MULTIDIMENSIONAL NMR-SPECTROSCOPY OF DNA-BINDING PROTEINS - STRUCTUREAND FUNCTION OF A TRANSCRIPTION FACTOR

The solution structure of a type II DNA-binding protein (DBPII), trans cription factor 1 (TF1), has been determined using NMR spectroscopy. A multidimensional, heteronuclear strategy was employed to overcome ass ignment ambiguities due to resonance overlap and broadened crosspeaks. This approach involved the use of selectively deuteriated, C-13- and N-15-labeled samples and 'isotopic heterodimers' to distinguish betwee n intra- and intermonomeric NOEs. A comparison with the crystal struct ure and NMR analysis of the E. coli HU protein suggests that other hom ologous proteins in this family will possess similar tertiary structur es. This NMR strategy is applicable to the study of other proteins and their biomolecular complexes.