1887

Abstract

The influenza virus RNA polymerase consists of a heterotrimeric complex of the PB1, PB2 and PA proteins, with the PB2 subunit responsible for recognizing 5′ cap structures on the host cell RNAs used as primers for virus mRNA synthesis. To investigate further the role PB2 plays in mRNA synthesis, a set of polyclonal antisera raised against defined regions of the protein were tested for their ability to inhibit the virion transcriptase. All five sera were of sufficient titre to immunoprecipitate PB2 and four were capable of recognizing polymerase complexes containing PB1 and PA. However, only the serum raised against the carboxy terminus of PB2 (F5) substantially inhibited polymerase activity. This serum drastically reduced synthesis primed by globin mRNA, but only partially inhibited transcription primed by the dinucleotide ApG, or ApG and cap analogue. The preferential inhibition of globin-primed synthesis did not result from interference with cap recognition, as serum F5 did not reduce labelling of PB2 in a photoaffinity cap-binding assay. However, IgG and Fab fragments from F5 were found to inhibit virion endonuclease activity. This suggests that the C terminus of PB2 plays a crucial role in transcription initiation and implicates PB2 in endonuclease activity.

Loading

Article metrics loading...

/content/journal/jgv/10.1099/0022-1317-77-5-1025
1996-05-01
2019-11-22
Loading full text...

Full text loading...

http://instance.metastore.ingenta.com/content/journal/jgv/10.1099/0022-1317-77-5-1025
Loading

Most Cited This Month

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error