A nonradioactive automated protocol to study protein-DNA interactions by dnase-I footprinting

Regulation of gene expression is operated, at transcriptional level, by the interactions between proteins (transcription factors) and elements present within eukaryotic and viral promoters (transcription signals) exhibiting specific nucleotide sequences. In this study we performed DNase I cleavage and analysis of the cleavage products using the Pharmacia ALF(TM) DNA sequencing system. As model system we employed the long terminal repeat (LTR) of the human immunodeficiency type I (HIV-1) virus, containing the DNA sequences recognized by a number of transcription factors, including NF-kB, Sp1 and TFIID. The main conclusion of our experiments is that automated analysis of DNAse I footprinting employing the ALF DNA sequencing system is a fast and reliable technique to study protein-DNA interactions.