Extended Data Figure 5 : Comparison between the class 1 and 2 structures of CLC-K.

From: Structure of a CLC chloride ion channel by cryo-electron microscopy

Extended Data Figure 5

a, The dimer interfaces (dashed boxes) of the class 1 and 2 structures were compared. Views from the extracellular side were aligned based on the upper (red) subunit. In addition, the right panel shows superposition of a class 1 monomer (grey) onto a class 2 monomer (red). b, N-terminal amphipathic helix of class 2 structure. A side view of the class 2 structure is shown in a ribbon representation superimposed with density (mesh) of the N-terminal helix. The two subunits are shown in pale green and blue. The TM helix αB, which is visible in both class 1 and 2 structures is shown in dark green. A 12-amino-acid amphipathic helix preceding αB, visible only in class 2, is shown in yellow. The density map was sharpened with a B-factor of −120 Å2 and low-pass filtered at 4.1 Å. The approximate membrane boundaries are indicated by grey lines.