Identification of subunits of RNA polymerase II from Ehrlich ascites tumor cells

A procedure was developed for large scale purification of RNA polymerase II from Ehrlich ascites tumor cells. About 2 mg of purified enzyme was obtained from 800 g of wet cells. Ten subunits were identified which behaved corresponding to the enzyme activity both on DEAE-Sephadex chromatography and on glycerol density gradient centrifugation. Analysis of tryptic peptides of each subunit showed that these subunits were independent proteins and not structurally related to each other.