Theoretical study of a new DNA structure: the antiparallel Hoogsteen duplex

TitleTheoretical study of a new DNA structure: the antiparallel Hoogsteen duplex
Publication TypeJournal Article
Year of Publication2003
AuthorsCubero, E, Abrescia NG, Subirana JA, Luque FJ, Orozco M
JournalJournal of the American Chemical Society
Pagination14603 - 14612
Date Published2003/11/26/
KeywordsDNA/chemistry; Models, Molecular; Nucleic Acid Conformation; Poly dA-dT/chemistry; Solutions; Thermodynamics; Water/chemistry
AbstractThe structure of a new form of duplex DNA, the antiparallel Hoogsteen duplex, is studied in polyd(AT) sequences by means of state-of-the-art molecular dynamics simulations in aqueous solution. The structure, which was found to be stable in all of the simulations, has many similarities with the standard Watson-Crick duplex in terms of general structure, flexibility, and molecular recognition patterns. Accurate MM-PB/SA (and MM-GB/SA) analysis shows that the new structure has an effective energy similar to that of the B-type duplex, while it is slightly disfavored by intramolecular entropic considerations. Overall, MD simulations strongly suggest that the antiparallel Hoogsteen duplex is an accessible structure for a polyd(AT) sequence, which might compete under proper experimental conditions with normal B-DNA. MD simulations also suggest that chimeras containing Watson-Crick duplex and Hoogsteen antiparallel helices might coexist in a common structure, but with the differential characteristics of both type of structures preserved.