Since Perutz, Kendrew and colleagues unveiled the structure of hemoglobin and
myoglobin based on X-ray diffraction analysis in the 1950s, X-ray
crystallography has become the primary methodology used to determine the 3D
structure of macromolecules. However, biological specimens such as cells,
organelles, viruses and many important macromolecules are difficult or
impossible to crystallize, and hence their structures are not accessible by
crystallography. Here we report, for the first time, the recording and
reconstruction of X-ray diffraction patterns from single, unstained viruses.
The structure of the viral capsid inside a virion was visualized. This work
opens the door for quantitative X-ray imaging of a broad range of specimens
from protein machineries, viruses and organelles to whole cells. Moreover, our
experiment is directly transferable to the use of X-ray free electron lasers,
and represents a major experimental milestone towards the X-ray imaging of
single macromolecules.Comment: 16 pages, 5 figure