Component of the MCM8-MCM9 complex, a complex involved in homologous recombination repair following DNA interstrand cross-links and plays a key role during gametogenesis. The MCM8-MCM9 complex probably acts as a hexameric helicase required to process aberrant forks into homologous recombination substrates and to orchestrate homologous recombination with resection, fork stabilization and fork restart. In eggs, required for elongation during DNA replication by facilitating the recruitment of rpa2/rpa34 and stimulating the processivity of DNA polymerases at replication foci. Probably not required for DNA replication in other cells (By similarity). ATP + H2O = ADP + H(+) + phosphate Component of the MCM8-MCM9 complex, which forms a hexamer composed of mcm8 and mcm9. Localizes to nuclear foci and colocalizes with rad51. Belongs to the MCM family.