DNA-binding protein involved in homologous recombination that acts by recruiting the MCM8-MCM9 helicase complex to sites of DNA damage to promote DNA repair synthesis. Interacts with MCM8; this interaction is necessary for MCM8-MCM9 helicase complex recruitment to DNA damage sites (By similarity). Interacts with RPA1; this interaction associates HROB with the RPA complex (PubMed:31467087). Localized to the sites of DNA damage. Deficient female and male mice exhibit infertility associated with impaired ovarian development and arrested male meiosis.