@article {46401,
	title = {NikR-operator complex structure and the mechanism of repressor activation by metal ions.},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {103},
	year = {2006},
	month = {2006 Sep 12},
	pages = {13676-81},
	abstract = {<p>Metal ion homeostasis is critical to the survival of all cells. Regulation of nickel concentrations in Escherichia coli is mediated by the NikR repressor via nickel-induced transcriptional repression of the nickel ABC-type transporter, NikABCDE. Here, we report two crystal structures of nickel-activated E. coli NikR, the isolated repressor at 2.1 A resolution and in a complex with its operator DNA sequence from the nik promoter at 3.1 A resolution. Along with the previously published structure of apo-NikR, these structures allow us to evaluate functional proposals for how metal ions activate NikR, delineate the drastic conformational changes required for operator recognition, and describe the formation of a second metal-binding site in the presence of DNA. They also provide a rare set of structural views of a ligand-responsive transcription factor in the unbound, ligand-induced, and DNA-bound states, establishing a model system for the study of ligand-mediated effects on transcription factor function.</p>
},
	keywords = {Amino Acid Sequence, Base Sequence, Binding Sites, Crystallography, Escherichia coli Proteins, Molecular Sequence Data, Nickel, Operator Regions, Genetic, Protein Conformation, Repressor Proteins},
	issn = {0027-8424},
	doi = {10.1073/pnas.0606247103},
	author = {Schreiter, Eric R and Wang, Sheila C and Zamble, Deborah B and Drennan, Catherine L}
}
