We have determined the structure of the DNA binding domain of the heat shock transcription factor (HSF) from Kluyveromyces lactis. Given the 1.05 E resolution of the structure, there are many detailed questions that can be addressed. First, we are interested in an unusual helix that contains a proline (which causes a kink) and an extra amino acid (which causes a bulge). Crystals have been obtained that have an alanine instead of the proline and the structure determination is underway. Second, we are interested in how the protein binds DNA. Crystals have been obtained of a complex between the DNA binding domain and its cognate binding site. The data collected on beamline 7-1 was used along with MAD data collected on 1-5 to determine the structure of the complex.