FIG 7.

The alanine at the tip of flavivirus envelope inhibits infectious particle production of yellow fever virus but not West Nile virus. (A) Flavivirus envelope ij loop protein sequence alignment. The orange box indicates the conserved alanine at the tip of the ij loop. (B) Domain II of the WNV (PDB ID 2HG0) and YFV (PDB ID 6IW4) envelope protein. The ij loop and YFV A239 and WNV A247 residues are in red. (C and D) Vero cells were transfected with WT or variant WNV and YFV in vitro-transcribed RNA, and virus-containing supernatant was collected at 48 hpi. Virus titers were quantified by plaque assay. There were 3 independent experiments. (E) C6/36 cells were transfected with WT or variant YFV RNA, and virus-containing supernatant was collected at 72 and 96 hpi. Virus titers were quantified by plaque assay. There were 3 independent experiments.