This domain is predicted to bind metal ions [1] and is often found associated with Pfam:PF00533 and Pfam:PF02178. It was first identified in the Drosophila chiffon gene product [2], and is associated with initiation of DNA replication.

1: Systematic identification of novel protein domain families associated with nuclear functions. Doerks T, Copley RR, Schultz J, Ponting CP, Bork P; Genome Res 2002;12:47-56. PMID:11779830

2: The Drosophila chiffon gene is required for chorion gene amplification, and is related to the yeast Dbf4 regulator of DNA replication and cell cycle. Landis G, Tower J; Development. 1999;126:4281-4293. PMID:10477296