Cryo-EM structure of the calcium homeostasis modulator 1 channel

作者：Yue Ren, Tianlei Wen, Zhiqin Xi, Shunjin Li, Jing Lu, Xing Zhang, Xue Yang, Yuequan Shen · 发表于：Science Advances · 年份：2020 · DOI：10.1126/sciadv.aba8161 · 被引用次数：27 · 研究领域：Ion channel regulation and function、Neuroscience and Neuropharmacology Research、Lipid Membrane Structure and Behavior

-free CALHM1 from Danio rerio at an overall resolution of 3.1 Å. Our structure reveals an octameric architecture with a wide pore diameter of ~20 Å, presumably representing the active conformation. The overall structure is substantially different from that of the isoform CALHM2, which forms both undecameric hemichannels and gap junctions. The N-terminal small helix folds back to the pore and forms an antiparallel interaction with transmembrane helix 1. Structural analysis revealed that the extracellular loop 1 region within the dimer interface may contribute to oligomeric assembly. A positive potential belt inside the pore was identified that may modulate ion permeation. Our structure offers insights into the assembly and gating mechanism of the CALHM1 channel.