A Ca2+-dependent DNA primase-like activity from HeLa cells

Novel DNA primase-like activity was partially purified from human Hela cells, and the activity was clearly separated from DNA polymerase alpha by phosphocellulose column chromatography. The enzyme did not show significant activity in the absence of Ca2+, and was dramatically activated by the addition of Ca2+; so it was designated as C-primase. The C-primase showed a molecular weight of 20,000 estimated by gel filtration and a sedimentation coefficient of 3.5 S by glycerol gradient centrifugation. These results, together with the other properties of the C-primase, suggest that this primase like-enzyme is distinct from the authentic eukaryotic primase in the DNA polymerase alpha/DNA primase complex.