DNA-dependent ATPase (ssDNA better than dsDNA) and ATP-dependent 5'-3' DNA helicase. Appears to move along DNA in single base steps, powered by hydrolysis of 1 molecule of ATP. Has low processivity; short (20 bp) substrates with 5'-overhangs or forked ends are the best substrates, is much less efficient on 52 or 76 bp substrates with 5'- overhangs. The presence of single-stranded DNA-binding protein (SSB) increases unwinding 4-5 fold. Has no activity on blunt DNA or DNA with 3'-overhangs. Requires at least 10 bases of 5'-ssDNA for helicase activity. ATP + H2O = ADP + H(+) + phosphate Optimum pH is 6.3 to 6.5 for unwinding of a 56 bp substrate and DNA hairpin binding. There are no RecB or RecC orthologs in this organism. Belongs to the RecD family. RecD-like subfamily.