6c5w
From Proteopedia
Crystal structure of the mitochondrial calcium uniporter
Structural highlights
FunctionMCU_METAQ Highly selective calcium channel localized to the inner mitochondrial membrane, which mediates calcium uptake into the mitochondrial matrix (PubMed:29995856). Mitochondrial calcium homeostasis plays key roles in cellular physiology and regulates ATP production, cytoplasmic calcium signals and activation of cell death pathways (PubMed:29995856). Sufficient to operate as a pore-forming channel without the need of calcium-sensor or auxiliary subunit (PubMed:29995856).[1] Publication Abstract from PubMedMitochondrial calcium uptake is critical for regulating ATP production, intracellular calcium signalling, and cell death. This uptake is mediated by a highly selective calcium channel called the mitochondrial calcium uniporter (MCU). Here, we determined the structures of the pore-forming MCU proteins from two fungi by X-ray crystallography and single-particle cryo-electron microscopy. The stoichiometry, overall architecture, and individual subunit structure differed markedly from those described in the recent nuclear magnetic resonance structure of Caenorhabditis elegans MCU. We observed a dimer-of-dimer architecture across species and chemical environments, which was corroborated by biochemical experiments. Structural analyses and functional characterization uncovered the roles of key residues in the pore. These results reveal a new ion channel architecture, provide insights into calcium coordination, selectivity and conduction, and establish a structural framework for understanding the mechanism of mitochondrial calcium uniporter function. X-ray and cryo-EM structures of the mitochondrial calcium uniporter.,Fan C, Fan M, Orlando BJ, Fastman NM, Zhang J, Xu Y, Chambers MG, Xu X, Perry K, Liao M, Feng L Nature. 2018 Jul 11. pii: 10.1038/s41586-018-0330-9. doi:, 10.1038/s41586-018-0330-9. PMID:29995856[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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