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-Structure paper
Title | Cryo-EM structure of a proton-activated chloride channel TMEM206. |
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Journal, issue, pages | Sci Adv, Vol. 7, Issue 9, Year 2021 |
Publish date | Feb 24, 2021 |
Authors | Zengqin Deng / Yonghui Zhao / Jing Feng / Jingying Zhang / Haiyan Zhao / Michael J Rau / James A J Fitzpatrick / Hongzhen Hu / Peng Yuan / |
PubMed Abstract | TMEM206 has been recently identified as an evolutionarily conserved chloride channel that underlies ubiquitously expressed, proton-activated, outwardly rectifying anion currents. Here, we report the ...TMEM206 has been recently identified as an evolutionarily conserved chloride channel that underlies ubiquitously expressed, proton-activated, outwardly rectifying anion currents. Here, we report the cryo-electron microscopy structure of pufferfish TMEM206, which forms a trimeric channel, with each subunit comprising two transmembrane segments and a large extracellular domain. An ample vestibule in the extracellular region is accessible laterally from the three side portals. The central pore contains multiple constrictions. A conserved lysine residue near the cytoplasmic end of the inner helix forms the presumed chloride ion selectivity filter. Unprecedentedly, the core structure and assembly closely resemble those of the epithelial sodium channel/degenerin family of sodium channels that are unrelated in amino acid sequence and conduct cations instead of anions. Together with electrophysiology, this work provides insights into ion conduction and gating for a new class of chloride channels that is architecturally distinct from previously characterized chloride channel families. |
External links | Sci Adv / PubMed:33627432 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.46 - 6.17 Å |
Structure data | EMDB-22342: EMDB-22343, PDB-7ji3: |
Source |
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Keywords | TRANSPORT PROTEIN / ion channel |