Non-hydrolytic release of iron from ferrienterobactin analogs by extracts of bacillus subtilis

Abstract

The ferric chelates of the microbial siderophore enterobactin and of two synthetic analogs of enterobactin were sources of iron for growth of Bacillus subtilis WB2802. The ferrisiderophore reductase system in cell-free extracts of this organism catalyzed reductive removal of iron from the three ferric chelates. Reduced nicotinamide adenine dinucleotide phosphate was the reductant and flavin mononucleotide plus magnesium were required for maximum rates of reaction. Both of the enterobactin analogs lack the ester bonds found in enterobactin and one of the analogs should be insensitive to peptidases. Therefore, hydrolysis of ferrienterobactin may not be required for metabolic assimilation of iron from ferrienterobactin.