DNA base modification: Ionized base pairs and mutagenesis

Lawrence C. Sowers, Barbara Ramsay Shaw, Martina L. Veigl, W. David Sedwick

Research output: Contribution to journalArticlepeer-review

102 Scopus citations


The nature of hydrogen bonding between normal and modified bases has been re-examined. It is proposed that hydrogen-bonding schemes may involve tautomeric, ionized or conformational forms (syn, anti and wobble). Several important cases are presented or reviewed in which physical evidence indicates the existence of ionized base pairs. When thermodynamic values determined in aqueous solution under physiological conditions are considered, it can be argued that base ionization will contribute substantially to the stability of many biologically relevant base pairs containing modified bases. A significant incidence of ionized bases in DNA may have important kinetic ramifications for the further chemical reactivity of both the modified base and its cross-strand pairing partner. Moreover, DNA structure at and surrounding ionized base pairs may be altered. For this reason, the model presented in this study should be useful as DNA-sequence analysis becomes more commonly applied to the study of mutagenesis.

Original languageEnglish (US)
Pages (from-to)201-218
Number of pages18
JournalMutation Research - Fundamental and Molecular Mechanisms of Mutagenesis
Issue number2
StatePublished - Apr 1987
Externally publishedYes


  • DNA base modification
  • Hydrogen bonding
  • Ionized base pairs

ASJC Scopus subject areas

  • Molecular Biology
  • Genetics
  • Health, Toxicology and Mutagenesis


Dive into the research topics of 'DNA base modification: Ionized base pairs and mutagenesis'. Together they form a unique fingerprint.

Cite this