SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily A containing DEAD/H box 1 (SMARCAD1, also known as ATP-dependent helicase 1 or Hel1) possesses intrinsic ATP-dependent nucleosome-remodeling activity and is required for both DNA repair and heterochromatin organization. SMARCAD1 is a member of the DEAD-like helicase superfamily, a diverse family of proteins involved in ATP-dependent RNA or DNA unwinding. This domain contains the ATP-binding region.