Journal article
Monovalent cation localization in DNA A-tracts with different sequences
Electrophoresis, Vol.44(17-18), pp.1414-1422
09/01/2023
DOI: 10.1002/elps.202300063
PMID: 37354056
Appears in UI Libraries Support Open Access
Abstract
The free solution mobilities of 26-base pair (bp) DNA oligomers containing A-tracts with and without internal ApT steps have been measured by capillary electrophoresis, using the mobility of a 26-bp random-sequence oligomer as a reference. The background electrolytes (BGEs) contained mixtures of Li+ and tetrapropylammonium (TPA(+)) ions, keeping the total cation concentration constant at 0.3 M. The mobility ratios equaled 1.00 in 0.3 M TPA(+), indicating that the A-tract and reference oligomers had the same B-form conformation in this BGE. With increasing [Li+], the mobility ratio decreased as Li+ ions became localized in the A-tract minor groove, suggesting that the A-tract was now in the B* conformation. If the A-tract contained an internal ApT step and the oligomer contained less than & SIM;50% A + T, the mobility ratio reached a reduced plateau value that remained constant as the [Li+] increased to 0.3 M. However, for A-tracts without an internal ApT step and for A-tracts embedded in oligomers containing more than 50% A + T, the mobility ratios increased again at high [Li+], eventually reaching a plateau value of 1.00. Hence, DNA A-tracts in solution appear to exist as mixtures of the B and B* conformations, with the fractional concentration of each conformer depending on the [Li+], the A-tract sequence, and the total A + T content of the oligomer.
Details
- Title: Subtitle
- Monovalent cation localization in DNA A-tracts with different sequences
- Creators
- Earle Stellwagen - University of Iowa, Biochemistry and Molecular BiologyNancy. C. C. Stellwagen - University of Iowa, Biochemistry and Molecular Biology
- Resource Type
- Journal article
- Publication Details
- Electrophoresis, Vol.44(17-18), pp.1414-1422
- DOI
- 10.1002/elps.202300063
- PMID
- 37354056
- NLM abbreviation
- Electrophoresis
- ISSN
- 0173-0835
- eISSN
- 1522-2683
- Publisher
- Wiley
- Number of pages
- 9
- Grant note
- GM61009 / National Institute of General Medical Sciences; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA; NIH National Institute of General Medical Sciences (NIGMS)
- Language
- English
- Date published
- 09/01/2023
- Academic Unit
- Biochemistry and Molecular Biology
- Record Identifier
- 9984472859402771
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