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-Structure paper
Title | Cryo-EM structure of human Cx31.3/GJC3 connexin hemichannel. |
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Journal, issue, pages | Sci Adv, Vol. 6, Issue 35, Page eaba4996, Year 2020 |
Publish date | Aug 28, 2020 |
Authors | Hyuk-Joon Lee / Hyeongseop Jeong / Jaekyung Hyun / Bumhan Ryu / Kunwoong Park / Hyun-Ho Lim / Jejoong Yoo / Jae-Sung Woo / |
PubMed Abstract | Connexin family proteins assemble into hexameric channels called hemichannels/connexons, which function as transmembrane channels or dock together to form gap junction intercellular channels (GJIChs). ...Connexin family proteins assemble into hexameric channels called hemichannels/connexons, which function as transmembrane channels or dock together to form gap junction intercellular channels (GJIChs). We determined the cryo-electron microscopy structures of human connexin 31.3 (Cx31.3)/GJC3 hemichannels in the presence and absence of calcium ions and with a hearing-loss mutation R15G at 2.3-, 2.5-, and 2.6-Å resolutions, respectively. Compared with available structures of GJICh in open conformation, Cx31.3 hemichannel shows substantial structural changes of highly conserved regions in the connexin family, including opening of calcium ion-binding tunnels, reorganization of salt-bridge networks, exposure of lipid-binding sites, and collocation of amino-terminal helices at the cytoplasmic entrance. We also found that the hemichannel has a pore with a diameter of ~8 Å and selectively transports chloride ions. Our study provides structural insights into the permeant selectivity of Cx31.3 hemichannel. |
External links | Sci Adv / PubMed:32923625 / PubMed Central |
Methods | EM (single particle) |
Resolution | 2.34 - 2.63 Å |
Structure data | EMDB-0825, PDB-6l3t: |
Chemicals | ChemComp-LMN: ChemComp-HOH: ChemComp-CA: |
Source |
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Keywords | MEMBRANE PROTEIN / Gap junction / Hemichannel / Hexamer / ATP release |