Fig. 3.

Probing the immediate environment of E35. (A) Cartoon representation of the open form at 2.22-Å resolution for GLIC at pH 4. Only two subunits, viewed from the outside of the pentamer, are shown. The ECD and TMD interface loop regions are highlighted in green and blue. The Inset shows structurally ordered water molecules at the ECD–TMD interface crevice. Water molecules are depicted as red spheres with blue mesh representation of 2mFo-DFc electron density map contoured at a level of 1 σ and overlaid. Surrounding residues are represented as sticks and labeled. Black dashed lines represent the hydrogen-bonds network at the domain interface made of water molecules, loop F, Q193, and the M2-M3 loop. (B) Effect of MMTS binding on the function of GLIC Cys-less and mutant T158C. The same recording protocol was used for all constructs (Materials and Methods).