2X6B

Potassium Channel from Magnetospirillum Magnetotacticum

Summary for 2X6B

• Entry DOI: 10.2210/pdb2x6b/pdb
• Related: 1XL4 1XL6 2WLH 2WLI 2WLJ 2WLK 2WLL 2WLM 2WLN 2WLO 2X6A 2X6C
• Descriptor: ATP-SENSITIVE INWARD RECTIFIER POTASSIUM CHANNEL 10, BARIUM ION, POTASSIUM ION, ... (5 entities in total)
• Functional Keywords: ion channel, metal transport, integral membrane protein
• Biological source: MAGNETOSPIRILLUM MAGNETOTACTICUM
• Total number of polymer chains: 1
• Total formula weight: 34164.49

Authors

Clarke, O.B.,Caputo, A.T.,Hill, A.P.,Vandenberg, J.I.,Smith, B.J.,Gulbis, J.M. (deposition date: 2010-02-15, release date: 2010-06-23, Last modification date: 2023-12-20)

Primary citation

Clarke, O.B.,Caputo, A.T.,Hill, A.P.,Vandenberg, J.I.,Smith, B.J.,Gulbis, J.M.
Domain Reorientation and Rotation of an Intracellular Assembly Regulate Conduction in Kir Potassium Channels.
Cell(Cambridge,Mass.), 141:1018-, 2010

PubMed Abstract: Potassium channels embedded in cell membranes employ gates to regulate K+ current. While a specific constriction in the permeation pathway has historically been implicated in gating, recent reports suggest that the signature ion selectivity filter located in the outer membrane leaflet may be equally important. Inwardly rectifying K+ channels also control the directionality of flow, using intracellular polyamines to stem ion efflux by a valve-like action. This study presents crystallographic evidence of interdependent gates in the conduction pathway and reveals the mechanism of polyamine block. Reorientation of the intracellular domains, concomitant with activation, instigates polyamine release from intracellular binding sites to block the permeation pathway. Conformational adjustments of the slide helices, achieved by rotation of the cytoplasmic assembly relative to the pore, are directly correlated to the ion configuration in the selectivity filter. Ion redistribution occurs irrespective of the constriction, suggesting a more expansive role of the selectivity filter in gating than previously appreciated.

PubMed: 20564790
DOI: 10.1016/J.CELL.2010.05.003

Experimental method

X-RAY DIFFRACTION (3.3 Å)