3EFF

The Crystal Structure of Full-Length KcsA in its Closed Conformation

Summary for 3EFF

• Entry DOI: 10.2210/pdb3eff/pdb
• Descriptor: FAB, Voltage-gated potassium channel (3 entities in total)
• Functional Keywords: full length kcsa, bulge helix, cell membrane, ion transport, ionic channel, membrane, transmembrane, transport, voltage-gated channel, membrane protein
• Biological source: Mus musculus; More
• Cellular location: Cell membrane; Multi-pass membrane protein: 3EFF
• Total number of polymer chains: 8
• Total formula weight: 156632.25

Authors

Uysal, S.,Vasquez, V.,Tereshko, T.,Esaki, K.,Fellouse, F.A.,Sidhu, S.S.,Koide, S.,Perozo, E.,Kossiakoff, A. (deposition date: 2008-09-08, release date: 2009-04-14, Last modification date: 2011-07-13)

Primary citation

Uysal, S.,Vasquez, V.,Tereshko, V.,Esaki, K.,Fellouse, F.A.,Sidhu, S.S.,Koide, S.,Perozo, E.,Kossiakoff, A.
Crystal structure of full-length KcsA in its closed conformation.
Proc.Natl.Acad.Sci.USA, 106:6644-6649, 2009

PubMed Abstract: KcsA is a proton-activated, voltage-modulated K(+) channel that has served as the archetype pore domain in the Kv channel superfamily. Here, we have used synthetic antigen-binding fragments (Fabs) as crystallographic chaperones to determine the structure of full-length KcsA at 3.8 A, as well as that of its isolated C-terminal domain at 2.6 A. The structure of the full-length KcsA-Fab complex reveals a well-defined, 4-helix bundle that projects approximately 70 A toward the cytoplasm. This bundle promotes a approximately 15 degree bending in the inner bundle gate, tightening its diameter and shifting the narrowest point 2 turns of helix below. Functional analysis of the full-length KcsA-Fab complex suggests that the C-terminal bundle remains whole during gating. We suggest that this structure likely represents the physiologically relevant closed conformation of KcsA.

PubMed: 19346472
DOI: 10.1073/pnas.0810663106

Experimental method

X-RAY DIFFRACTION (3.8 Å)