1uxd
From Proteopedia
Fructose repressor DNA-binding domain, NMR, 34 structures
Structural highlights
Function[CRA_ECOLI] Global transcriptional regulator, which plays an important role in the regulation of carbon metabolism. Activates transcription of genes encoding biosynthetic and oxidative enzymes (involved in Krebs cycle, glyoxylate shunt and gluconeogenesis, such as ppsA and fbp). Represses genes involved in sugar catabolism, such as fruB, pfkA, pykF and adhE. Binds asymmetrically to the two half-sites of its operator.[1] [2] [3] [4] [5] [6] [7] [8] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedFruR is an Escherichia coli transcriptional regulator that belongs to the LacI DNA-binding protein family. By using 1H and 15N NMR spectroscopy, we have determined the three-dimensional solution structure of the FruR N-terminal DNA-binding domain consisting of 57 amino acid residues. A total of 809 NMR-derived distances and 54 dihedral angle constraints have been used for molecular modelling with the X-PLOR program. The resulting set of calculated structures presents an average root-mean-square deviation of 0.37 A at the main-chain level for the first 47 residues. This highly defined N-terminal part of the structure reveals a similar topology for the three alpha-helices when compared to the 3D structures of LacI and PurR counterparts. The most striking difference lies in the connection between helix II and helix III, in which three additional residues are present in FruR. This connecting segment is well structured and contains a type III turn. Apart from hydrophobic interactions of non-polar residues with the core of the domain, this connecting segment is stabilised by several hydrogen bonds and by the aromatic ring stacking between Tyr19 of helix II and Tyr28 of the turn. The region containing the putative "hinge helix" (helix IV), that has been described in PurR-DNA complex to make specific base contacts in the minor groove of DNA, is unfolded. Examination of hydrogen bonds highlights the importance of homologous residues that seem to be conserved for their ability to fulfill helix N and C-capping roles in the LacI repressor family. Three-dimensional structure of the DNA-binding domain of the fructose repressor from Escherichia coli by 1H and 15N NMR.,Penin F, Geourjon C, Montserret R, Bockmann A, Lesage A, Yang YS, Bonod-Bidaud C, Cortay JC, Negre D, Cozzone AJ, Deleage G J Mol Biol. 1997 Jul 18;270(3):496-510. PMID:9237914[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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