Objective To study an amino acid mutation(P639S/G)in the VP1 capsid protein of enterovirus 71(EV71)strains with different levels of virulence.A mutant rescue virus was generated to determine if the amino acid mutation affects viral production or virulence in cells. Methods A reverse genetics approach was used to construct a mutant virus based on the full-length cDNA of infectious EV71.A rescue virus was obtained by transfecting that cDNA into cells.The rescue virus was stably passaged and characterized usin...