| Type | Present in | Transcribes |
|---|---|---|
| RNA polymerase I | All eukaryotes | Large rRNAs |
| RNA polymerase II | All eukaryotes | Pre-mRNA, some snRNAs, snorNas, some miRNAs |
| RNA polymerase III | All eukaryotes | tRNAs, small rRNAs, some snRNAs, some miRNAs |
| RNA polymerase IV | Plants | Some siRNAs |
| RNA polymerase V | plants | RNA molecules taking part in heterochromatin formation |