X-ray imaging of a single virus in 3-D

Since the determination of the molecular structure of myoglobin in 1957, X-ray crystallography has been the defining tool of structural biology, allowing researchers to determine the structure (and hence the function) of tens of thousands of proteins, nucleic acids, and other biological molecules. But the method can only work for molecules that form large, high quality crystals. An international team of scientists has now used the intense beam of Stanford’s Linac Coherent Light Source (LCLS) [the world’s first hard x-ray free-electron laser (XFEL) and one of only two currently operating in the world] to demonstrate that it is possible to reconstruct the 3D structure of a virus particle without the need of a crystal, by combining many diffraction patterns collected from a sequence of randomly oriented single viruses. Solving the structure of single molecules would have profound implications for biology, as many important molecules cannot be crystallized. This is the case for...