1B9M

REGULATOR FROM ESCHERICHIA COLI

Summary for 1B9M

• Entry DOI: 10.2210/pdb1b9m/pdb
• Descriptor: PROTEIN (MODE), NICKEL (II) ION (3 entities in total)
• Functional Keywords: dna-binding, gene regulation, winged helix turn helix, molybdate, ob fold, transcription
• Biological source: Escherichia coli
• Total number of polymer chains: 2
• Total formula weight: 57520.89

Authors

Hall, D.R.,Gourley, D.G.,Hunter, W.N. (deposition date: 1999-02-12, release date: 2000-03-15, Last modification date: 2023-12-27)

Primary citation

Hall, D.R.,Gourley, D.G.,Leonard, G.A.,Duke, E.M.,Anderson, L.A.,Boxer, D.H.,Hunter, W.N.
The high-resolution crystal structure of the molybdate-dependent transcriptional regulator (ModE) from Escherichia coli: a novel combination of domain folds.
EMBO J., 18:1435-1436, 1999

PubMed Abstract: 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.

PubMed: 10075916
DOI: 10.1093/emboj/18.6.1435

Experimental method

X-RAY DIFFRACTION (1.75 Å)