3U6N

Open Structure of the BK channel Gating Ring

Summary for 3U6N

• Entry DOI: 10.2210/pdb3u6n/pdb
• Descriptor: High-Conductance Ca2+-Activated K+ Channel protein, CALCIUM ION (2 entities in total)
• Functional Keywords: potassium channel, transport protein
• Biological source: Danio rerio (Zebrafish); More
• Total number of polymer chains: 8
• Total formula weight: 629833.50

Authors

Yuan, P.,MacKinnon, R. (deposition date: 2011-10-12, release date: 2011-12-07, Last modification date: 2024-02-28)

Primary citation

Yuan, P.,Leonetti, M.D.,Hsiung, Y.,Mackinnon, R.
Open structure of the Ca(2+) gating ring in the high-conductance Ca(2+)-activated K(+) channel.
Nature, 481:94-97, 2011

PubMed Abstract: High-conductance voltage- and Ca(2+)-activated K(+) channels function in many physiological processes that link cell membrane voltage and intracellular Ca(2+) concentration, including neuronal electrical activity, skeletal and smooth muscle contraction, and hair cell tuning. Like other voltage-dependent K(+) channels, Ca(2+)-activated K(+) channels open when the cell membrane depolarizes, but in contrast to other voltage-dependent K(+) channels, they also open when intracellular Ca(2+) concentrations rise. Channel opening by Ca(2+) is made possible by a structure called the gating ring, which is located in the cytoplasm. Recent structural studies have defined the Ca(2+)-free, closed, conformation of the gating ring, but the Ca(2+)-bound, open, conformation is not yet known. Here we present the Ca(2+)-bound conformation of the gating ring. This structure shows how one layer of the gating ring, in response to the binding of Ca(2+), opens like the petals of a flower. The degree to which it opens explains how Ca(2+) binding can open the transmembrane pore. These findings present a molecular basis for Ca(2+) activation of K(+) channels and suggest new possibilities for targeting the gating ring to treat conditions such as asthma and hypertension.

PubMed: 22139424
DOI: 10.1038/nature10670

Experimental method

X-RAY DIFFRACTION (3.61 Å)