InterPro domain: IPR010003

SMARCAL1 (SWI/SNF-related, matrix-associated, actin-dependent regulator ofchromatin, subfamily A-like1), also known as DNA-dependent ATPase A and HARP(Hep-A-related proteins), maintains genome integrity during DNA replication.SMARCAL1 has ATP-dependent annealing helicase activity, which helps tostabilise stalled replication forks and facilitate DNA repair duringreplication. Biochemically, SMARCAL1 can bind to DNA that contains single- anddouble-stranded regions such as forks and DNA hairpins. DNA binding activatesits ATPase activity, and this activity promotes DNA single-stranded annealing[ 1 , 2 ].

SMARCAL1 is a multifunctional protein. The ATPase domain, which lies in the C-terminal half of the protein, is split into two regions of primary amino acidsequence by a 115-amino-acid linker sequence. The N-terminalhalf of the protein contains a highly sequence conserved ssDNA-binding proteinreplication protein A (RPA)-binding domain, and one or two HARP domain(s). Theevolutionarily conserved HARP domain determines the annealing helicaseactivity required for the in vivo and in vitro functions of SMARCAL1 [ 3 , 3 , 3 ].

1. The HARP domain dictates the annealing helicase activity of HARP/SMARCAL1. EMBO Rep. 12, 574-80
2. SMARCAL1 catalyzes fork regression and Holliday junction migration to maintain genome stability during DNA replication. Genes Dev. 26, 151-62
3. Cloning and characterization of HARP/SMARCAL1: a prokaryotic HepA-related SNF2 helicase protein from human and mouse. Genomics 65, 274-82