RNA polymerase of influenza virus. Dinucleotide-primed initiation of transcription at specific positions on viral RNA.

A Honda,K Mizumoto,A Ishihama

doi:10.1016/s0021-9258(17)38482-x

Abstract

The priming activities of dinucleotides of all possible base sequences as to the transcription initiation by influenza virus-associated RNA polymerase were investigated. Dinucleotide ApG, complementary to positions 1-2 from the 3' termini of viral RNA segments, was the most active primer and directed the formation of ApGpC; dinucleotide GpC, complementary to positions 2-3, was also an active primer and directed the formation of either GpCpG or GpCpA; but both dinucleotides CpG and CpU, complementary to positions 3-4, were virtually inactive. These results indicate that the transcription is initiated within the first four nucleotides at the 3' termini of viral RNA. Among other dinucleotides, only those hybridizable to viral sequences at their 3'-proximal bases were partially active, implying the essential role of base pairing immediately next to the first phosphodiester bond.

Highlights

From the $Department of Molecular Genetics, National Institute of Genetics, Mishim, Shizuoka 411 and the §Departmentof Biochemistry, Institute of Medical Science, University of Tokyo, Minato-ky Tokyo108,Japan
Was the mostactive primer and directed the formation For detailed understanding of the molecular mechanism of of ApGpC; dinucleotide GpC, complementary to posi- primer-dependent initiation of transcription by the influenza tions 2-3, was an active primer and directed the formation of either GpCpG or GpCpA; but both dinucleotides CpG and CpU, complementary to positions 4, were virtually inactive. These results indicate that the transcriptionis initiated within the first four nucleotides at the 3’ termini of viral RNA
The RNA-dependent RNA polymerase (nucleoside-triphosphate:RNA nucleotidyltransferase (DNA-directed) (EC 2.7.7.6)) associated with the influenza virus plays an essential role in transcription and replication of the viral genome

Summary

ON VIRALRNA*

Was the mostactive primer and directed the formation For detailed understanding of the molecular mechanism of of ApGpC; dinucleotide GpC, complementary to posi- primer-dependent initiation of transcription by the influenza tions 2-3, was an active primer and directed the formation of either GpCpG or GpCpA; but both dinucleotides CpG and CpU, complementary to positions 4, were virtually inactive. These results indicate that the transcriptionis initiated within the first four nucleotides at the 3’ termini of viral RNA.

RESULTS

Transcription Initiationby Influenza VirusRNA Polymerase

DISCUSSION

GS cc us GU

InitiLaaDtbiienolunecdleIontiitdieation psousbistiroante primer

RNA Polymerase