Gating of the proton-gated ion channel from Gloeobacter violaceus at pH 4 as revealed by X-ray crystallography.

ABSTRACT: Cryoelectron microscopy and X-ray crystallography have recently been used to generate structural models that likely represent the unliganded closed-channel conformation and the fully liganded open-channel conformation of different members of the nicotinic-receptor superfamily. To characterize the structure of the closed-channel conformation in its liganded state, we identified a number of positions in the loop between transmembrane segments 2 (M2) and 3 (M3) of a proton-gated ortholog from the bacterium Gloeobacter violaceus (GLIC) where mutations to alanine reduce the liganded-gating equilibrium constant, and solved the crystal structures of two such mutants (T25'A and Y27'A) at pH ~4.0. At the level of backbone atoms, the liganded closed-channel model presented here differs from the liga

SUBMITTER: Gonzalez-Gutierrez G 

PROVIDER: S-EPMC3832033 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature