PEPTIDE NUCLEIC-ACID DNA STRAND DISPLACEMENT LOOPS AS ARTIFICIAL TRANSCRIPTION PROMOTERS

Homopyrimidine peptide nucleic acids (PNAs) form loop structures when binding to complementary double-stranded DNA by strand displacement, a nd we now show that RNA polymerase recognizes these and initiates RNA transcription from RNA/double-stranded DNA strand displacement complex es at an efficiency comparable to that of the strong Escherichia coli lacUV5 promoter. Thus PNA targets can be considered as artificial prom oters controlled positively by the corresponding PNA as a transcriptio n factor. Our results have implications for the mechanism of action of RNA polymerase and suggest the use of RNA as specific gene activating reagents and drugs.