1b9n
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REGULATOR FROM ESCHERICHIA COLI
OverviewOverview
The molybdate-dependent transcriptional regulator (ModE) from Escherichia coli functions as a sensor of molybdate concentration and a regulator for transcription of operons involved in the uptake and utilization of the essential element, molybdenum. We have determined the structure of ModE using multi-wavelength anomalous dispersion. Selenomethionyl and native ModE models are refined to 1. 75 and 2.1 A, respectively and describe the architecture and structural detail of a complete transcriptional regulator. ModE is a homodimer and each subunit comprises N- and C-terminal domains. The N-terminal domain carries a winged helix-turn-helix motif for binding to DNA and is primarily responsible for ModE dimerization. The C-terminal domain contains the molybdate-binding site and residues implicated in binding the oxyanion are identified. This domain is divided into sub-domains a and b which have similar folds, although the organization of secondary structure elements varies. The sub-domain fold is related to the oligomer binding-fold and similar to that of the subunits of several toxins which are involved in extensive protein-protein interactions. This suggests a role for the C-terminal domain in the formation of the ModE-protein-DNA complexes necessary to regulate transcription. Modelling of ModE interacting with DNA suggests that a large distortion of DNA is not necessary for complex formation.
About this StructureAbout this Structure
1B9N is a Single protein structure of sequence from Escherichia coli with as ligand. Full crystallographic information is available from OCA.
ReferenceReference
The high-resolution crystal structure of the molybdate-dependent transcriptional regulator (ModE) from Escherichia coli: a novel combination of domain folds., Hall DR, Gourley DG, Leonard GA, Duke EM, Anderson LA, Boxer DH, Hunter WN, EMBO J. 1999 Mar 15;18(6):1435-46. PMID:10075916
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