Related Experiment Video
Updated: Jul 18, 2026

Visualizing and Quantifying Endonuclease-Based Site-Specific DNA Damage
Published on: August 21, 2021
Activity of nucleotide excision repair enzymes for oxanine cross-link lesions
Toshiaki Nakano1, Atsushi Katafuchi, Hiroaki Terato
1Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan.
Abstract:
Nitric oxide and nitrous acid induce deamination of DNA bases, resulting in uracil, hypoxanthine, xanthine, and oxanine (Oxa) as major damage. Oxa reacts further with polyamines and DNA binding proteins, generating bulky cross-link adducts. Recently we have shown Oxa and cross-link adducts are potentially genotoxic lesions. In the present study, we have assessed the role of base excision repair (BER) and nucleotide excision repair (NER) systems in the repair of Oxa and Oxa-spermine (Oxa-Sp) cross-link adducts. Oxa was very poorly removed from DNA by both BER glycosylases and NER enzymes, whereas Oxa-Sp was efficiently excised by E. coli and human NER enzymes.
Related Concept Videos
Nucleotide Excision Repair
Nucleotide Excision Repair
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
Nucleotide Excision Repair
Long-patch Base Excision Repair
Base Excision Repair
The first step of...
Base Excision Repair
The first step of...
