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.
Excitatoryaminoacidtransporter3 / Excitatory amino-acid carrier 1 / Neuronal and epithelial glutamate transporter / Sodium-dependent ...Excitatory amino-acid carrier 1 / Neuronal and epithelial glutamate transporter / Sodium-dependent glutamate/aspartate transporter 3 / Solute carrier family 1 member 1
分子量: 57275.168 Da / 分子数: 3 / 変異: N178T, N195T / 由来タイプ: 組換発現 詳細: The Glycine and Proline at the N terminal are the residues left after PreScission Protease treatment 由来: (組換発現) Homo sapiens (ヒト) / 遺伝子: SLC1A1, EAAC1, EAAT3 / 発現宿主: Homo sapiens (ヒト) / 参照: UniProt: P43005
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実験情報
-
実験
実験
手法: 電子顕微鏡法
EM実験
試料の集合状態: PARTICLE / 3次元再構成法: 単粒子再構成法
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試料調製
構成要素
ID
名称
タイプ
Entity ID
Parent-ID
由来
1
inwardfacinghEAAT3trimer
COMPLEX
all
0
RECOMBINANT
2
inwardfacinghEAAT3trimer
COMPLEX
all
1
RECOMBINANT
由来(天然)
ID
Entity assembly-ID
生物種
Ncbi tax-ID
2
1
Homo sapiens (ヒト)
9606
3
2
Homo sapiens (ヒト)
9606
由来(組換発現)
ID
Entity assembly-ID
生物種
Ncbi tax-ID
2
1
Homo sapiens (ヒト)
9606
3
2
Homo sapiens (ヒト)
9606
緩衝液
pH: 8
緩衝液成分
ID
濃度
名称
式
Buffer-ID
1
20mM
Tris
C4H11NO3
1
2
200mM
SodiumChloride
NaCl
1
3
1mM
L-Aspartate
C4H7NO4
1
4
1mM
TCEP
C9H15O6P
1
5
0.086mM
DigitoninGlycoDiosgenin
C56H92O25
1
試料
濃度: 6 mg/ml / 包埋: NO / シャドウイング: NO / 染色: NO / 凍結: YES / 詳細: This sample was mono disperse