Biophysical characterization and vector-specific antagonist activity of domain III of the tick-borne flavivirus envelope protein

The molecular determinants responsible for flavivirus host cell binding and tissue tropism are largely unknown, although domain III of the envelope pr otein has been implicated in these functions. We examined the solution prop erties and antagonist activity of Langat virus domain III. Our results sugg est that domain III adopts a stably folded structure that can mediate bindi ng of tick-borne flaviviruses but not mosquito-borne flaviviruses to their target cells. Three clusters of phylogenetically conserved residues are ide ntified that may be responsible for the vector-specific antagonist activity of domain III.