National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
米国
Welch Foundation
米国
Damon Runyon Cancer Research Foundation
米国
引用
ジャーナル: Proc Natl Acad Sci U S A / 年: 2021 タイトル: Molecular basis of cholesterol efflux via ABCG subfamily transporters. 著者: Yingyuan Sun / Jin Wang / Tao Long / Xiaofeng Qi / Linda Donnelly / Nadia Elghobashi-Meinhardt / Leticia Esparza / Jonathan C Cohen / Xiao-Song Xie / Helen H Hobbs / Xiaochun Li / 要旨: The ABCG1 homodimer (G1) and ABCG5-ABCG8 heterodimer (G5G8), two members of the adenosine triphosphate (ATP)-binding cassette (ABC) transporter G family, are required for maintenance of cellular ...The ABCG1 homodimer (G1) and ABCG5-ABCG8 heterodimer (G5G8), two members of the adenosine triphosphate (ATP)-binding cassette (ABC) transporter G family, are required for maintenance of cellular cholesterol levels. G5G8 mediates secretion of neutral sterols into bile and the gut lumen, whereas G1 transports cholesterol from macrophages to high-density lipoproteins (HDLs). The mechanisms used by G5G8 and G1 to recognize and export sterols remain unclear. Here, we report cryoelectron microscopy (cryo-EM) structures of human G5G8 in sterol-bound and human G1 in cholesterol- and ATP-bound states. Both transporters have a sterol-binding site that is accessible from the cytosolic leaflet. A second site is present midway through the transmembrane domains of G5G8. The Walker A motif of G8 adopts a unique conformation that accounts for the marked asymmetry in ATPase activities between the two nucleotide-binding sites of G5G8. These structures, along with functional validation studies, provide a mechanistic framework for understanding cholesterol efflux via ABC transporters.
The antibody was cleaved with papain to generate the Fab fragments. It is uncertain where papain ...The antibody was cleaved with papain to generate the Fab fragments. It is uncertain where papain cleaved, and not all of the Fab is visible in the map. The sequence provided for the heavy chain represents a possible sequence; however, the C-terminal end is uncertain.
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実験情報
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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
ABCG1transporterwithFab2C7
COMPLEX
all
0
MULTIPLESOURCES
2
ABCG5/ABCG8transporter
COMPLEX
#1-#2
1
RECOMBINANT
3
2C7Fab
COMPLEX
#3-#4
1
RECOMBINANT
分子量
値: 0.15 MDa / 実験値: NO
由来(天然)
ID
Entity assembly-ID
生物種
Ncbi tax-ID
2
2
Homo sapiens (ヒト)
9606
3
3
Mus musculus (ハツカネズミ)
10090
由来(組換発現)
ID
Entity assembly-ID
生物種
Ncbi tax-ID
2
2
Homo sapiens (ヒト)
9606
3
3
Mus musculus (ハツカネズミ)
10090
緩衝液
pH: 7.5
試料
濃度: 10 mg/ml / 包埋: NO / シャドウイング: NO / 染色: NO / 凍結: YES 詳細: Added 8mM ATP, Magnesium and 0.2mg/ml cholesterol in ethanol
急速凍結
装置: FEI VITROBOT MARK IV / 凍結剤: ETHANE / 湿度: 100 % / 凍結前の試料温度: 293 K