C-terminal helicase domain of Fanconi anemia group M family helicases
Fanconi anemia group M (FANCM) protein is a DNA-dependent ATPase component of the Fanconi anemia (FA) core complex. It is required for the normal activation of the FA pathway, leading to monoubiquitination of the FANCI-FANCD2 complex in response to DNA damage, cellular resistance to DNA cross-linking drugs, and prevention of chromosomal breakage. Hef (helicase-associated endonuclease fork-structure) belongs to the XPF/MUS81/FANCM family of endonucleases and is involved in stalled replication fork repair. FANCM and Hef are DEAD-like helicases belonging to superfamily (SF)2, a diverse family of proteins involved in ATP-dependent RNA or DNA unwinding. Similar to SF1 helicases, SF2 helicases do not form toroidal structures like SF3-6 helicases. Their helicase core consists of two similar protein domains that resemble the fold of the recombination protein RecA. This model describes the C-terminal domain, also called HelicC.