3IJ4

Cesium sites in the crystal structure of a functional acid sensing ion channel in the desensitized state

Summary for 3IJ4

• Entry DOI: 10.2210/pdb3ij4/pdb
• Related: 3HGC
• Descriptor: Amiloride-sensitive cation channel 2, neuronal, CHLORIDE ION, CESIUM ION, ... (4 entities in total)
• Functional Keywords: acid-sensing, functional, ion channel, trimer, membrane protein, sodium channel, cell membrane, glycoprotein, ion transport, ionic channel, membrane, sodium, sodium transport, transmembrane, transport, transport protein, cesium, anomalous
• Biological source: Gallus gallus (bantam,chickens)
• Cellular location: Cell membrane; Multi-pass membrane protein (Probable): Q1XA76
• Total number of polymer chains: 1
• Total formula weight: 53659.39

Authors

Gonzales, E.B.,Gouaux, E. (deposition date: 2009-08-03, release date: 2009-11-10, Last modification date: 2011-07-13)

Primary citation

Gonzales, E.B.,Kawate, T.,Gouaux, E.
Pore architecture and ion sites in acid-sensing ion channels and P2X receptors.
Nature, 460:599-604, 2009

PubMed Abstract: Acid-sensing ion channels are proton-activated, sodium-selective channels composed of three subunits, and are members of the superfamily of epithelial sodium channels, mechanosensitive and FMRF-amide peptide-gated ion channels. These ubiquitous eukaryotic ion channels have essential roles in biological activities as diverse as sodium homeostasis, taste and pain. Despite their crucial roles in biology and their unusual trimeric subunit stoichiometry, there is little knowledge of the structural and chemical principles underlying their ion channel architecture and ion-binding sites. Here we present the structure of a functional acid-sensing ion channel in a desensitized state at 3 A resolution, the location and composition of the approximately 8 A 'thick' desensitization gate, and the trigonal antiprism coordination of caesium ions bound in the extracellular vestibule. Comparison of the acid-sensing ion channel structure with the ATP-gated P2X(4) receptor reveals similarity in pore architecture and aqueous vestibules, suggesting that there are unanticipated yet common structural and mechanistic principles.

PubMed: 19641589
DOI: 10.1038/nature08218

Experimental method

X-RAY DIFFRACTION (3 Å)