Structure-specific DNA-binding protein with a preference for cruciform structures. Also binds single-stranded DNA (ssDNA). Functions together with SGS1 and TOP3 to maintain genome integrity. Essential for proper meiotic cell division. Required for normal S-phase progression and DNA damage response. Required for resistance to the DNA-damaging agent methyl methanesulfonate (MMS). Forms a complex with SGS1 and TOP3. Present with 1500 molecules/cell in log phase SD medium. Belongs to the RMI1 family.