Publication Abstract from PubMed
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.
NMR structure of the DNA-binding domain of the cell cycle protein Mbp1 from Saccharomyces cerevisiae.,Nair M, McIntosh PB, Frenkiel TA, Kelly G, Taylor IA, Smerdon SJ, Lane AN Biochemistry. 2003 Feb 11;42(5):1266-73. PMID:12564929[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
