Component of the MCM8-MCM9 complex, a complex involved in the repair of double-stranded DNA breaks (DBSs) and DNA interstrand cross-links (ICLs) by homologous recombination (HR). Required for DNA resection by the MRE11-RAD50-NBN/NBS1 (MRN) complex by recruiting the MRN complex to the repair site and by promoting the complex nuclease activity. Probably by regulating the localization of the MNR complex, indirectly regulates the recruitment of downstream effector RAD51 to DNA damage sites including DBSs and ICLs. The MCM8-MCM9 complex is dispensable for DNA replication and S phase progression. However, may play a non-essential for DNA replication: may be involved in the activation of the prereplicative complex (pre-RC) during G(1) phase by recruiting CDC6 to the origin recognition complex (ORC). Probably by regulating HR, plays a key role during gametogenesis. Stabilizes MCM9 protein. ATP + H2O = ADP + H(+) + phosphate Component of the MCM8-MCM9 complex, which forms a hexamer composed of MCM8 and MCM9. Interacts with the DNA mismatch repair (MMR) complex composed at least of MSH2, MSH3, MSH6, PMS1 and MLH1. Interacts with RAD51; the interaction recruits RAD51 to DNA damage sites. Interacts with the MRN complex composed of MRE11, RAD50 and NBN/NBS1. Interacts with CDC6 and ORC2. Interacts with HROB; the interaction recruits the MCM8-MCM9 complex to DNA damage sites (By similarity). Localizes to nuclear foci. Localizes to double-stranded DNA breaks. Binds chromatin throughout the cell cycle. Belongs to the MCM family.