Dynamic 3D visualization of active protein′s motion using diffracted X-ray tracking

Diffracted X-ray tracking (DXT) is one of the single-molecule techniques for investigating intra-molecule dynamics of functional proteins at the single-molecule level with nanocrystal and synchrotron X-ray. In DXT, a nanocrystal is immobilized on a target protein, used as a motion probe and the trajectory of its diffraction spot is analyzed as the internal motion of the protein. It can detect atomic-scale dynamic motion of the protein with several tens of microseconds time resolution. Therefore, DXT is expected to be a powerful tool to investigate protein inter-molecule dynamics, especially for cooperative motion analysis in multimeric proteins. In this article, we review the characteristic features and recent progress of DXT.