– DNA helicase that stimulates viral DNA replication and recombination. Plays a role in T4 DNA replication initiation by selecting and activating DNA origins. Acts by dissociating and reassociating with the DNA molecule being unwound. Unwinds DNA as a monomer in a 5′-to-3′ direction at a rate of 250 bp/s and can efficiently displace proteins from the DNA. ATP-dependent DNA helicase dda Protein, Enterobacteria phage T4, Recombinant (His) is expressed in E. coli expression system with N-6xHis tag. The predicted molecular weight is 54.0 kDa and the accession number is P32270.