Weinfeld, M., Rasouli-Nia, A., Chaudhry, M. A. and Britten, R. A. Response of Repair Enzymes to Complex DNA Lesions. Radiat. Res. 156, 584–589 (2001).

There is now increasing evidence that ionizing radiation generates complex DNA damage, i.e. two or more lesions—single-strand breaks or modified nucleosides—located within one to two helical turns on the same strand or on opposite strands. Double-strand breaks are the most readily recognizable clustered lesions, but they may constitute a relatively minor fraction of the total. It is anticipated that clustered lesions may play a significant role in cellular response to ionizing radiation since they may present a major challenge to the DNA repair machinery. The degree of lesion complexity increases with increasing LET. This has potential implications for space travel because of exposure to high-LET cosmic radiation. It is therefore critical that we begin to understand the consequences of such damaged sites, including their influence on DNA repair enzymes. This paper presents a short review of our current knowledge of the action of purified DNA repair enzymes belonging to the base excision repair pathway, including DNA glycosylases and apurinic/apyrimidinic endonucleases, on model complex lesions.