Cells were grown in BPYE medium with 25% bactopeptone, 20% yeast extract and 5% heat inactivated fetal calf serum. Expression plasmids for Dam-fusion and Dam-only proteins were transfected in parallel by electroporation, and cells were isolated 24 hr later. The Dam enzyme deposits stable adenine-methylation footprings at genomic sites bound by the Dam-fusion.
