STRUCTURAL STUDY OF RAT-THYROID TRANSCRIPTION FACTOR 1 HOMEODOMAIN (TTF-1 HD) BY NUCLEAR-MAGNETIC-RESONANCE

The 500 MHz H-1 NMR spectrum of a 68-residue peptide, encompassing the rat thyroid transcription factor 1 homeodomain (TTF-1 HD), was fully assigned using standard 2D NMR methodology. The secondary structure el ements and their spatial organization were determined and led to a str ucture very similar to that previously described for other homeodomain s and expected also for TTF-1 HD from homology modeling predictions. T he three-dimensional arrangement of the three helix fragments of TTF-1 HD preserves the helix-turn-helix moth commonly occurring in many cla sses of DNA-binding proteins.