RNA polymerase

• viral RNA-dependent RNA polymerase : discovered in 1960's

• four common motifs A-D :

• • Motif C contains Gly-Asp-Asp, changing first Asp in 3Dpol produces inactive polymerase

• 3Dpol

• • • template and primer dependent
    • no proofreading : error frequency (103 – 104)
    • highly efficient: 1 RNA -> 50 000 copies in 8 hours
    • elongation in 5' – 3' direction