Figure 4
From: ClC chloride channels
Projection structure of a bacterial ClC-type chloride channel, determined from cryoelectron microscopy of two-dimensional crystals [16]. High density (protein) appears yellow or white, whereas low density (water) appears dark red or black. The two pairs of high-density regions in each dimer probably represent part or all of the two aqueous pores in each protein complex. Reprinted with permission from [16].