Crystal Structure of the DNA Binding Domain of the Heat Shock Transcription Factor

作者：Celia J. Harrison, Alex Böhm, Hillary C.M. Nelson · 发表于：Science · 年份：1994 · DOI：10.1126/science.8284672 · 被引用次数：272 · 研究领域：Heat shock proteins research、RNA Research and Splicing、Protein Structure and Dynamics

The structure of the DNA binding domain, determined at 1.8 angstrom resolution, contains a three-helix bundle that is capped by a four-stranded antiparallel beta sheet. This structure is a variant of the helix-turn-helix motif, typified by catabolite activator protein. In the heat shock transcription factor, the first helix of the motif (alpha 2) has an alpha-helical bulge and a proline-induced kink. The angle between the two helices of the motif (alpha 2 and alpha 3) is about 20 degrees smaller than the average for canonical helix-turn-helix proteins. Nevertheless, the relative positions of the first and third helices of the bundle (alpha 1 and alpha 3) are conserved. It is proposed here that the first helix of the three-helix bundle be considered a component of the helix-turn-helix motif.