Increasing occurrences and functional roles for high energy purine-pyrimidine base-pairs in nucleic acids.

Journal Article (Journal Article;Review)

There are a growing number of studies reporting the observation of purine-pyrimidine base-pairs that are seldom observed in unmodified nucleic acids because they entail the loss of energetically favorable interactions or require energetically costly base ionization or tautomerization. These high energy purine-pyrimidine base-pairs include G•C(+) and A•T Hoogsteen base-pairs, which entail ∼180° rotation of the purine base in a Watson-Crick base-pair, protonation of cytosine N3, and constriction of the C1'-C1' distance by ∼2.5Å. Other high energy pure-pyrimidine base-pairs include G•T, G•U, and A•C mispairs that adopt Watson-Crick like geometry through either base ionization or tautomerization. Although difficult to detect and characterize using biophysical methods, high energy purine-pyrimidine base-pairs appear to be more common than once thought. They further expand the structural and functional diversity of canonical and non-canonical nucleic acid base-pairs.

Full Text

Duke Authors

Cited Authors

  • Kimsey, I; Al-Hashimi, HM

Published Date

  • February 2014

Published In

Volume / Issue

  • 24 /

Start / End Page

  • 72 - 80

PubMed ID

  • 24721455

Pubmed Central ID

  • PMC4048017

Electronic International Standard Serial Number (EISSN)

  • 1879-033X

Digital Object Identifier (DOI)

  • 10.1016/


  • eng

Conference Location

  • England