Fig. 1
From: MRE11-RAD50-NBS1 complex alterations and DNA damage response: implications for cancer treatment
Structure and conformation of MRN complex. a Key domains of MRN complex subunits. Phosphoesterase domain of MRE11 has both single strand DNA endonuclease and double strand DNA exonuclease activity. Antiparallel coiled-coil domain of RAD50 extends the protein. Zinc hook domain of RAD50 facilitates the formation of dimers as depicted in (b). b MRN complex goes through conformational changes when ABC-ATPase domains (A/B Walker motifs) binds to ATP and forms a head-to-tail dimer. This compact, rigid, and closed conformation blocks access to MRE11 active sites. Upon hydrolysis and removing of ATP, MRN complex switches to an open form, exposing the active sites of MRE11. (FHA: fork-head associated domain; BRCT: breast cancer-associated 1 C domain)