DNA Polymerases of Myeloma: Template and Primer Specificities of Two Enzymes

INTEREST in the viral RNA-dependent DNA polymerases 1,2 has led to an examination of mammalian DNA polymerases and to the characterization in certain systems of DNA polymerases which can transcribe ribopolymer chains of appropriate ribopolymer-oligodeoxyribopolymer hybrids 3,4 . The nature of these enzymes and their function in cells are unclear. We have reported the separation, by chromatography on DEAE-cellulose, of the DNA polymerases of the murine myeloma tumour into two separate fractions which we have designated as fractions D-I and D-II (ref. 5). Each of these fractions contains an activity capable of utilizing activated DNA and of transcribing the ribopolymer strand of poly rA oligo dT. We describe here the separation of two DNA polymerase enzymes in fraction D-I.