title: Reactions of nitric oxide and oxygen with the regulator of fumarate and nitrate reduction, a global transcriptional regulator, during anaerobic growth of Escherichia coli.
abstract: The Escherichia coli fumarate and nitrate reductase (FNR) regulator protein is an important transcriptional regulator that controls the expression of a large regulon of more than 100 genes in response to changes in oxygen availability. FNR is active when it acquires a [4Fe-4S](2+) cluster under anaerobic conditions. The presence of the [4Fe-4S](2+) cluster promotes protein dimerization and site-specific DNA binding, facilitating activation or repression of target promoters. Oxygen is sensed by the controlled disassembly of the [4Fe-4S](2+) cluster, ultimately resulting in inactive, monomeric, apo-FNR. The FNR [4Fe-4S](2+) cluster is also sensitive to nitric oxide, such that under anaerobic conditions the protein is inactivated by nitrosylation of the iron-sulfur cluster, yielding a mixture of monomeric and dimeric dinitrosyl-iron cysteine species. This chapter describes some of the methods used to produce active [4Fe-4S] FNR protein and investigates the reaction of the [4Fe-4S](2+) cluster with nitric oxide and oxygen in vitro.
authors.affiliation: Centre for Metalloprotein Spectroscopy and Biology, School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich, United Kingdom.
authors.forename: Jason C
authors.initials: JC
authors.lastname: Crack
authors.forename: Nick E
authors.initials: NE
authors.lastname: Le Brun
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Thomson
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Green
authors.forename: Adrian J
authors.initials: AJ
authors.lastname: Jervis
mesh_terms: D000143:Acids / Q000494:pharmacology; D000693:Anaerobiosis / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000502:physiology; D005650:Fumarates / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D007501:Iron / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000502:physiology; D009566:Nitrates / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism*; D010545:Peroxides / Q000032:analysis; D011994:Recombinant Proteins / Q000302:isolation & purification; D013056:Spectrophotometry, Ultraviolet; D013440:Sulfides / Q000378:metabolism; D013481:Superoxides / Q000032:analysis; D014158:Transcription, Genetic
chemical_list: D000143:Acids; D029968:Escherichia coli Proteins; C060704:FNR protein, E coli; D005650:Fumarates; D007506:Iron-Sulfur Proteins; D009566:Nitrates; D010545:Peroxides; D011994:Recombinant Proteins; D013440:Sulfides; D013481:Superoxides; C066317:ferryl iron; D009569:Nitric Oxide; D007501:Iron; D010100:Oxygen