Complexities of the DNA base excision repair pathway for repair of oxidative DNA damage

Sankar Mitra, Istvan Boldogh, Tadahide Izumi, Tapas K. Hazra

Research output: Contribution to journalArticlepeer-review

118 Scopus citations


Oxidative damage represents the most significant insult to organisms because of continuous production of the reactive oxygen species (ROS) in vivo. Oxidative damage in DNA, a critical target of ROS, is repaired primarily via the base excision repair (BER) pathway which appears to be the simplest among the three excision repair pathways. However, it is now evident that although BER can be carried with four or five enzymes in vitro, a large number of proteins, including some required for nucleotide excision repair (NER), are needed for in vivo repair of oxidative damage. Furthermore, BER in transcribed vs. nontranscribed DNA regions requires distinct sets of proteins, as in the case of NER. We propose an additional complexity in repair of replicating vs. nonreplicating DNA. Unlike DNA bulky adducts, the oxidized base lesions could be incorporated in the nascent DNA strand, repair of which may share components of the mismatch repair process. Distinct enzyme specificities are thus warranted for repair of lesions in the parental vs. nascent DNA strand. Repair synthesis may be carried out by DNA polymerase β or replicative polymerases δ and ε. Thus, multiple subpathways are needed for repairing oxidative DNA damage, and the pathway decision may require coordination of the successive steps in repair. Such coordination includes transfer of the product of a DNA glycosylase to AP-endonuclease, the next enzyme in the pathway. Interactions among proteins in the pathway may also reflect such coordination, characterization of which should help elucidate these subpathways and their in vivo regulation.

Original languageEnglish
Pages (from-to)180-190
Number of pages11
JournalEnvironmental and Molecular Mutagenesis
Issue number2-3
StatePublished - 2001


  • Base excision repair
  • Coordination of repair pathway
  • Oxidative DNA damage
  • Reactive oxygen species
  • Replication-associated repair

ASJC Scopus subject areas

  • Epidemiology
  • Genetics(clinical)
  • Health, Toxicology and Mutagenesis


Dive into the research topics of 'Complexities of the DNA base excision repair pathway for repair of oxidative DNA damage'. Together they form a unique fingerprint.

Cite this