Hoogsteen base pair

Chemical structures for Watson–Crick and Hoogsteen A•T and G•C+ base pairs. The Hoogsteen geometry can be achieved by purine rotation around the glycosidic bond (χ) and base-flipping (θ), affecting simultaneously C8 and C1′ (yellow).[1]

A Hoogsteen base pair is a variation of base-pairing in nucleic acids such as the A•T pair. In this manner, two nucleobases, one on each strand, can be held together by hydrogen bonds in the major groove. A Hoogsteen base pair applies the N7 position of the purine base (as a hydrogen bond acceptor) and C6 amino group (as a donor), which bind the Watson–Crick (N3–C4) face of the pyrimidine base.

  1. ^ Evgenia N. Nikolova; Eunae Kim; Abigail A. Wise; Patrick J. O'Brien; Ioan Andricioaei; Hashim M. Al-Hashimi (2011). "Transient Hoogsteen base pairs in canonical duplex DNA". Nature. 470 (7335): 498–502. Bibcode:2011Natur.470..498N. doi:10.1038/nature09775. PMC 3074620. PMID 21270796.