DNase I footprint analysis of the GPV promoter fragment III using Dami and HeLa cell extracts. The 5′-end-labeled fragment III (nt −1119 to −633) was incubated with 50 μg HeLa or Dami nuclear extract in the presence of 2 μg poly(dIdC).poly(dIdC) and digested with 1, 2, or 3 U DNase I. Control corresponds to digestion of III with 0.6 or 1.2 U DNase I in the absence of nuclear extract. Digestion products were separated on an 8% acrylamide sequencing gel in the presence of 8 mol/L urea, and bands were compared with those of a DNA molecular weight marker (Hpa II digest of pBR-322). The protected regions are indicated on the right and named according to their homology with known transcription factor binding sites (“GATA” and “Ets” for putative binding sites for GATA and Ets transcription factors). The corresponding protected nucleotide sequences are indicated in the lower part of the figure and the consensus binding sites are underlined and in bold characters.