1JQ1

POTASSIUM CHANNEL (KCSA) OPEN GATE MODEL

Summary for 1JQ1

• Entry DOI: 10.2210/pdb1jq1/pdb
• Related: 1JQ2
• Descriptor: VOLTAGE-GATED POTASSIUM CHANNEL (1 entity in total)
• Functional Keywords: potassium channel, integral membrane protein, open state, membrane protein
• Biological source: Streptomyces lividans
• Cellular location: Cell membrane; Multi-pass membrane protein: P0A334
• Total number of polymer chains: 4
• Total formula weight: 14445.13

Authors

Liu, Y.-S.,Sompornpisut, P.,Perozo, E. (deposition date: 2001-08-03, release date: 2001-10-03, Last modification date: 2024-05-22)

Primary citation

Liu, Y.S.,Sompornpisut, P.,Perozo, E.
Structure of the KcsA channel intracellular gate in the open state.
Nat.Struct.Biol., 8:883-887, 2001

PubMed Abstract: Ion channels catalyze the selective transfer of ions across the membrane in response to a variety of stimuli. These channels gate by controlling the access of ions to a centrally located water-filled pore. The crystal structure of the Streptomyces lividans potassium channel (KcsA) has allowed a molecular exploration of this mechanism. Electron paramagnetic resonance (EPR) studies have uncovered significant conformational changes at the intracellular end of the second transmembrane helix (TM2) upon gating. We have used site-directed spin labeling (SDSL) and EPR spectroscopy in an attempt to quantify the structural rearrangements of the KcsA TM2 bundle underlying the transition from the closed to the open state. Under conditions favoring the closed and open conformations, 10 intersubunit distances were obtained across TM2 segments from tandem dimer constructs. Analysis of these data points to a mechanism in which each TM2 helix tilts away from the permeation pathway, towards the membrane plane, and rotates about its helical axis, supporting a scissoring-type motion with a pivot point near residues 107-108. These movements are accompanied by a large increase in the diameter of the vestibule below the central water-filled cavity.

PubMed: 11573095
DOI: 10.1038/nsb1001-883

Experimental method

SOLUTION NMR