Members of this family adopt a winged-helix fold, with an alpha/beta structure consisting of three alpha-helices and a twisted three-stranded antiparallel beta-sheet, with an alpha-beta-alpha-alpha-beta-beta connectivity. They are involved in both DNA and RNA binding [1].

1: Crystal structure of an mRNA-binding fragment of Moorella thermoacetica elongation factor SelB. Selmer M, Su XD; EMBO J. 2002;21:4145-4153. PMID:12145214