Photochemical cross-linking of influenza A polymerase to its virion RNA promoter defines a polymerase binding site at residues 9 to 12 of the promoter.
A previous study of the 12 nucleotide-long influenza A virion RNA promoter has shown that three nucleotides, residues 9 to 11, were crucial for transcription in vitro, although other nucleotides play a significant but less important role. A model for polymerase-promoter recognition was proposed, according to which there were two sites: a binding site at residues 9 to 11 and a regulatory site at or near the site of initiation at residue 1. By studying the effect of point mutations in the promoter on the binding efficiency of the polymerase using a photochemical cross-linking assay, we now show that residues 9 to 12 are crucial for binding. In addition residues 4 to 8, though not as important, are involved in binding, possibly by stabilizing the polymerase-promoter complex. Both PB1 and PB2 apparently play an important role during virion RNA promoter recognition and binding.
Fodor
E
E
Chemical Pathology Unit, Sir William Dunn School of Pathology, University of Oxford, U.K.
Seong
B L
BL
Brownlee
G G
GG
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D017124:Conserved Sequence; D003432:Cross-Linking Reagents; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism*; D009980:Influenza A virus / Q000201:enzymology* / Q000235:genetics*; D007700:Kinetics; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D016297:Mutagenesis, Site-Directed; D010777:Photochemistry; D017354:Point Mutation; D011401:Promoter Regions, Genetic; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism*; D011817:Rabbits / Q000276:immunology; D013698:Templates, Genetic; D014771:Virion / Q000201:enzymology / Q000235:genetics*
D003432:Cross-Linking Reagents; D012367:RNA, Viral; D012321:DNA-Directed RNA Polymerases