English: Conformational differences between the HvV190S virion and VLPC+ capsid structures. Differences are highlighted by means of an animation produced with the Morph Map tool and default values in Chimera [63]. 3D density maps of the virion and VLPC+ cryo-reconstructions, each band-limited to 9.0-Å resolution and with the front-half removed (also genome density in the virion) to reveal external as well as internal features in the capsid shell, served as the initial and final data sets. The capsid undergoes subtle, coordinated conformational changes akin to “breathing” in response to loss of genome, with regions near the two- and threefold axes expanding and near the fivefold axes contracting during the transition from virion to VLPC+. These conformational changes suggest that attractive and repulsive electrostatic forces govern interactions between the genome and the inner surface of the capsid. Close inspection of the animation shows that some regions of the capsid undergo little if any conformational change between the two structures.