Polymorphisms in base excision repair genes: Breast cancer risk and individual radiosensitivity

Figure 1 Base-excision repair. Simplified schematic representation of the short-patch base-excision repair pathway showing the key steps and main proteins involved in the repair of a damaged DNA base. Adapted from Costa et al[8]. OGG1: 8-oxoguanine DNA glycosylase 1; APE1: Apurinic/apyrimidinic endonuclease 1; PARP-1: Poly (ADP-ribose) polymerase-1; XRCC1: X-ray repair cross complementing group 1; Polβ: DNA polymerase-β; LIGIII: DNA ligase III.

Figure 2 Domains of the X-ray repair cross-complementing group 1 protein and X-ray repair cross-complementing group 1 gene structure. A: The schematic diagram shows the regions of interaction with other base excision repair proteins; B: The diagram shows the structure of XRCC1 with the locations of the most common and well-studied single nucleotide polymorphisms: 77 T > C, Arg194Trp, Arg280His and Arg 399Gln. Modified from Sterpone et al[14]. XRCC1: X-ray repair cross-complementing group 1; OGG1: 8-oxoguanine DNA glycosylase 1; APE1: Apurinic/apyrimidinic endonuclease 1; PARP-1: Poly (ADP-ribose) polymerase-1; Polβ: DNA polymerase-β; LIGIII: DNA ligase III; NTD: N-terminal domain; NLS: Nuclear localisation signal; BRCT: BRCA1 carbox-terminal domain.