3PJS

Mechanism of Activation Gating in the Full-Length KcsA K+ Channel

Summary for 3PJS

• Entry DOI: 10.2210/pdb3pjs/pdb
• Descriptor: FAB light chain, FAB heavy chain, Voltage-gated potassium channel (3 entities in total)
• Functional Keywords: ion channel, conducts k+ ions, cell membrane, transport protein
• Biological source: Mus musculus; More
• Cellular location: Cell membrane; Multi-pass membrane protein: P0A334
• Total number of polymer chains: 8
• Total formula weight: 168972.88

Authors

Uysal, S.,Cuello, L.G.,Kossiakoff, A.,Perozo, E. (deposition date: 2010-11-10, release date: 2011-07-06, Last modification date: 2024-11-20)

Primary citation

Uysal, S.,Cuello, L.G.,Cortes, D.M.,Koide, S.,Kossiakoff, A.A.,Perozo, E.
Mechanism of activation gating in the full-length KcsA K+ channel.
Proc.Natl.Acad.Sci.USA, 108:11896-11899, 2011

PubMed Abstract: Using a constitutively active channel mutant, we solved the structure of full-length KcsA in the open conformation at 3.9 Å. The structure reveals that the activation gate expands about 20 Å, exerting a strain on the bulge helices in the C-terminal domain and generating side windows large enough to accommodate hydrated K(+) ions. Functional and spectroscopic analysis of the gating transition provides direct insight into the allosteric coupling between the activation gate and the selectivity filter. We show that the movement of the inner gate helix is transmitted to the C-terminus as a straightforward expansion, leading to an upward movement and the insertion of the top third of the bulge helix into the membrane. We suggest that by limiting the extent to which the inner gate can open, the cytoplasmic domain also modulates the level of inactivation occurring at the selectivity filter.

PubMed: 21730186
DOI: 10.1073/pnas.1105112108

Experimental method

X-RAY DIFFRACTION (3.8 Å)