ジャーナル: Proc Natl Acad Sci U S A / 年: 2014 タイトル: Structure, domain organization, and different conformational states of stem cell factor-induced intact KIT dimers. 著者: Yarden Opatowsky / Irit Lax / Francisco Tomé / Franziska Bleichert / Vinzenz M Unger / Joseph Schlessinger / 要旨: Using electron microscopy and fitting of crystal structures, we present the 3D reconstruction of ligand-induced dimers of intact receptor tyrosine kinase, KIT. We observe that KIT protomers form ...Using electron microscopy and fitting of crystal structures, we present the 3D reconstruction of ligand-induced dimers of intact receptor tyrosine kinase, KIT. We observe that KIT protomers form close contacts throughout the entire structure of ligand-bound receptor dimers, and that the dimeric receptors adopt multiple, defined conformational states. Interestingly, the homotypic interactions in the membrane proximal Ig-like domain of the extracellular region differ from those observed in the crystal structure of the unconstrained extracellular regions. We observe two prevalent conformations in which the tyrosine kinase domains interact asymmetrically. The asymmetric arrangement of the cytoplasmic regions may represent snapshots of molecular interactions occurring during trans autophosphorylation. Moreover, the asymmetric arrangements may facilitate specific intermolecular interactions necessary for trans phosphorylation of different KIT autophosphorylation sites that are required for stimulation of kinase activity and recruitment of signaling proteins by activated KIT.
全体 : Intact human KIT dimer in complex with stem cell factor (SCF)dimer
全体
名称: Intact human KIT dimer in complex with stem cell factor (SCF)dimer
要素
試料: Intact human KIT dimer in complex with stem cell factor (SCF)dimer
タンパク質・ペプチド: stem cell growth factor
タンパク質・ペプチド: KIT
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超分子 #1000: Intact human KIT dimer in complex with stem cell factor (SCF)dimer
超分子
名称: Intact human KIT dimer in complex with stem cell factor (SCF)dimer タイプ: sample / ID: 1000 / 集合状態: one dimer of SCF binds to KIT dimer / Number unique components: 2
照射モード: FLOOD BEAM / 撮影モード: BRIGHT FIELD / 倍率(公称値): 30000
試料ステージ
試料ホルダーモデル: OTHER / Tilt angle max: 55
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画像解析
詳細
Particles of tilt pairs (at 0 and 55 degrees)were manually selected using WEB. Initial reference-free alignment and classification of the untilted views was performed using IMAGIC-5. A representative class average was used for reference-based alignment, followed by cycles of multireference alignment and classification. Three out of 8 classes were used in random conical tilt reconstruction using SPIDER.
最終 再構成
想定した対称性 - 点群: C1 (非対称) / 解像度のタイプ: BY AUTHOR / 解像度: 28.8 Å / 解像度の算出法: OTHER / ソフトウェア - 名称: SPIDER / 使用した粒子像数: 1900