Synthesis of DNA by Micrococcus luteus is resistant to 6-(p-hydroxyphenylazo)uracil

The DNA synthesis inhibitor 6-(p-hydroxyphenylazo)uracil (HPUra), at concentrations ranging from 0.2 to 2000 micro M, had essentially no effect on DNA synthesis in Micrococcus luteus strain ML-1. Seven other M. luteus strains were unaffected by 200 micro M HPUra. In vitro DNA synthesis in toluene-treated M. luteus strain ML-1 ws resistant to both HPUra and reduced HPUra.