Members of this family adopt a structure consisting of three alpha helices and a beta-hairpin. They bind to TATA box-binding protein (TBP), inhibiting TBP interaction with the TATA element, thereby resulting in shutting down of gene transcription [1].

1: Solution structure of a TBP-TAF(II)230 complex: protein mimicry of the minor groove surface of the TATA box unwound by TBP. Liu D, Ishima R, Tong KI, Bagby S, Kokubo T, Muhandiram DR, Kay LE, Nakatani Y, Ikura M; Cell. 1998;94:573-583. PMID:9741622