Polyoma Virion and Capsid Crystal Structures

Abstract
X-ray diffraction shows that complete virus particles and empty capsids crystallize isomorphously. The surface morphology of the protein coat, as revealed by electron microscopy, is the dominant structural feature determining the intensity of x-ray reflections to a resolution of approximately 30 angstroms. The structure and variability of the viral chromatin core can now be analyzed by comparison of electron density maps.