Equilibrium between a wobble and ionized base pair formed between fluorouracil and guanine in DNA as studied by proton and fluorine NMR

A synthetic oligonucleotide duplex containing the chemotherapeutic and mutagenic agent 5-fluorouracil paired with guanine has been studied in solution by proton and fluorine NMR. The 7-mer duplex containing a central FU.G base pair adopts a normal right-handed configuration. At low pH, the predomina...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of biological chemistry 1988-10, Vol.263 (29), p.14794-14801
Main Authors: Sowers, L C, Eritja, R, Kaplan, B, Goodman, M F, Fazakerly, G V
Format: Article
Language:English
Subjects:
Base Composition
Biological and medical sciences
DNA
Fluorine
Fluorouracil
Fundamental and applied biological sciences. Psychology
Guanine
Hydrogen-Ion Concentration
Interactions. Associations
Intermolecular phenomena
Kinetics
Magnetic Resonance Spectroscopy - methods
Molecular biophysics
Molecular Structure
Nucleic Acid Conformation
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A synthetic oligonucleotide duplex containing the chemotherapeutic and mutagenic agent 5-fluorouracil paired with guanine has been studied in solution by proton and fluorine NMR. The 7-mer duplex containing a central FU.G base pair adopts a normal right-handed configuration. At low pH, the predominant base-paired structure is wobble, whereas at higher pH an ionized structure in Watson-Crick geometry is observed. The two structures are in a pH-dependent equilibrium with one another with an apparent pK of 8.3 at 23 degrees C. This is the first demonstration of an equilibrium between two distinct base pairing schemes and the first demonstration of a negatively charged base pair in DNA.
ISSN:0021-9258
1083-351X
DOI:10.1016/S0021-9258(18)68108-6