Complementary Use of Electron Cryomicroscopy and X-Ray Crystallography: Structural Studies of Actin and Actomyosin Filaments
Visualization of macromolecular structures is essential for understanding the mechanisms of biological functions because they are all determined by the structure and dynamics of macromolecular complexes. Electron cryomicroscopy (cryoEM) and image analysis has become a powerful tool for structural studies because of recent technical developments in microscope optics, cryostage control, image detection and the methods of sample preparation. In particular, the recent development of CMOS-based direct electron detectors with high sensitivity, high resolution and high frame rate has revolutionized the field of structural biology by making near-atomic resolution structural analysis possible from small amounts of solution samples. However, for some biological systems, it is still difficult to reach high resolution due to somewhat flexible nature of the structure, and a complementary use of cryoEM with X-ray crystallography is essential and useful to gain mechanistic understanding of the biological functions and mechanisms. We will describe our strategy for the structural analyses of actin filament and actomyosin rigor complex and the biological insights we gained from these structures.
KeywordsHybrid method for structural analysis Electron cryomicroscopy Image analysis 3D reconstruction X-ray crystallography F-actin assembly Treadmill Actomyosin motor Skeletal muscle contraction Biased Brownian motion
This work was supported by JSPS KAKENHI Grant number 25711010 to T.F and 25000013 to K.N.
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