ATP-dependent helicase/deoxyribonuclease subunit B (ADDB) forms a heterodimer with ADDA which acts as both an ATP-dependent DNA helicase and an ATP-dependent single-stranded exonuclease, acting in both directions. This entry represents the N-terminal domain of ADDB, which contains the Walker A motif involved in ATP binding [1,2].

1: Insights into Chi recognition from the structure of an AddAB-type helicase-nuclease complex. Saikrishnan K, Yeeles JT, Gilhooly NS, Krajewski WW, Dillingham MS, Wigley DB; EMBO J. 2012;31:1568-1578. PMID:22307084

2: Structural basis for translocation by AddAB helicase-nuclease and its arrest at chi sites. Krajewski WW, Fu X, Wilkinson M, Cronin NB, Dillingham MS, Wigley DB; Nature. 2014;508:416-419. PMID:24670664