This domain is found in the multiprotein bridging factor 1 (MBF1) which forms a heterodimer with MBF2. It has been shown to make direct contact with the TATA-box binding protein (TBP) and interacts with Ftz-F1, stabilizing the Ftz-F1-DNA complex. It is also found in the endothelial differentiation-related factor (EDF-1). Human EDF-1 is involved in the repression of endothelial differentiation, interacts with CaM and is phosphorylated by PKC. The domain is found in a wide range of eukaryotic proteins including metazoans, fungi and plants. A helix-turn-helix motif (pfam01381) is found to its C-terminus.