This domain is the zinc-binding domain of ATP-dependent DNA helicase RecQ [1-2].

1: High-resolution structure of the E.coli RecQ helicase catalytic core. Bernstein DA, Zittel MC, Keck JL; EMBO J. 2003;22:4910-4921. PMID:14517231

2: Structure of the human RECQ1 helicase reveals a putative strand-separation pin. Pike AC, Shrestha B, Popuri V, Burgess-Brown N, Muzzolini L, Costantini S, Vindigni A, Gileadi O; Proc Natl Acad Sci U S A. 2009;106:1039-1044. PMID:19151156