Utilization of mammalian 70S RNA by a purified reverse transcriptase from human myelocytic leukemic cells

Abstract

A DNA polymerase activity present in the 60,000 × g pellet of human acute myelocytic leukemic blood cells catalyzes an endogenous RNA-dependent (RNase sensitive) DNA synthesis. After purification, this enzyme transcribes heteropolymeric regions of 70S RNA from various RNA tumor viruses but prefers mammalian over avian viral RNA. DNA transcribed from the viral RNA is, like that from RNA tumor virus reverse transcriptase, hydrogen bonded and covalently attached to the RNA template-primer. The DNA transcript, after alkaline hydrolysis, hybridizes specifically to the template-primer RNA. This activity is not decreased in the presence of DNA polymerases from normal cells, suggesting that the inability of the latter polymerases to catalyze transcription of viral RNA is not due to the presence of inhibitor(s). This DNA polymerase is easily distinguished from a terminal addition deoxynucleotidyl transferase and has previously been shown to be immunologically closely related to primate type-C virus reverse transcriptase.