FIG 3.

NS3 and NS4A substitutions enhance replication of GT6a replicons. In vitro-transcribed GT6a-RlucNeo replicon RNAs, from either the parental replicon or replicons engineered to encode the indicated NS3 substitution (E30V or K272R) or NS4A substitution (K34R), were transfected into Lunet cells and subjected to selection by G418 (0.5 mg/ml). G418-resistant colonies harboring GT6a replicons emerged after approximately 3 weeks and were visualized by staining with crystal violet. All replicons encode the NS5A amino acid substitution S232I.