Targeting of the Sp1 binding sites of HIV-1 long terminal repeat with chromomycin. Disruption of nuclear factor.DNA complexes and inhibition of in vitro transcription

Sequence selectivity of DNA-binding drugs has recently been reported in a number of studies employing footprinting and gel retardation approaches. In this paper, we studied the biochemical effects of the sequence-selective binding of chromomycin to the long terminal repeat of the human immunodeficiency type I virus. Deoxyribonuclease I (E.C.3.1.21.1) footprinting, arrested polymerase chain reaction, gel retardation and in vitro transcription experiments have demonstrated that chromomycin preferentially interacts with the binding sites of the promoter-specific transcription factor Sp1. Accordingly, interactions between nuclear proteins and Sp1 binding sites are inhibited by chromomycin, and this effect leads to a sharp inhibition of in vitro transcription.