PUBLICATION

Cryo-EM structures of fungal and metazoan mitochondrial calcium uniporters

Authors
Baradaran, R., Wang, C., Siliciano, A.F., Long, S.B.
ID
ZDB-PUB-180713-9
Date
2018
Source
Nature   559(7715): 580-584 (Journal)
Registered Authors
Keywords
none
MeSH Terms
  • Calcium Channels/chemistry*
  • Calcium Channels/metabolism
  • Calcium Channels/ultrastructure*
  • Caenorhabditis elegans/chemistry
  • Ion Channel Gating
  • Cryoelectron Microscopy*
  • Calcium/metabolism
  • Zebrafish*
  • Protein Subunits/chemistry
  • Protein Subunits/metabolism
  • Models, Molecular
  • Phialophora/chemistry*
  • Protein Multimerization
  • Animals
PubMed
29995857 Full text @ Nature
Abstract
The mitochondrial calcium uniporter (MCU) is a highly selective calcium channel and a major route of calcium entry into mitochondria. How the channel catalyses ion permeation and achieves ion selectivity are not well understood, partly because MCU is thought to have a distinct architecture in comparison to other cellular channels. Here we report cryo-electron microscopy reconstructions of MCU channels from zebrafish and Cyphellophora europaea at 8.5 Ć and 3.2 Ć resolutions, respectively. In contrast to a previous report of pentameric stoichiometry for MCU, both channels are tetramers. The atomic model of C. europaea MCU shows that a conserved WDXXEP signature sequence forms the selectivity filter, in which calcium ions are arranged in single file. Coiled-coil legs connect the pore to N-terminal domains in the mitochondrial matrix. In C. europaea MCU, the N-terminal domains assemble as a dimer of dimers; in zebrafish MCU, they form an asymmetric crescent. The structures define principles that underlie ion permeation and calcium selectivity in this unusual channel.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping