The standard view of the genome is that the two DNA strands are linked by Watson–Crick base pairing. Some deviations from this canonical pairing have been observed when DNA is bound to a ligand. This paper now shows that naked DNA itself can transiently adopt a Hoogsteen base-pairing arrangement. This excited state base pairing provides a means to expand the chemistry and structure of DNA, and has implications for the binding of proteins to and repair of DNA.
- Evgenia N. Nikolova
- Eunae Kim
- Hashim M. Al-Hashimi