1h9s
From Proteopedia
Molybdate bound complex of Dimop domain of ModE from E.coli
Structural highlights
Function[MODE_ECOLI] The ModE-Mo complex acts as a repressor of the modABC operon, involved in the transport of molybdate. Upon binding molybdate, the conformation of the protein changes, promoting dimerization of ModE-Mo. The protein dimer is then competent to bind a DNA region, upstream of the modABC operon, which contains an 8-base inverted repeat 5'-TAACGTTA-3' flanked by two CAT boxes. Acts also as an enhancer of the expression of genes coding for molybdoenzymes, both directly and indirectly. ModE also interacts with tungstate. 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 PubMedThe molybdate-dependent transcriptional regulator ModE of Escherichia coli functions as a sensor of intracellular molybdate concentration and a regulator for the transcription of several operons that control the uptake and utilization of molybdenum. We present two high-resolution crystal structures of the C-terminal oxyanion-binding domain in complex with molybdate and tungstate. The ligands bind between subunits at the dimerization interface, and analysis reveals that oxyanion selectivity is determined primarily by size. The relevance of the structures is indicated by fluorescence measurements, which show that the oxyanion binding properties of the C-terminal domain of ModE are similar to those of the full-length protein. Comparisons with the apoprotein structure have identified structural rearrangements that occur on binding oxyanion. This molybdate-dependent conformational switch promotes a change in shape and alterations to the surface of the protein and may provide the signal for recruitment of other proteins to construct the machinery for transcription. Sequence and structure-based comparisons lead to a classification of molybdate-binding proteins. Oxyanion binding alters conformation and quaternary structure of the c-terminal domain of the transcriptional regulator mode. Implications for molybdate-dependent regulation, signaling, storage, and transport.,Gourley DG, Schuttelkopf AW, Anderson LA, Price NC, Boxer DH, Hunter WN J Biol Chem. 2001 Jun 8;276(23):20641-7. Epub 2001 Mar 20. PMID:11259434[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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