In vivo DMS footprinting of both DNA strands of the hEPCR promoter. (A) Analysis of lower strand (left panel) and upper strand (right panel). DMS methylation of naked genomic DNA (G) was compared with in vivo methylation of HepG2 (H) or EA.hy926 (E) DNA. A representative experiment with long and short gel runs from each primer set is presented. Potential binding sites for transcription factors are indicated at the right of each gel image. Positions relative to the ATG site are indicated at the left of each gel. Open circles (○) represent 3-fold or greater protection, and closed circles (•) represent 2-fold or greater enhancements of DMS reactivity of E and H relative to G. (B) DNA sequence of the hEPCR promoter from –396 bp to –97 bp with transcription factor binding sites and DMS protections/enhancements indicated as described in panel A. Boxed regions (I-V) indicate binding sites corroborated by EMSA. The dashed box indicates a putative binding site not identified by EMSA.