Download MendeleyCryo-EM structure of human Cx31.3/GJC3 connexin hemichannel.
Lee, H.J., Jeong, H., Hyun, J., Ryu, B., Park, K., Lim, H.H., Yoo, J., Woo, J.S.(2020) Sci Adv 6: eaba4996-eaba4996
- PubMed: 32923625
- DOI: https://doi.org/10.1126/sciadv.aba4996
- Primary Citation of Related Structures:
6L3T, 6L3U, 6L3V - 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.
Organizational Affiliation:
Department of Life Sciences, Korea University, Seoul 02841, Republic of Korea.
