Structural highlights
Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedPlants and microorganisms reduce environmental inorganic nitrogen to ammonium, which then enters various metabolic pathways solely via conversion of 2-oxoglutarate (2OG) to glutamate and glutamine. Cellular 2OG concentrations increase during nitrogen starvation. We recently identified a family of 2OG-sensing proteins--the nitrogen regulatory protein NrpR--that bind DNA and repress transcription of nitrogen assimilation genes. We used X-ray crystallography to determine the structure of NrpR regulatory domain. We identified the NrpR 2OG-binding cleft and show that residues predicted to interact directly with 2OG are conserved among diverse classes of 2OG-binding proteins. We show that high levels of 2OG inhibit NrpRs ability to bind DNA. Electron microscopy analyses document that NrpR adopts different quaternary structures in its inhibited 2OG-bound state compared with its active apo state. Our results indicate that upon 2OG release, NrpR repositions its DNA-binding domains correctly for optimal interaction with DNA thereby enabling gene repression. Structural underpinnings of nitrogen regulation by the prototypical nitrogen-responsive transcriptional factor NrpR.,Wisedchaisri G, Dranow DM, Lie TJ, Bonanno JB, Patskovsky Y, Ozyurt SA, Sauder JM, Almo SC, Wasserman SR, Burley SK, Leigh JA, Gonen T Structure. 2010 Nov 10;18(11):1512-21. PMID:21070950[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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