The cytoplasmic fractions obtained from Bacillus subtilis strains W168 and WB2802 catalyzed reductive release of iron from the ferric chelate of 2,3-dihydroxybenzoic acid (ferri-DHB), the ferrisiderophore produced by B. subtilis. Ferrisiderophore reductase activity may insert iron into metabolism. This activity required a reductant (reduced nicotinamide adenine dinucleotide phosphate was preferred), was oxygen sensitive, and was stimulated by flavin mononucleotide plus certain divalent cations. The cytoplasmic fractions also reduced 2,6-dichlorophenolindophenol; this reaction was stimulated by flavin mononucleotide plus a divalent cation. Ferri-DHB and 2,6-dichlorophenolindophenol reductase activities were copurified by phosphocellulose and diethylaminoethyl-cellulose chromatography. Nondenaturing polyacrylamide gel electrophoresis of the purified material revealed that both ferri-DHB and 2,6-dichlorophenolindophenol reductase activities were located in a protein band at Rf 0.75. The chromatographic procedures purified a reductase known to be associated with two aromatic biosynthetic enzymes, chorismate synthase and dehydroquinate synthase. Therefore, a portion of the ferrisiderophore reductase activity in B. subtilis may be catalyzed by a reductase that also is essential for aromatic biosynthesis.

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Article may be found at: http://jb.asm.org/cgi/reprint/148/2/527 This research was supported by Public Health Service grant GM 23778 from the National Institute of General Medical Sciences.ISSN:1098-5530 Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works in February 2014.

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Department, Program, or Center

Thomas H. Gosnell School of Life Sciences (COS)


RIT – Main Campus