The main file shows a superstructure the paper proposes for HSV's entry-essential glycoproteins that would stabilize a compact form of the gB fusogen: The compact form of the gB trimer (blue/mauve/cyan) is surrounded by a ring of three gHgL heterodimers (pink/grey/magenta) that are in turn held in place by three gD glycoproteins (green). Also shown are Nectin (orange) and HVEM (purple) in their binding configurations to gD, illustrating the lack of steric hindrance with the rest of the superstructure. These are held to be transition states, because either Nectin or HVEM can displace a region on gD that then binds to gHgL, which would cause each one in turn to adopt the open configuration shown in the other file. Once all three gHgL are in the open configuration the hairpin loops of gB would be free to rotate, allowing gB to spring upwards into the cell membrane. Active cellular forces pulling inwards on the gD receptors then continue to pull the entire complex via gD, causing fusion of the cell membrane with the viral envelope and releasing the tegument and capsid into the cell. This mechanism is consistent with the finding [JACS 2013, 135, 11175 dx.doi.org/10.1021/ja4038406 ] that a single gD unbound by antibody is sufficient for HSV entry to some cell types, because each superstructure would require all three gDs to be activated by binding one of their receptors, Nectin-1 or Nectin-2, Herpes Virus Entry Mediator (HVEM), or 3-O-Sulfated Heparan Sulfate (3OSHS) on Syndecan-1 or Syndecan-2. For full references please see ACS Infectious Diseases, 1.9 (2015): 403-415 http://pubs.acs.org/doi/abs/10.1021/acsinfecdis.5b00059 Open Access: https://www.repository.cam.ac.uk/handle/1810/257391