Purification and partial characterization of a DNA polymerase alpha species from calf thymus

We have purified a DNA polymerase alpha species from calf thymus to near homogeneity. The enzyme sediments at 5.7 S and contains two polypeptides of 123000 and 134000 daltons in about equimolar ratio. The enzyme is inhibited by aphidicolin and N-ethylmaleimide, and retains its activity in buffers containing moderate salt conditions. Activated DNA is a better substrate than poly-(dA) . (dT) 10.