Purification of a 9S DNA polymerase .alpha. species from calf thymus

Abstract
A DNA polymerase .alpha. species from calf thymus was purified 12,000-fold to near homogeneity. The enzyme sediments under high salt conditions in the preparative ultracentrifuge as a homogeneous band at 9 S. The specific activity is 50,000-70,000 U/mg of protein. Polypeptides of 148,000, 59,000, 55,000 and 48,000 daltons are detectable. The MW as estimated from gradient gel electrophoresis is .apprx. 500,000. The 9S DNA polymerase is free from terminal nucleotidyl transferase activity and does not exhibit endonuclease or exonuclease activity. It is inhibited by low concentrations of salt, aphidicolin and N-ethylmaleimide.