6L3U

Human Cx31.3/GJC3 connexin hemichannel in the presence of calcium

Summary for 6L3U

• Entry DOI: 10.2210/pdb6l3u/pdb
• EMDB information: 0826
• Descriptor: Gap junction gamma-3 protein, Lauryl Maltose Neopentyl Glycol, CALCIUM ION, ... (4 entities in total)
• Functional Keywords: gap junction, hemichannel, hexamer, atp release, membrane protein
• Biological source: Homo sapiens (Human)
• Total number of polymer chains: 6
• Total formula weight: 194307.79

Authors

Lee, H.J.,Jeong, H.,Ryu, B.,Hyun, J.,Woo, J.S. (deposition date: 2019-10-15, release date: 2020-09-09, Last modification date: 2024-11-13)

Primary citation

Lee, H.J.,Jeong, H.,Hyun, J.,Ryu, B.,Park, K.,Lim, H.H.,Yoo, J.,Woo, J.S.
Cryo-EM structure of human Cx31.3/GJC3 connexin hemichannel.
Sci Adv, 6:eaba4996-eaba4996, 2020

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). 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.

PubMed: 32923625
DOI: 10.1126/sciadv.aba4996

Experimental method

ELECTRON MICROSCOPY (2.53 Å)