This domain is found in Elongation factor SelB from Aquifex aeolicus and similar bacterial proteins. SelB is a selenocysteine(Sec)-specific elongation factor that brings the selenocysteinyl-tRNA(Sec) to the ribosome. It consists of three EF-Tu-like domains (D1-3, where Pfam:PF00009 is the first one), followed by four winged-helix domains (WHD1-4). This entry represents the third winged-helix domains (WHD3) [1].

1: Crystal structure of the full-length bacterial selenocysteine-specific elongation factor SelB. Itoh Y, Sekine S, Yokoyama S; Nucleic Acids Res. 2015;43:9028-9038. PMID:26304550