2hzv
From Proteopedia
NikR-operator DNA complex
Structural highlights
FunctionNIKR_ECOLI Transcriptional repressor of the nikABCDE operon. Is active in the presence of excessive concentrations of intracellular nickel.[HAMAP-Rule:MF_00476] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedMetal 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. References
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