We study how the Hox family of transcription factors bind to the correct DNA sequences and regulate the correct target genes in vivo.
The Hox genes encode a conserved family of homeodomain-containing transcription factors that specify tissue and cellular identities throughout the animal kingdom. As is typical for homeodomain proteins, they tend to bind a wide range of degenerate, TAAT-containing binding sites, raising the fundamental question of how these factors achieve specificity in vivo. We use a variety of approaches, including whole genome binding studies, in vitro DNA binding assays, X-ray crystallography, in vivo functional tests, and high-throughput DNA specificity measurements, to address this question. Our most recent work (Slattery et al., 2011) reveals that Hox cofactors reveal “latent specificity” that is present in the Hox homeodomain, but cannot be used in the absence of the cofactors. In one specific case (Scr; Joshi et al., 2007) we found that latent specificity allows normally unstructured residues in the Hox protein Scr to read a DNA shape: the width of the minor groove.
Current lab members working on this project: Bill Glassford, Siqian Feng, Judith Kribelbauer, Ryan Loker, and Rebecca Delker (collaborations with Barry Honig and Harmen Bussemaker).