(D) The ab initio shape envelopes of the DB12s of DENV2 (left), ZIKV (middle) and WNV (right) in two views. The atomic models from de novo structure modeling by Rosetta were superimposed onto the respective envelopes. The back-calculated scattering profiles of the de novo atomic models are fitted to the respective experimental scattering profiles in (A). (E) The ab initio shape envelopes of the PK3 mutants of ZIKV DB12s, the ZIKV-DB12-PK3∆ (left) and WNV-DB12-PK3∆ (right) in two views, suggesting open conformations upon PK3 mutations. 