Download MendeleyThe X-ray structure of the DNA-binding domain from the Saccharomyces cerevisiae cell-cycle transcription factor Mbp1 at 2.1 A resolution.
Taylor, I.A., Treiber, M.K., Olivi, L., Smerdon, S.J.(1997) J Mol Biol 272: 1-8
- PubMed: 9299332
- DOI: https://doi.org/10.1006/jmbi.1997.1229
- Primary Citation of Related Structures:
1MB1 - PubMed Abstract:
The structure of the DNA-binding domain of the Saccharomyces cerevisiae cell-cycle transcription factor Mbp1 has been solved using the multiwavelength anomalous diffraction (MAD) technique on crystals of selenomethionyl protein and refined at 2.1 A resolution. The molecule is globular, consisting of a twisted, six-stranded beta-barrel that is packed against a loose bundle of four alpha-helices. Two of the beta-strands in combination with two of the helices form a structure characteristic of the DNA-binding motif found in the CAP family of helix-turn-helix transcription factors. In Mbp1, this beta2/alpha2 motif is associated with regions of both positive electrostatic potential and sequence conservation within the Mbp1/Swi4 family, suggesting a role in DNA-binding in these proteins. A combination of structural and biochemical data further indicate a similarity to HNF3gamma/fork head, a member of the family of "winged" helix-turn-helix proteins. We propose a model for DNA-binding involving a recognition helix in the major groove, phosphodiester backbone interactions through the beta-hairpin and further base and/or phosphate interactions mediated by a C-terminal, positively charged loop.
Organizational Affiliation:
Division of Protein Structure, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, U.K.
