SPECTROSCOPIC PROBE FOR THE DETECTION OF LOCAL DNA BENDING AT AN AAA TRIPLET

Citation
Ev. Bobst et al., SPECTROSCOPIC PROBE FOR THE DETECTION OF LOCAL DNA BENDING AT AN AAA TRIPLET, Biochemistry, 35(29), 1996, pp. 9309-9313
Citations number
36
Categorie Soggetti
Biology
Journal title
ISSN journal
00062960
Volume
35
Issue
29
Year of publication
1996
Pages
9309 - 9313
Database
ISI
SICI code
0006-2960(1996)35:29<9309:SPFTDO>2.0.ZU;2-T
Abstract
Spectroscopic evidence of a DNA bend in solution is presented by analy zing model 15-mer duplexes spin-labeled with the five-atom-tethered ni troxide DUAP located in the major groove. Three 15-mers containing AAT T with DUAP enzymatically incorporated into three different positions yielded nearly identical line shapes while a fourth 15-mer containing AAATT produced an EPR spectrum with significant additional line broade ning. These results are interpreted according to the dynamic cylinder model where the DNA dynamics are decoupled into overall and internal c ontributions. It is shown that the AAATT sequence induces a change in the internal dynamics characterized by local ordering of DUAP. The inc rease in ordering evident in 15-mers containing AAATT rather than AATT suggests that the former sequence gives rise to a bend toward the maj or groove resulting in spatial restriction of the probe.