Inhibition of in Vitro Transcription by Oligodeoxynucleotides

Abstract

Single-stranded short phosphodiester oligodeoxynucleotides have been used to inhibit in vitro T7 transcription system. These oligodeoxynucleotides were complementary to either the 3′-5′ or 5′-3′ strand of the transcription initiation site of a plasmid containing the gag region of HIV. Our results show that incubation of this plasmid DNA with the oligodeoxynucleotide complementary to the template DNA strand (3′-5′, sense oligo) showed efficient inhibition of transcription. Incubation of this plasmid with the oligodeoxynucleotide complementary to the 5′-3′ strand (antisense oligo) or a random oligodeoxynucleotide failed to do so. The inhibition of gag transcription was specific since the sense oligo failed to prevent transcription of a plasmid containing U2 RNA sequences. The inhibition of transcription was not limited to T7 RNA polymerase but was also observed with SP6 RNA polymerase.