
Determining the structure of proteins and other biomolecules at the atomic level is central to understanding many aspects of biology. X-ray crystallography is the best known technique for structural biology but, as its name suggests, it only works with samples that can be crystallized. Electron cryo-microscopy (cryo-EM) can be used to determine atomic structures of biomolecules that cannot be crystallized, but until now achieving high-resolution cryo-EM structures has been difficult.