NMR Structure of the DNA-Binding Domain of the Cell Cycle Protein Mbp1 from Saccharomyces cerevisiaeNair, M., McIntosh, P.B., Frenkiel, T.A., Kelly, G., Taylor, I.A., Smerdon, S.J., Lane, A.N.
(2003) Biochemistry 42: 1266-1273
- PubMed: 12564929
- DOI: 10.1021/bi0205247
- PubMed Abstract:
The three-dimensional solution structure of the DNA-binding domain of Mlu-1 box binding protein (Mbp1) has been determined by multidimensional NMR spectroscopy. Mbp1 is a cell cycle transcription factor from Saccharomyces cerevisiae and consists of a ...
The three-dimensional solution structure of the DNA-binding domain of Mlu-1 box binding protein (Mbp1) has been determined by multidimensional NMR spectroscopy. Mbp1 is a cell cycle transcription factor from Saccharomyces cerevisiae and consists of an N-terminal DNA-binding domain, a series of ankyrin repeats, and a heterodimerization domain at the C-terminus. A set of conformers comprising 19 refined structures was calculated via a molecular dynamics simulated annealing protocol using distance, dihedral angle, and residual dipolar coupling restraints derived from either double or triple resonance NMR experiments. The solution structure consists of a six-stranded beta-sheet segment folded against two pairs of alpha-helices in the topology of the winged helix-turn-helix family of proteins and is in agreement with the X-ray structures. In addition, the solution structure shows that the C-terminal tail region of this domain folds back and makes specific interactions with the N-terminal beta-strand of the protein. This C-terminal region is essential for full DNA-binding activity but appears in the X-ray structure to be disordered. The fold-back structure extends the region of positive electrostatic potential, and this may enhance the nonspecific contribution to binding by favorable electrostatic interactions with the DNA backbone.
Division of Molecular Structure, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, United Kingdom.