EMDB/PDB/SASBDBから引用されている文献のデータベース

キーワード
構造解析手法	All X線回折 NMR 電子顕微鏡小角散乱中性子線回折線維回折粉末回折赤外分光 EPR FRET 理論モデルハイブリッド
著者・登録者
ジャーナル
IF	>30 >20 >10 >5 all

タイトル	Conformation space of a heterodimeric ABC exporter under turnover conditions.
ジャーナル・号・ページ	Nature, Vol. 571, Issue 7766, Page 580-583, Year 2019
掲載日	2019年7月17日
著者	Susanne Hofmann / Dovile Januliene / Ahmad R Mehdipour / Christoph Thomas / Erich Stefan / Stefan Brüchert / Benedikt T Kuhn / Eric R Geertsma / Gerhard Hummer / Robert Tampé / Arne Moeller /
PubMed 要旨	Cryo-electron microscopy (cryo-EM) has the capacity to capture molecular machines in action. ATP-binding cassette (ABC) exporters are highly dynamic membrane proteins that extrude a wide range of ...Cryo-electron microscopy (cryo-EM) has the capacity to capture molecular machines in action. ATP-binding cassette (ABC) exporters are highly dynamic membrane proteins that extrude a wide range of substances from the cytosol and thereby contribute to essential cellular processes, adaptive immunity and multidrug resistance. Despite their importance, the coupling of nucleotide binding, hydrolysis and release to the conformational dynamics of these proteins remains poorly resolved, especially for heterodimeric and/or asymmetric ABC exporters that are abundant in humans. Here we present eight high-resolution cryo-EM structures that delineate the full functional cycle of an asymmetric ABC exporter in a lipid environment. Cryo-EM analysis under active turnover conditions reveals distinct inward-facing (IF) conformations-one of them with a bound peptide substrate-and previously undescribed asymmetric post-hydrolysis states with dimerized nucleotide-binding domains and a closed extracellular gate. By decreasing the rate of ATP hydrolysis, we could capture an outward-facing (OF) open conformation-an otherwise transient state vulnerable to substrate re-entry. The ATP-bound pre-hydrolysis and vanadate-trapped states are conformationally equivalent; both comprise co-existing OF conformations with open and closed extracellular gates. By contrast, the post-hydrolysis states from the turnover experiment exhibit asymmetric ATP and ADP occlusion after phosphate release from the canonical site and display a progressive separation of the nucleotide-binding domains and unlocking of the intracellular gate. Our findings reveal that phosphate release, not ATP hydrolysis, triggers the return of the exporter to the IF conformation. By mapping the conformational landscape during active turnover, aided by mutational and chemical modulation of kinetic rates to trap the key intermediates, we resolved fundamental steps of the substrate translocation cycle of asymmetric ABC transporters.
リンク	Nature / PubMed:31316210 / PubMed Central
手法	EM (単粒子)
解像度	2.8 - 4.2 Å
構造データ	4773 6raf EMDB-4773, PDB-6raf: Heterodimeric ABC exporter TmrAB in inward-facing narrow conformation under turnover conditions 手法: EM (単粒子) / 解像度: 3.8 Å 4774 6rag EMDB-4774, PDB-6rag: Heterodimeric ABC exporter TmrAB in inward-facing wide conformation under turnover conditions 手法: EM (単粒子) / 解像度: 4.2 Å 4775 6rah EMDB-4775, PDB-6rah: Heterodimeric ABC exporter TmrAB in ATP-bound outward-facing open conformation 手法: EM (単粒子) / 解像度: 2.8 Å 4776 6rai EMDB-4776, PDB-6rai: Heterodimeric ABC exporter TmrAB in ATP-bound outward-facing occluded conformation 手法: EM (単粒子) / 解像度: 2.9 Å 4777 6raj EMDB-4777, PDB-6raj: Heterodimeric ABC exporter TmrAB in vanadate trapped outward-facing open conformation 手法: EM (単粒子) / 解像度: 3.5 Å 4778 6rak EMDB-4778, PDB-6rak: Heterodimeric ABC exporter TmrAB in vanadate trapped outward-facing occluded conformation 手法: EM (単粒子) / 解像度: 3.3 Å 4779 6ral EMDB-4779, PDB-6ral: Heterodimeric ABC exporter TmrAB under turnover conditions in asymmetric unlocked return conformation 手法: EM (単粒子) / 解像度: 3.5 Å 4780 6ram EMDB-4780, PDB-6ram: Heterodimeric ABC exporter TmrAB under turnover conditions in asymmetric unlocked return conformation with wider opened intracellular gate 手法: EM (単粒子) / 解像度: 3.8 Å 4781 6ran EMDB-4781: Heterodimeric ABC exporter TmrAB with bound peptide substrate in inward-facing wide conformation PDB-6ran: Heterodimeric ABC exporter TmrAB in inward-facing wide conformation 手法: EM (単粒子) / 解像度: 4.2 Å
化合物	ChemComp-ATP: ADENOSINE-5'-TRIPHOSPHATE / ATP / ATP, エネルギー貯蔵分子YM / アデノシン三リン酸 ChemComp-ADP: ADENOSINE-5'-DIPHOSPHATE / ADP / ADP, エネルギー貯蔵分子YM / アデノシン二リン酸 ChemComp-MG: Unknown entry / マグネシウムジカチオン ChemComp-HOH: WATER / 水 ChemComp-AOV: ADP ORTHOVANADATE / エネルギー貯蔵分子類似体*YM
由来	thermus thermophilus hb27 (サーマス・サーモフィルス) thermus thermophilus (サーマス・サーモフィルス) vicugna pacos (アルパカ)
キーワード	TRANSPORT PROTEIN (運搬体タンパク質) / ATP-binding cassette transporter / membrane protein (膜タンパク質) / heterodimer / exporter / ABC transporter / nucleotide binding domains