Isolation and Characterization of a Protein that Stimulates DNA Synthesis from Avian Myeloblastosis Virus

A protein has been isolated from avian myeloblastosis virus that stimulates the rate and yield of DNA synthesis primed by viral RNA with purified viral polymerase. It specifically affects the viral polymerase and does not stimulate other DNA polymerases under the conditions tested. The viral polymerase, in conjunction with this protein, transcribes extended single-stranded regions of DNA, and permits the enzyme to initiate synthesis from single-strand breaks in DNA.