Has a role in spindle assembly which acts in the progression through mitosis during embryogenesis. Required for fertility. ATP + H2O = ADP + H(+) + phosphate At 25 degrees Celsius and pH 8.0. Optimum pH is 8.0-8.8. Optimum temperature is 25-30 degrees Celsius. Hexamer. Expressed in germ cells. Sterility owing to depletion of germ cells. Belongs to the AAA ATPase family.