- The ataxia-oculomotor apraxia 1 gene product has a role distinct from ATM and interacts with the DNA strand break repair proteins XRCC1 and XRCC4. Clements, P.M., Breslin, C., Deeks, E.D., Byrd, P.J., Ju, L., Bieganowski, P., Brenner, C., Moreira, M.C., Taylor, A.M., Caldecott, K.W. DNA Repair (Amst.) (2004)