DNA POLYMERASE FROM RAT LIVER CHROMOSOMAL PROTEINS .I. PARTIAL PURIFICATION AND GENERAL CHARACTERISTICS

A replicative DNA polymerase has been partially purified from the nonhistone chromosomal proteins of rat liver. The enzyme exhibited an absolute requirement for DNA and divalent metal ions, especially Mg2+. The complete supplement of all four deoxyriboside-5′-triphosphates was necessary for optimal enzymic activity. Experiments employing the synthetic polydeoxynucleotides, poly dA and poly dA:dT, demonstrated the replicative nature of the enzyme as well as its preference for a native DNA or double-stranded template. The chromosomal polymerase manifested variations in enzymic activity when templated with DNA's from different sources and showed the greatest activity in the presence of homologous rat liver nuclear DNA. The method of enzyme isolation and the characteristics of the enzymic reaction are described. © 1969.