6LYG

Cryo-EM structure of the calcium homeostasis modulator 1 channel

Summary for 6LYG

• Entry DOI: 10.2210/pdb6lyg/pdb
• EMDB information: 30016
• Descriptor: Calcium homeostasis modulator 1, 2-acetamido-2-deoxy-beta-D-glucopyranose (2 entities in total)
• Functional Keywords: octamer, membrane protein
• Biological source: Danio rerio (Zebrafish)
• Total number of polymer chains: 8
• Total formula weight: 331478.82

Authors

Ren, Y.,Yang, X.,Shen, Y. (deposition date: 2020-02-14, release date: 2020-10-07, Last modification date: 2024-10-23)

Primary citation

Ren, Y.,Wen, T.,Xi, Z.,Li, S.,Lu, J.,Zhang, X.,Yang, X.,Shen, Y.
Cryo-EM structure of the calcium homeostasis modulator 1 channel.
Sci Adv, 6:eaba8161-eaba8161, 2020

PubMed Abstract: Calcium homeostasis modulator 1 (CALHM1) is a voltage-gated ATP release channel that plays an important role in neural gustatory signaling and the pathogenesis of Alzheimer's disease. Here, we present a cryo-electron microscopy structure of full-length Ca-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.

PubMed: 32832630
DOI: 10.1126/sciadv.aba8161

Experimental method

ELECTRON MICROSCOPY (3.1 Å)