Structural dynamics and functional domains of the Fur protein

Abstract

Proteolytic enzymes were used to detect metal-induced conformational changes in the ferric uptake regulation (Fur) protein of Escherichia coli K12. Metal binding results in enhanced cleavage of the N-terminal region of Fur by trypsin and chymotrypsin. Activation of both trypsinolysis sensitivity and DNA binding have similar metal ion specificity and concentration dependencies, suggesting that the conformational change detected is required for operator DNA binding. Isolation and characterization of biochemically generated fragments of Fur as well as other data indicate that the N-terminal region is necessary for the interaction of the repressor with DNA and that a C-terminal domain is sufficient for binding to metal ions.

Biochemical Characterization of the Structural Zn2+ Site in the Bacillus subtilis Peroxide Sensor PerR

“…In contrast, B. subtilis PerR has been shown recently to detect low levels (Ͻ100 M) of H 2 O 2 by iron-catalyzed oxidation of either of two His residues, His 37 and His 91 (9 (16). However, analysis of E. coli Fur by amino-terminal sequencing and by electrospray ionization MS revealed that the fast migrating band is a proteolytic product of intact protein lacking the amino-terminal nine amino acids (28,29). Recently it has been noted that Zn 2ϩ binding is required for stable folding of the carboxyl-terminal domain of E. coli Fur and for protein dimerization (30).…”

Characterization of the Interaction between Fur and the Iron Transport Promoter of the Virulence Plasmid in Vibrio anguillarum

“…7 12). Although there was no helix-turn-helix DNA binding motif found, it has been suggested that ␣-helices in the N-terminal region of E. coli Fur may interact with the major groove of the DNA upon sequence-specific recognition (30,31). However, it is difficult to employ the binding mode of E. coli Fur for the V. anguillarum Fur, since the sequence-specific protein-DNA interactions through the major groove generally require a high conservation of DNA sequence, but the DNA sequences involved in the binding to V. anguillarum Fur show a high diversity without any pattern.…”

A Novel DNA-binding Site for the Ferric Uptake Regulator (Fur) Protein from Bradyrhizobium japonicum

“…Fur proteins are likely to be dimeric in solution (10,11), and the P. aeruginosa protein was crystallized as a dimer (9). A model for Fur based on the crystal structure of the unbound protein depicts two dimers binding to target DNA.…”

“…Structural analysis of Fur and its DNA binding properties has been most extensively studied in Escherichia coli, Pseudomonas aeruginosa, and Bacillus subtilis, whereas analyses of fur mutants and the identification of genes under Fur control have also been studied in those bacteria and in several other organisms as well. P. aeruginosa Fur was crystallized as a dimer (9), which also appears to be its oligomerization state in solution (10,11). It has been proposed that at least two Fur dimers occupy its target promoter based on the size of protected DNA in footprinting analyses (12).…”