DNA-RNA hybrid duplexes containing oligo(dA:rU) sequences are exceptionally unstable and may facilitate termination of transcription

Nucleic Acids Res. 1980 May 24;8(10):2295-9. doi: 10.1093/nar/8.10.2295.


A DNA-RNA hybrid oligonucleotide duplex, dC(pA) 5pG:rC(pU)5pG, which contains a (dA:rU) 5 sequence, is at least 200 times less stable at room temperature than the corresponding duplex containing an (rA:dT) 5 sequence, rC(pA)5pG:dC(pT)5pG. This result provides an explanation for the finding that most primary RNA transcripts terminate in several consecutive rU residues, but not rA residues. It strongly supports the idea that instability of the DNA-RNA hybrid at the growing point of transcription plays a role in termination of transcription.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Base Sequence
  • DNA / metabolism*
  • Deoxyadenosines
  • Hot Temperature
  • Nucleic Acid Conformation
  • Nucleic Acid Hybridization*
  • Oligonucleotides
  • RNA / metabolism*
  • Transcription, Genetic*
  • Uracil


  • Deoxyadenosines
  • Oligonucleotides
  • Uracil
  • RNA
  • DNA