Hybridization of RNA to double-stranded DNA: formation of R-loops - PubMed (original) (raw)

Hybridization of RNA to double-stranded DNA: formation of R-loops

M Thomas et al. Proc Natl Acad Sci U S A. 1976 Jul.

Abstract

RNA can hybridize to double-stranded DNA in the presence of 70% formamide by displacing the identical DNA strand. The resulting structure, called an R-loop, is formed in formamide probably because of the greater thermodynamic stability of the RNA-DNA hybrid when it is near the denaturation temperature of duplex DNA. The rate of R-loop formation is maximal at the temperature at which half of the duplex DNA is irreversibly converted to single-stranded DNA (the strand separation temperature of tss) of the duplex DNA and falls precipitously a few degrees above or below that temperature. This maximal rate is similar to the rate of hybridization of RNA to single-stranded DNA under the same conditions. At temperatures above the tss the rate is proportional to the RNA concentration. However, at temperatures below tss the rate of R-loop formation is less dependent upon the RNA concentration. Once formed, the R-loops display considerable stability; the formamide can be removed and the DNA can be cleaved with restriction endonucleases without loss of R-loop structures.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Proc Natl Acad Sci U S A. 1972 Mar;69(3):737-41 - PubMed
    1. Proc Natl Acad Sci U S A. 1974 Nov;71(11):4579-83 - PubMed
    1. J Mol Biol. 1970 Feb 28;48(1):1-22 - PubMed
    1. Eur J Biochem. 1975 Oct 1;58(1):51-7 - PubMed
    1. J Mol Biol. 1968 Feb 14;31(3):349-70 - PubMed

MeSH terms

Substances

LinkOut - more resources