Some of the expected conformational changes induced by low-pH in the gpGVHSV pre-fusion homotrimer include the following similarities to gpGVSV: i) TrD α-helix (Figure , red) extension by refolded R4-linkers (Figure green), ii) R5-linker α-helix extension/reorientations (Figure , yellow), and iii) R1-linker refoldings to lateral α-helices (Figure , blue). Among all the above mentioned theoretical possibilities to interfere, the highly conserved pre-fusion homotrimer R4-TrD interface of gpGVHSV was chosen as the working hypothesis to computationally interfere the fusion transitions at one of its earliest steps.