C:5-OH-U pair

FULL NAME: 5-OH-U from C:5-OH-U mismatch


DESCRIPTION:
NMR studies, UV-monitored melting experiments, and ab initio calculations show that 5-hydroxyuracil, produced by the oxidative de-amination of cytosines by reactive oxygen species, can form stable base-pairs with dA, dG, dC and dT residues in a DNA duplex, providing a basis for the in-vivo incorporation of 5-hydroxyuracil during DNA replication. Oxidized cytosine product 5-hydroxyuracil has been shown to be the major chemical precursor for the GC to AT transition, the most frequent substitution mutation observed in aerobic organisms. The hydroxyl group of 5-HO-U (relative to U) has little effect on the base-pairs with A, C or one conformation of T, while making a substantial energy difference in base-pairs involving G or a different conformation of T.

DAMAGE TYPE: mismatch


DNA DAMAGE SOURCE(S) (MAIN):
reactive oxygen species (ROS)
DNA replication errors
ionizing radiation (IR)


DNA DAMAGE SOURCE(S) (MINOR):
spontaneous deamination


DNA DAMAGE EFFECT(S) (MAIN):
mutagenesis
point mutation


Last modification date: Oct. 10, 2011