Figure 2.

The human ATM, γ-H2AX and mediator proteins. Key molecules involved in the double-stranded-break (DSB) response. Known structural domains for each protein are indicated. The ATM and RAD3-related (ATR)-related region in ATM is of unknown function. 53BP1, p53-binding protein 1; ATM, ataxia telangiectasia mutated; BRCA1, breast-cancer-associated protein 1; BRCT, BRCA1 carboxy terminal; FAT, FRAP/ATM/TRRAP; FATC, FAT carboxy terminal; FHA, fork-head associated; MDC1, mediator of DNA damage checkpoint protein 1; PI(3) kinase, phosphatidylinositol-3-OH kinase.