Partial purification of a stimulatory factor of RNA polymerase B in nonhistone proteins; correlation with nuclear protein kinase.

A stimulatory factor of DNA-dependent RNA polymerase B (nucleosidetriphosphate: RNA nucleotidyltransferase, EC 2.7.7.6) in nonhistone proteins was partially purified from rat liver nuclei on a column of daunomycin-CH Sepharose 4B and of phosphocellulose. In the process of purification, the stimulatory factor was separated from the main fraction of nuclear protein kinase (ATP: protein phosphotransferase, EC 2.7.1.37). This factor enhanced specifically the activity of RNA polymerase B on rat liver DNA as template and did not affect RNA polymerase A and Escherichia coli RNA polymerase at all. The polynucleotide elongation rate was increased by the addition of this factor.