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Publication Abstract from PubMed

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.

NikR-operator complex structure and the mechanism of repressor activation by metal ions.,Schreiter ER, Wang SC, Zamble DB, Drennan CL Proc Natl Acad Sci U S A. 2006 Sep 12;103(37):13676-81. Epub 2006 Aug 31. PMID:16945905^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.