This is the conserved N-terminal winged helix domain of Storkhead-box1 protein which is likely to be a DNA binding domain. In humans the full-length protein controls polyploidization of extravillus trophoblast and is implicated in pre-eclampsia.

1: Maternal segregation of the Dutch preeclampsia locus at 10q22 with a new member of the winged helix gene family. van Dijk M, Mulders J, Poutsma A, Konst AA, Lachmeijer AM, Dekker GA, Blankenstein MA, Oudejans CB; Nat Genet. 2005;37:514-519. PMID:15806103