National Institutes of Health/National Institute of Neurological Disorders and Stroke (NIH/NINDS)
R01NS064357
米国
引用
ジャーナル: Sci Adv / 年: 2021 タイトル: Cryo-EM structures of excitatory amino acid transporter 3 visualize coupled substrate, sodium, and proton binding and transport. 著者: Biao Qiu / Doreen Matthies / Eva Fortea / Zhiheng Yu / Olga Boudker / 要旨: Human excitatory amino acid transporter 3 (hEAAT3) mediates glutamate uptake in neurons, intestine, and kidney. Here, we report cryo-EM structures of hEAAT3 in several functional states where the ...Human excitatory amino acid transporter 3 (hEAAT3) mediates glutamate uptake in neurons, intestine, and kidney. Here, we report cryo-EM structures of hEAAT3 in several functional states where the transporter is empty, bound to coupled sodium ions only, or fully loaded with three sodium ions, a proton, and the substrate aspartate. The structures suggest that hEAAT3 operates by an elevator mechanism involving three functionally independent subunits. When the substrate-binding site is near the cytoplasm, it has a remarkably low affinity for the substrate, perhaps facilitating its release and allowing the rapid transport turnover. The mechanism of the coupled uptake of the sodium ions and the substrate is conserved across evolutionarily distant families and is augmented by coupling to protons in EAATs. The structures further suggest a mechanism by which a conserved glutamate residue mediates proton symport.
タンパク質・ペプチド: human Excitatory amino acid transporter 3
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超分子 #1: inward facing hEAAT3 trimer in 10mM Glu
超分子
名称: inward facing hEAAT3 trimer in 10mM Glu / タイプ: complex / ID: 1 / 親要素: 0 / 含まれる分子: all
由来(天然)
生物種: Homo sapiens (ヒト)
組換発現
生物種: Homo sapiens (ヒト)
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超分子 #2: inward facing hEAAT3 trimer in 10mM Glu
超分子
名称: inward facing hEAAT3 trimer in 10mM Glu / タイプ: complex / ID: 2 / 親要素: 1 / 含まれる分子: all
由来(天然)
生物種: Homo sapiens (ヒト)
組換発現
生物種: Homo sapiens (ヒト)
-
分子 #1: human Excitatory amino acid transporter 3
分子
名称: human Excitatory amino acid transporter 3 / タイプ: protein_or_peptide / ID: 1 詳細: The Glycine and Proline at the N terminal are the residues left after PreScission Protease treatment 光学異性体: LEVO