ABSTRACT
In eukaryotes, RNA is synthesized by three RNA polymerases: RNA Pol I is a nucleolar enzyme that transcribes rRNAs, RNA Pol II is located in the nucleoplasm and transcribes mRNAs, snoRNAs and most snRNAs, RNA Pol III is also nucleoplasmic and transcribes tRNA and 5S rRNA, as well as U6 snRNA and the 7S RNA of the signal recognition particle (SRP).
