ジャーナル: Structure / 年: 2006 タイトル: An expanded conformation of single-ring GroEL-GroES complex encapsulates an 86 kDa substrate. 著者: Dong-Hua Chen / Jiu-Li Song / David T Chuang / Wah Chiu / Steven J Ludtke / 要旨: Electron cryomicroscopy reveals an unprecedented conformation of the single-ring mutant of GroEL (SR398) bound to GroES in the presence of Mg-ATP. This conformation exhibits a considerable expansion ...Electron cryomicroscopy reveals an unprecedented conformation of the single-ring mutant of GroEL (SR398) bound to GroES in the presence of Mg-ATP. This conformation exhibits a considerable expansion of the folding cavity, with approximately 80% more volume than the X-ray structure of the equivalent cis cavity in the GroEL-GroES-(ADP)(7) complex. This expanded conformation can encapsulate an 86 kDa heterodimeric (alphabeta) assembly intermediate of mitochondrial branched-chain alpha-ketoacid dehydrogenase, the largest substrate ever observed to be cis encapsulated. The SR398-GroES-Mg-ATP complex is found to exist as a mixture of standard and expanded conformations, regardless of the absence or presence of the substrate. However, the presence of even a small substrate causes a pronounced bias toward the expanded conformation. Encapsulation of the large assembly intermediate is supported by a series of electron cryomicroscopy studies as well as the protection of both alpha and beta subunits of the substrate from tryptic digestion.
名称: ATPase-deficient Single-ring GroEL Mutant SR398 / タイプ: sample / ID: 1000 詳細: The two components for the sample were mixed with Mg-ATP at Room Temperature 集合状態: One heptamer of GroES binds to one heptamer of SR398 Number unique components: 2
分子量
実験値: 470 KDa / 理論値: 470 KDa
-
分子 #1: SR398
分子
名称: SR398 / タイプ: protein_or_peptide / ID: 1 / 詳細: This is the GroEL protein with D398A mutation / コピー数: 1 / 集合状態: Heptamer / 組換発現: Yes
凍結剤: ETHANE / チャンバー内湿度: 100 % / チャンバー内温度: 95 K / 装置: OTHER / 詳細: Vitrification instrument: FEI Vitrobot 手法: Blot twice and 1.5 seconds for each blot before plunging.
-
電子顕微鏡法
顕微鏡
JEOL 2010F
温度
平均: 95 K
アライメント法
Legacy - 非点収差: objective lens astigmatism was corrected at 200,000 times magnification