Solubilized DNA‐dependent RNA polymerase from human placenta: A Mn2+‐dependent enzyme

Abstract
The 100-fold purified RNA polymerase activity from human placenta is completely dependent upon added DNA. The enzyme is most active at 3 mM Mn2+ in the presence of 100 mM (NH4)2SO4. Denatured DNA is a better template than native DNA. α-Amanitin completely inhibits the incorporation of 3H-UMP, while rifampicin has no influence upon the enzymatic activity.