Differential role of the influenza A virus polymerase PA subunit for vRNA and cRNA promoter binding.
The RNA polymerase of influenza A virus is a heterotrimeric complex of PB1, PB2 and PA subunits that is required for transcription and replication of the viral genome. Here, we demonstrate a differential requirement of the PA subunit for binding to the vRNA and cRNA promoters--specifically, PA is more important for binding to the cRNA than the vRNA promoter. Furthermore, five point mutations were identified in the L163-I178 region of PA, which resulted in an inhibition of polymerase activity when provided with a cRNA compared to vRNA promoter. Cross-linking studies suggested that this inhibition was due to a reduction in promoter binding of the mutant polymerases to the cRNA promoter. We conclude that the L163-I178 region of PA is directly or indirectly involved in cRNA promoter binding and suggest a novel function for PA in modulating promoter binding.
Maier
Helena J
HJ
Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK.
Kashiwagi
Takahito
T
Hara
Koyu
K
Brownlee
George G
GG
D002460:Cell Line; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D009980:Influenza A virus / Q000201:enzymology* / Q000378:metabolism; D017354:Point Mutation; D011401:Promoter Regions, Genetic / Q000502:physiology*; D018075:RNA, Complementary / Q000378:metabolism*; D012367:RNA, Viral / Q000378:metabolism*; D012324:RNA-Dependent RNA Polymerase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
C061290:PA protein, influenza viruses; D018075:RNA, Complementary; D012367:RNA, Viral; D014764:Viral Proteins; D012324:RNA-Dependent RNA Polymerase; D012321:DNA-Directed RNA Polymerases