Flavivirus particle assembly Flavivirus particle assembly (A) The flavivirus open‐reading frame coding for a single precursor polyprotein. Co‐ and post‐translational proteolytic processing results in the various proteins indicated, with structural and non‐structural proteins in red and blue, respectively. (B–E) Sketches representing the flavivirus particle at different maturation stages (left), with a ribbon representation of the relevant envelope protein complexes on the right. The genomic ribonucleoprotein complex with protein C has not been visualized and is represented here within a central gray circle (in B–D), although its organization is unknown. Protein E is colored according to domains: red, yellow, blue, and green for domains I, II, III, and stem/TM (transmembrane anchor), respectively. The fusion loop is highlighted in orange, and prM/M (including its TM region) is shown in pink. The viral membrane is represented in gray. (B) Left: The immature flavivirus particle as it buds in the ER of the infected cells. Right: A single (prM/E)3 spike is displayed as ribbons (PDB code 4B03). (C) Left: The immature flavivirus particle after exposure to the acidic pH of the trans‐Golgi apparatus, where the trimeric spikes dissociate and the 180 prM/E heterodimers re‐associate into 90 (prM/E)2 dimers. Right: A single (prM/E)2 dimer is shown as ribbons (PDB codes 3C6R and 3JP2). (D) Left: The mature flavivirus particle with 90 (M/E)2 dimers. Right: A single (M/E) 2 dimer is shown in ribbons. (E) Left: Herringbone pattern of E dimers on the surface of mature virus particles, consisting of 30 rafts of three E dimers. One raft is framed in black. Right: Top view of a single E homodimer shown as ribbons. Félix A Rey et al. EMBO Rep. 2017;embr.201745302 © as stated in the article, figure or figure legend