Petrobactin is the Primary Siderophore Synthesized by Bacillus anthracis Str. Sterne under Conditions of Iron Starvation

Abstract

The siderophores of Bacillus anthracis are critical for the pathogen's proliferation and may be necessary for its virulence. Bacillus anthracis str. Sterne cells were cultured in iron free media and the siderophores produced were isolated and purified using a combination of XAD-2 resin, reverse-phase FPLC, and size exclusion chromatography. A combination of 1H and 13C NMR spectroscopy, UV spectroscopy and ESI-MS/MS fragmentation were used to identify the primary siderophore as petrobactin, a catecholate species containing unusual 3,4-dihydroxybenzoate moieties, previously only identified in extracts of Marinobacter hydrocarbonoclasticus. A secondary siderophore was observed and structural analysis of this species is consistent with that reported for bacillibactin, a siderophore observed in many species of bacilli. This is the first structural characterization of a siderophore from B. anthracis, as well as the first characterization of a 3,4-DHB containing catecholate in a pathogen.

Genomic versatility and functional variation between two dominant heterotrophic symbionts of deep-sea Osedax worms

“…Likewise, siderophores, for which coding genes were identified in the Osedax symbiont Rs2 genome, can also effectively scavenge iron from host iron-binding compounds. Interestingly, the siderophore transport genes observed in the Rs2 symbiont were similar (45-55% by aminoacid content) to those encoding the citrate-containing siderophores petrobactin, anguibactin and vibriobactin found in many pathogenic bacteria (Griffiths et al, 1984;Actis et al, 1986;Koppisch et al, 2005). Iron scavenging has been shown to be critically important to successful virulence and may confer the same advantage for accessing iron in intracellular beneficial endosymbionts as it does Indicates a complete cassette, with no abbreviation given.…”

Functional and Structural Analysis of the Siderophore Synthetase AsbB through Reconstitution of the Petrobactin Biosynthetic Pathway from Bacillus anthracis

“…Conversely, a second siderophore, petrobactin (Fig. 1A), is essential for virulence within current infection models (6,10) and has since become a focus of multiple microbiological, genetic, and biochemical studies (3,(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)20). This mixed catechol-carboxylate siderophore was first isolated from the Gram-negative marine microbe Marinobacter hydrocarbonoclasticus (21).…”

“…This mixed catechol-carboxylate siderophore was first isolated from the Gram-negative marine microbe Marinobacter hydrocarbonoclasticus (21). Transcriptional analysis of B. anthracis mutants deficient for growth in iron-depleted conditions enabled identification of a pathway responsible for siderophore biosynthesis with enzymatic machinery encoded by the B. anthracis siderophore biosynthesis (asb) operon and a metabolite identical to the marine-derived siderophore petrobactin (6,7,22).…”

Characterization of a Bacillus subtilis transporter for petrobactin, an anthrax stealth siderophore

“…1) (13)(14)(15). PB is a crucial virulence component of B. anthracis that enables the bacteria to establish infection in mice and supports development in macrophages (16).…”