RNAs nonspecifically inhibit RNA polymerase II by preventing binding to the DNA template

Preincubation of Pol II with RNAs inhibits transcript formation. (A) Inhibition of Pol II transcription by pre-tRNA^Tyr. Indicated amounts of pre-tRNA^Tyr were incubated with a constant amount of Pol II (30 nM) for 15 min at 30°C. The Pol II-RNA complex was then incubated with plasmid DNA template and then added to NTPs. Reactions proceeded for 25 min and then were boiled in formamide and loaded onto a 10% denaturing gel. (B) The reaction in A was repeated in triplicate for four different RNAs. The total radioactive signal per lane was quantitated and plotted.