small RNA methods
Recorded terms: primer extension
Uncoupling the two steps of influenza A virus genome replication with viral promoter mutations shows that ANP32A is required for synthesis of both the complementary RNA intermediate and progeny genomic RNA, and that it acts on the actively replicating polymerase rather than the encapsidating one.
Influenza A virus small viral RNAs are shown to be synthesized from the complementary RNA intermediate, to load into the RNA binding cleft of the polymerase PA subunit, and to act there as segment-specific allosteric enhancers of full-length genome synthesis.
Influenza A virus produces a family of 22 to 27 nucleotide small viral RNAs corresponding to the 5 prime end of each genomic segment, which accumulate as the polymerase shifts toward genome synthesis and whose inhibition selectively depletes genomic RNA without comparably affecting messenger or complementary RNA.