A DNA polymerase alpha catalytic subunit is purified independently from the tissues at meiotic prometaphase I of a basidiomycete, Coprinus cinereus.

A 135kDa DNA polymerase alpha lacking primase activity has been purified to near homogeneity from Coprinus meiotic tissues. The activity of the DNA polymerase was sensitive to aphidicolin and N-ethylmaleimide, but was insensitive to dideoxythymidine triphosphate. DNA synthesis was proceeded with a low processivity. Neither activity nor processivity were affected by PCNA in the presence or absence of KCI. Monovalent cation inhibited its activity. These biochemical properties are almost identical to those of Coprinus DNA polymerase alpha -primase complex. However, the 135kDa DNA polymerase did not use activated DNA as a template-primer, inconsistent with Coprinus DNA polymerase alpha-primase complex. The 135kDa DNA polymerase was purified from the tissues at meiotic pro-metaphase I, suggesting that the alpha- DNA polymerase-primase complex dissociates as the meiotic cell cycle progresses and only the catalytic subunit remains at this stage.