Microsecond time-resolved cryo-electron microscopy.

Microsecond time-resolved cryo-electron microscopy has emerged as a novel approach for directly observing protein dynamics. By providing microsecond temporal and near-atomic spatial resolution, it has the potential to elucidate a wide range of dynamics that were previously inaccessible and therefore, to significantly advance our understanding of protein function. This review summarizes the properties of the laser melting and revitrification process that underlies the technique and describes different experimental implementations. Strategies for initiating and probing dynamics are discussed. Finally, the microsecond time-resolved observation of the capsid dynamics of cowpea chlorotic mottle virus, an icosahedral plant virus, is reviewed, which illustrates important features of the technique as well as its potential.