Structural Insights into the Sequence Preference of PU.1, a Conserved Helix-Turn-helix Transcription Factor

Winged helix-turn-helix (wHTH) proteins are ubiquitous DNA-binding motifs in all kingdoms of life. In eukaryotes, wHTH motifs are found in many transcription factors which recognize a wide range of cognate sequences; both high- and low-affinity binding being biologically important and non-interchangeable in vivo. To better understand the structural mechanisms through which wHTH containing proteins derive sequence selectivity, we are studying the ETS family of transcription factors. We focus on the protein PU.1 for structural examination owing to its broad range of DNA target preferences and affinities which set it apart from other ETS members.