Single-particle cryo-electron microscopy

Within the past few years, the technique of cryo-electron microscopy (cryo-EM) combined with single-particle analysis has become a competitor of X-ray crystallography in the study of macromolecules, now routinely reaching a near-atomic resolution for molecules of sufficient size. Its advantages over X-ray crystallography are that no crystals are required, that large and flexible molecules can be studied, and that the molecules can be captured in multiple functionally relevant conformations. Important molecular machines involved in the fundamental processes of transcription, mRNA editing and translation are examples for successful applications. The present work gives an overview of single-particle cryo-EM as currently practiced.