Eukaryotes express at least three nuclear DNA-dependent RNA polymerases (Pols)
responsible for synthesizing all RNA required by the cell. Despite sharing structural
homology, they have functionally diverged to suit their distinct cellular roles. Although the
Pols have been studied extensively, direct comparison of their enzymatic properties is
difficult because studies are often conducted under disparate experimental conditions and
techniques. Here, we directly compare and reveal functional differences between …