DNA-dependent ATPase and 3'-5' DNA helicase that may be involved in repair of stalled replication forks. ATP + H2O = ADP + H(+) + phosphate Monomer. This protein undergoes a protein self splicing that involves a post-translational excision of the intervening region (intein) followed by peptide ligation. Belongs to the helicase family. Hel308 subfamily.