In cells of our body, motor proteins in cells convert chemical energy into the mechanical energy of movement, thereby activating cell movement. Dynein plays a role in the transportation of materials in cells and the motility of cilia and flagella. Because of its molecular complexity and its big size, of the major molecular motors, only the structure of dynein is not well-known and its motion mechanism has been mystery-shrouded.

Findings

The figure 1 below shows the atomic-resolution structure of the dynein motor in the cellular slime mold that the group has clarified. It was concluded that dynein has a structure in which long two legs projecting from the ring having the capability to hydrolyze ATP, and that dynein moves over microtubules by letting these two legs change in structure.
The lever-arm structure for force generation over the ring was also observed. Thus, the group clarified the mechanism to convert chemical energy obtained by hydrolyzing ATP to mechanical energy on the atomic level.
This group showed that these structural features are totally different from small molecular motors such as myosin and kinesin and that dynein is a molecular motor moving along microtubles through a different motion mechanism.
This protein structure was clarified using BL-44XU Beamline at SPring8, the largest synchrotron radiation facility at Osaka University, breaking the record of the longest polypeptide chain that had been defined.
This prodigious feat was

Figure 1: Atomic structure of Dynein, a motor protein