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	Conformational Changes of the Escherichia coli Serine Chemoreceptor in Different Signaling States.
ジャーナル・号・ページ	mBio, Vol. 10, Issue 4, Year 2019
掲載日	2019年7月2日
著者	Wen Yang / C Keith Cassidy / Peter Ames / Christoph A Diebolder / Klaus Schulten / Zaida Luthey-Schulten / John S Parkinson / Ariane Briegel /
PubMed 要旨	Tsr, the serine chemoreceptor in , transduces signals from a periplasmic ligand-binding site to its cytoplasmic tip, where it controls the activity of the CheA kinase. To function, Tsr forms trimers ...Tsr, the serine chemoreceptor in , transduces signals from a periplasmic ligand-binding site to its cytoplasmic tip, where it controls the activity of the CheA kinase. To function, Tsr forms trimers of homodimers (TODs), which associate with the CheA kinase and CheW coupling protein. Together, these proteins assemble into extended hexagonal arrays. Here, we use cryo-electron tomography and molecular dynamics simulation to study Tsr in the context of a near-native array, characterizing its signaling-related conformational changes at both the individual dimer and the trimer level. In particular, we show that individual Tsr dimers within a trimer exhibit asymmetric flexibilities that are a function of the signaling state, highlighting the effect of their different protein interactions at the receptor tips. We further reveal that the dimer compactness of the Tsr trimer changes between signaling states, transitioning at the glycine hinge from a compact conformation in the kinase-OFF state to an expanded conformation in the kinase-ON state. Hence, our results support a crucial role for the glycine hinge: to allow the receptor flexibility necessary to achieve different signaling states while also maintaining structural constraints imposed by the membrane and extended array architecture. In , membrane-bound chemoreceptors, the histidine kinase CheA, and coupling protein CheW form highly ordered chemosensory arrays. In core signaling complexes, chemoreceptor trimers of dimers undergo conformational changes, induced by ligand binding and sensory adaptation, which regulate kinase activation. Here, we characterize by cryo-electron tomography the kinase-ON and kinase-OFF conformations of the serine receptor in its native array context. We found distinctive structural differences between the members of a receptor trimer, which contact different partners in the signaling unit, and structural differences between the ON and OFF signaling complexes. Our results provide new insights into the signaling mechanism of chemoreceptor arrays and suggest an important functional role for a previously postulated flexible region and glycine hinge in the receptor molecule.
リンク	mBio / PubMed:31266867 / PubMed Central
手法	EM (サブトモグラム平均)
解像度	20.1 - 23.6 Å
構造データ	EMDB-4991: Escherichia coli chemotaxis signaling arrays at low kinase activity with serine receptor mutant Tsr_EEEE 手法: EM (サブトモグラム平均) / 解像度: 23.6 Å EMDB-4992: Escherichia coli chemotaxis signaling arrays at high kinase activity with serine receptor mutant Tsr_QQQQ 手法: EM (サブトモグラム平均) / 解像度: 20.1 Å EMDB-4993: Escherichia coli chemotaxis signaling arrays with wild-type serine receptor Tsr_QEQE 手法: EM (サブトモグラム平均) / 解像度: 22.8 Å
由来	Escherichia coli (大腸菌)