ジャーナル: EMBO J / 年: 2006 タイトル: High-resolution cryo-EM maps show the nucleotide binding pocket of KIF1A in open and closed conformations. 著者: Masahide Kikkawa / Nobutaka Hirokawa / 要旨: Kinesin is an ATP-driven microtubule (MT)-based motor fundamental to organelle transport. Although a number of kinesin crystal structures have been solved, the structural evidence for coupling ...Kinesin is an ATP-driven microtubule (MT)-based motor fundamental to organelle transport. Although a number of kinesin crystal structures have been solved, the structural evidence for coupling between the bound nucleotide and the conformation of kinesin is elusive. In addition, the structural basis of the MT-induced ATPase activity of kinesin is not clear because of the absence of the MT in the structure. Here, we report cryo-electron microscopy structures of the monomeric kinesin KIF1A-MT complex in two nucleotide states at about 10 A resolution, sufficient to reveal the secondary structure. These high-resolution maps visualized clear structural changes that suggest a mechanical pathway from the nucleotide to the neck linker via the motor core rotation. In addition, new nucleotide binding pocket conformations are observed that are different from X-ray crystallographic structures; it is closed in the 5'-adenylyl-imidodiphosphate state, but open in the ADP state. These results suggest a structural model of biased diffusion movement of monomeric kinesin motor.
名称: KIF1A head decorated-microtubule complex / タイプ: COMPLEX 詳細: SAMPLE DETAILS: TUBULIN WAS POLYMERIZED IN PEM BUFFER (PIPES 100 MM, PH 6.8, EGTA 1 MM, MGCL2, GTP 1MM, PACLITAXEL 10 MICRO M, 5% DMSO ) FOR 2 HRS AT 37C. A DROP OF THE POLYMERIZED ...詳細: SAMPLE DETAILS: TUBULIN WAS POLYMERIZED IN PEM BUFFER (PIPES 100 MM, PH 6.8, EGTA 1 MM, MGCL2, GTP 1MM, PACLITAXEL 10 MICRO M, 5% DMSO ) FOR 2 HRS AT 37C. A DROP OF THE POLYMERIZED MICROTUBULE WAS PLACED ON THE HOLEY CARBON FILM ON THE EM-GRID AND LEFT FOR 10 S IN THE HUMID CHAMBER. THE MICROTUBULE SOLUTION WAS THEN ABSORBED BY FILTER PAPER, AND A DROP OF THE C351 SOLUTION (0.2 MG/ML) IN THE ASSAY BUFFER (IMIDAZOLE 50 MM, MG-ACETATE 5 MM, EGTA 1 MM, K-ACETATE 50 MM, DTT 10 MM, PACLITAXEL 10 MICRO M) WAS PUT ON THE GRID. IMMEDIATELY AFTER THE ABSORPTION OF THE DROP, THE GRID WAS PLUNGED INTO LIQUID ETHANE (-185C).
緩衝液
名称: IMIDAZOLE / pH: 7.4 / 詳細: IMIDAZOLE
試料
濃度: 0.2 mg/ml / 包埋: NO / シャドウイング: NO / 染色: NO / 凍結: YES