Yellow fever 17D virus: pseudo-revertant suppression of defective virus penetration and spread by mutations in domains II and III of the E protein.
A yellow fever (YFV) 17D virus variant, which causes persistent infection of mouse neuroblastoma cells associated with defective cell penetration and small plaque size, yielded plaque-revertant viruses from cells transfected with viral transcripts encoding the adaptive mutation (Gly360 in the E protein). Reconstruction of a plaque-purified revertant which contained Gly360 and additional substitutions (Asn for Lys303 and Val for Ala261) yielded a virus whose infectious center size, growth efficiency, and cell penetration rate similar to the parental YF5.2iv virus, whereas viruses with Asn303 or Val261 alone with Gly360 yielded either a small-plaque virus or a parental revertant. These data indicate that the YFV E protein is subject to suppression of mutations in domain III that are deleterious for viral entry and spread by a second-site mutation in domain II. Position 261 lies within the hydrophobic ligand-binding pocket at the domain I-II interface, a site believed to be involved in the hinge-like conformational change of domain II during activation of membrane fusion-activity. Results of this study provide genetic data consistent with findings on flavivirus structure and implicate domain III in functions beyond simply cell surface attachment.
Vlaycheva
Leonssia
L
Department of Molecular Microbiology and Immunology, Saint Louis University Health Sciences Center, St. Louis, MO 63104, USA.
Nickells
Michael
M
Droll
Deborah A
DA
Chambers
Thomas J
TJ
D000595:Amino Acid Sequence; D000818:Animals; D002522:Chlorocebus aethiops; D003673:Defective Viruses / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D013489:Suppression, Genetic; D014709:Vero Cells; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010948:Viral Plaque Assay; D015005:Yellow fever virus / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology
D014759:Viral Envelope Proteins; C078400:yellow fever virus envelope protein E