Mutations in the palm region of a plus-strand RNA virus polymerase result in attenuated phenotype.
The three-dimensional structure of RNA-dependent RNA polymerases (RdRps) is highly conserved among RNA viruses. In a previous study, a unique set of mutant strains of Bovine viral diarrhea virus was obtained, encompassing either a genomic deletion of six codons or duplications of between 1 and 45 codons; these mutations affect different parts of the palm region, the most conserved part of RdRps containing the catalytic centre. In the present study, a detailed characterization of the RdRp mutant viruses was performed, demonstrating different degrees of a small-plaque phenotype in cell culture, correlating with significantly reduced viral RNA synthesis and delayed virus replication. Taken together, the results of this study demonstrate a surprising flexibility within the palm region of a plus-strand RNA virus RdRp, resulting in viral attenuation in vitro. This interesting insight into an essential viral protein may have implications for the development of vaccines and attenuated viral vectors.
Gallei
Andreas
A
Institut für Virologie (FB Veterinärmedizin), Justus-Liebig-Universität, Frankfurter Straße 107, D-35392 Giessen, Germany.
Widauer
Simone
S
Institut für Virologie (FB Veterinärmedizin), Justus-Liebig-Universität, Frankfurter Straße 107, D-35392 Giessen, Germany.
Thiel
Heinz-Jürgen
HJ
Institut für Virologie (FB Veterinärmedizin), Justus-Liebig-Universität, Frankfurter Straße 107, D-35392 Giessen, Germany.
Becher
Paul
P
Institut für Virologie (FB Veterinärmedizin), Justus-Liebig-Universität, Frankfurter Straße 107, D-35392 Giessen, Germany.
D000818:Animals; D002417:Cattle; D002460:Cell Line; D001908:Diarrhea Viruses, Bovine Viral / Q000235:genetics* / Q000472:pathogenicity* / Q000502:physiology; D009154:Mutation; D012367:RNA, Viral / Q000096:biosynthesis; D012324:RNA-Dependent RNA Polymerase / Q000737:chemistry / Q000235:genetics*; D011995:Recombination, Genetic; D017384:Sequence Deletion; D013223:Statistics as Topic; D010948:Viral Plaque Assay; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics*; D014774:Virulence / Q000235:genetics; D014779:Virus Replication / Q000235:genetics
D012367:RNA, Viral; D014764:Viral Proteins; D012324:RNA-Dependent RNA Polymerase