Thymidine glycol: the effect on DNA molecular structure and enzymatic processing.
Biochimie
; 95(2): 134-47, 2013 Feb.
Article
em En
| MEDLINE
| ID: mdl-23000318
ABSTRACT
Thymine glycol (Tg) in DNA is a biologically active oxidative damage caused by ionizing radiation or oxidative stress. Due to chirality of C5 and C6 atoms, Tg exists as a mixture of two pairs of cis and trans diastereomers 5R cis-trans pair (5R,6S; 5R,6R) and 5S cis-trans pair (5S,6R; 5S,6S). Of all the modified pyrimidine lesions that have been studied to date, only thymine glycol represents a strong block to high-fidelity DNA polymerases in vitro and is lethal in vivo. Here we describe the preparation of thymine glycol-containing oligonucleotides and the influence of the oxidized residue on the structure of DNA in different sequence contexts, thymine glycol being paired with either adenine or guanine. The effect of thymine glycol on biochemical processing of DNA, such as biosynthesis, transcription and repair in vitro and in vivo, is also reviewed. Special attention is paid to stereochemistry and 5R cis-trans epimerization of Tg, and their relation to the structure of DNA double helix and enzyme-mediated DNA processing. Described here are the comparative structure and properties of other forms of pyrimidine base oxidation, as well as the role of Tg in tandem lesions.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oligonucleotídeos
/
Timidina
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Dano ao DNA
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DNA
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Reparo do DNA
Limite:
Humans
Idioma:
En
Revista:
Biochimie
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Federação Russa