Nuclear factor I represses the reverse-oriented transcription from the adenovirus type 5 DNA terminus

The promoter activity of a cloned inverted terminal repeat (ITR) of human adenovirus (Ad) type 5 was found to be oriented in the opposite direction with respect to that of DNA replication in a cell-free transcription system using HeLa nuclear extracts. The major transcript was initiated outside the Ad sequence about 30 nucleotides downstream from the putative TATA-box located between nucleotide positions 9-18 of Ad 5 left terminus. Competitive transcription experiments using double-stranded oligonucleotides and isolated nuclear factor I revealed that nuclear factor I and its cognate binding site located upstream of the putative TATA-box are involved in negative regulation of the transcription from ITR promoter.