages and three unique structural states of membrane-bound VCC . (A) A panel showing only side views of the 2D projections where the PFT molecules are seen tethered between bilayers of asolectin-cholesterol liposomes. An enlarged view shows the transmembrane channel passing through the two layers of lipid density. A 3D reconstruction of VCC obtained at 5.15 Å in the presence of a large volume of lipid. (B) 3D volumes of the different structural states of VCC and 2D class averages (enlarged from panel A) of membrane-bound VCC suggest different extents of lipid interaction of the oligomer. Scale bar = 100 Å.