For the oligonucleotide competition assays, 10 ng of 32P-end-labeled double-stranded oligonucleotide was incubated with 100 ng of GST-fusion protein bound to glutathione beads in the Lambda DNA-binding buffer containing 50 mM KCl, 100 μg of salmon sperm DNA and varying amounts of unlabeled double-stranded competitor oligonucleotide, as indicated in the text. The beads were washed and the bound DNA was eluted and visualized as described above.
