Cartoon of the multidrug resistance transporter EmrE converting between inward-facing and outward-facing conformations. Animation of the model proposed based on the antiparallel architecture of the crystal structure, PDB 3B5D and quasi-symmetry of the cryoEM structure (Chen et al., PNAS 104:18999, 2007; Fleishman, et al., JMB 364:54, 2006).