Ferric uptake regulation protein

TF transcription factor, R receptor, Fur ferric uptake regulation protein, NF-kB nuclear factor-kB, AP-1 activator protein-1, Egr-1 early growth response-1, VDR la,25-dihydroxy-vitamin D3 receptor, RXR retinoid X receptor, PPARy peroxisome proliferator-activated receptor y NFAT nuclear factor of activated T-cells, HSF heat shock factor, p53 tumor suppressor p53, HIF-1 hypoxia inducible factor-1. ... 

Once the siderophore-iron complexes are inside the bacteria, the iron is released and utilized for vital cell functions. The iron-free hydroxamate siderophores are commonly re-excreted to bring in an additional iron load (Enterobactin is at least partially degraded by a cytoplasmic esterase This cycle is repeated until specific intracellular ferric uptake regulation proteins (Fur proteins) bind iron, and signal that the intracellular iron level is satisfactory, at -which point ne-w siderophore and siderophore-receptor biosynthesis are halted and the iron-uptake process stops. This intricate feedback mechanism allows a meticulous control over iron(III) uptake and accumulation against an unfavorable concentration gradient so as to maintain the intracellular iron(III) level within the required narrow window. Several excellent reviews concerning siderophore-iron transport mechanisms have been recently published i.3,i6, is,40,45,60-62 ... 

The Fur (Ferric uptake regulation) protein is a negative regulator of the aerobactin-operon and of several other siderophore-mediated, high affinity iron transport systems in... 

Gonzalez de Peredo, A. Saint-Pierre, C. Latour, J. M. Michaud-Soret, 1. Forest, E. Conformational changes of the ferric uptake regulation protein upon metal activation and DNA binding First evidence of structural homologies with the diphtheria toxin repressor. J. Mol Biol 2001, 3/0(1), 83-91. 

Pohl, E., Haller, J.C., Mijovilovich, A., Meyer-Klauke, W., Garman, E. and Vasil, M.L. (2003) Architecture of a protein central to iron homeostasis crystal structure and spectroscopic analysis of the ferric uptake regulator, Molec. Microbiol., 47, 903-915. 

As is pointed out in Chapter 16, the acquisition of iron and control of its concentration is of crucial importance to bacteria. In E. coli the Fe2+-binding protein Fur (ferric uptake regulator) represses promoters controlling siderophore biosynthesis as well as other responses. It is a global regulator that controls 40 transcriptional units.124 Similar proteins repress synthesis of the diphtheria toxin by Corynebac-terium diphtheriae,125 126 uptake of iron in these bacteria and in Mycobacterium tuberculosis,127 and uptake of molybdate.1273... 

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