One- and two-dimensional 1H-NMR investigations of two 19-base-pair analogues of the tet operator.
Two 19-base-pair oligodeoxynucleotides, analogues of one of the operators which specifically bind the repressor protein in the regulatory part of the transposon Tn10 tetracycline-resistance (tet) determinant, have been studied by 1H-NMR spectroscopy. The analogues contain a mismatch in the central base pair of the double helix (T.T or A.A). The imino protons have been assigned to the base pairs by one-dimensional NOE measurements, and the thermally induced transition from the duplex to the single strand has been followed. The cytidine amino resonances have been assigned by means of two-dimensional NOE spectroscopy in H2O. Two-dimensional phase-sensitive NOE and magnitude-correlated spectra have been recorded in 2H2O; all nonexchangeable protons, with the exception of some of H5', H5" protons, have been assigned. The NMR data made it possible to carry out a qualitative analysis of the structures of both oligodeoxynucleotides. The general structures close to B-DNA, show irregularities in the mismatch areas.
Institute of Biophysical Chemistry, J. W. Goethe University, Frankfurt, Federal Republic of Germany.
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Stolarski
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Buck
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Fera
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Rüterjans
D001483:Base Sequence; D009682:Magnetic Resonance Spectroscopy; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides; D009876:Operon; D012097:Repressor Proteins / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
D009838:Oligodeoxyribonucleotides; D012097:Repressor Proteins; D014157:Transcription Factors; C034811:tetracycline resistance-encoding transposon repressor protein