Three-dimensional structures of the flagellar dynein-microtubule complex by cryoelectron microscopy

The outer dynein arms (ODAs) of the flagellar axoneme generate forces needed for flagellar beating. Elucidation of the mechanisms underlying the chemomechanical energy conversion by the dynein arms and their orchestrated movement in cilia/flagella is of great importance, but the nucleotide-dependent three-dimensional (3D) movement of dynein has not yet been observed. In this study, Ι establish a new method for reconstructing the 3D structure of the in vitro reconstituted ODA–microtubule complex and visualize nucleotide-dependent conformational changes using cryoelectron microscopy and image analysis. As the complex went from the rigor state to the relaxed state, the head domain of the ß heavy chain shifted by 3.7 nm toward the B tubule and inclined 44° inwards. These observations suggest that there is a mechanism that converts head movement into the axonemal sliding motion.報告番号: 甲24771 ; 学位授与年月日: 2009-03-23 ; 学位の種別: 課程博士 ; 学位の種類: 博士(医学) ; 学位記番号: 博医第3191号 ; 研究科・専攻: 医学系研究科分子細胞生物学専