Structural highlights
4ntx is a 3 chain structure with sequence from Chick and Mictn. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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| Ligands: | AMR, CL, NA, NAG, P6G |
| NonStd Res: | PCA |
| Related: | 3hgc, 2qts, 4ntw, 4nyk, 4nty, 4fz0 |
| Gene: | ASIC1, ACCN2 (CHICK) |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
[ASIC1_CHICK] Cation channel with high affinity for sodium, which is gated by extracellular protons and inhibited by the diuretic amiloride (By similarity).[1]
Publication Abstract from PubMed
Acid-sensing ion channels (ASICs) detect extracellular protons produced during inflammation or ischemic injury and belong to the superfamily of degenerin/epithelial sodium channels. Here, we determine the cocrystal structure of chicken ASIC1a with MitTx, a pain-inducing toxin from the Texas coral snake, to define the structure of the open state of ASIC1a. In the MitTx-bound open state and in the previously determined low-pH desensitized state, TM2 is a discontinuous alpha helix in which the Gly-Ala-Ser selectivity filter adopts an extended, belt-like conformation, swapping the cytoplasmic one-third of TM2 with an adjacent subunit. Gly 443 residues of the selectivity filter provide a ring of three carbonyl oxygen atoms with a radius of approximately 3.6 A, presenting an energetic barrier for hydrated ions. The ASIC1a-MitTx complex illuminates the mechanism of MitTx action, defines the structure of the selectivity filter of voltage-independent, sodium-selective ion channels, and captures the open state of an ASIC.
X-ray structure of Acid-sensing ion channel 1-snake toxin complex reveals open state of a na(+)-selective channel.,Baconguis I, Bohlen CJ, Goehring A, Julius D, Gouaux E Cell. 2014 Feb 13;156(4):717-29. doi: 10.1016/j.cell.2014.01.011. Epub 2014 Feb, 6. PMID:24507937[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Coric T, Zheng D, Gerstein M, Canessa CM. Proton sensitivity of ASIC1 appeared with the rise of fishes by changes of residues in the region that follows TM1 in the ectodomain of the channel. J Physiol. 2005 Nov 1;568(Pt 3):725-35. Epub 2005 Jul 7. PMID:16002453 doi:https://dx.doi.org/jphysiol.2005.087734
- ↑ Baconguis I, Bohlen CJ, Goehring A, Julius D, Gouaux E. X-ray structure of Acid-sensing ion channel 1-snake toxin complex reveals open state of a na(+)-selective channel. Cell. 2014 Feb 13;156(4):717-29. doi: 10.1016/j.cell.2014.01.011. Epub 2014 Feb, 6. PMID:24507937 doi:https://dx.doi.org/10.1016/j.cell.2014.01.011
