Interaction of the oncogene protein myc with specific DNA fragments

The p110^gag-myc protein coded for by the retrovirus MC29 was purified 3,000-fold from MC29-Q8 transformed cells by immuno-affinity chromatography using IgG specific for the N-terminal region of the gag protein. Interaction of the protein with DNA fragments was studied by filter binding assay. DNA fragments were obtained from a MC29 DNA clone by restriction endonuclease treatment. Besides the complete DNA provirus the clone contained flanking cellular sequences into which the provirus had integrated. The DNA fragments which were retained by the p110^gag-myc protein were eluted from the filter and analyzed by agarose gel electrophoresis. Preferential binding of a DNA fragment originating from the flanking cellular sequences was detected. The protein did not preferentially bind to the viral LTR promoter/enhancer region as suggested by an autoregulatory model, which can therefore no longer be substantiated.