5IUX

GLIC-V135C bimane labelled X-ray structure

Summary for 5IUX

• Entry DOI: 10.2210/pdb5iux/pdb
• Descriptor: Proton-gated ion channel, DODECYL-BETA-D-MALTOSIDE, 1,2-DIACYL-SN-GLYCERO-3-PHOSPHOCHOLINE, ... (8 entities in total)
• Functional Keywords: membrane protein, transport protein
• Biological source: Gloeobacter violaceus (strain PCC 7421)
• Total number of polymer chains: 5
• Total formula weight: 197710.55

Authors

Fourati, Z.,Menny, A.,Delarue, M. (deposition date: 2016-03-18, release date: 2017-03-29, Last modification date: 2024-11-20)

Primary citation

Menny, A.,Lefebvre, S.N.,Schmidpeter, P.A.,Drege, E.,Fourati, Z.,Delarue, M.,Edelstein, S.J.,Nimigean, C.M.,Joseph, D.,Corringer, P.J.
Identification of a pre-active conformation of a pentameric channel receptor.
Elife, 6:-, 2017

PubMed Abstract: Pentameric ligand-gated ion channels (pLGICs) mediate fast chemical signaling through global allosteric transitions. Despite the existence of several high-resolution structures of pLGICs, their dynamical properties remain elusive. Using the proton-gated channel GLIC, we engineered multiple fluorescent reporters, each incorporating a bimane and a tryptophan/tyrosine, whose close distance causes fluorescence quenching. We show that proton application causes a global compaction of the extracellular subunit interface, coupled to an outward motion of the M2-M3 loop near the channel gate. These movements are highly similar in lipid vesicles and detergent micelles. These reorganizations are essentially completed within 2 ms and occur without channel opening at low proton concentration, indicating that they report a pre-active intermediate state in the transition pathway toward activation. This provides a template to investigate the gating of eukaryotic neurotransmitter receptors, for which intermediate states also participate in activation.

PubMed: 28294942
DOI: 10.7554/eLife.23955

Experimental method

X-RAY DIFFRACTION (2.6 Å)