Structure of putrebactin, a new dihydroxamate siderophore produced by Shewanella putrefaciens

Magnetic susceptibility of Mn(III) complexes of hydroxamate siderophores

“…Efforts to increase the extent of Mn(II) oxidation in the putrebactin reactions at elevated pH was hampered by precipitation above pH 9.5, which differs from the stability of Mn(III)-DFOB and Mn(III)-DFOE up to pH 11.1. The second pK a of putrebactin at 9.71 [26] is higher than the stable solution pH for the Mn(II/III)-putrebactin complexes, which may contribute to the lack of formation and stabilization of Mn(III)-putrebactin complexes, since the Mn(III) oxidation state is stabilized by complexation to hard anionic ligands. respectively [25].…”

“…Comparison of the tris-hydroxamate to bis-hydroxamate siderophores is of particular interest due to differences expected in the stoichiometry of coordination, analogous to the Fe(III)-siderophore complexes [24][25][26][27]. Possible coordination complexes of Mn(III) and putrebactin could include the neutral bridged 2:3 Mn-putrebactin or 1:2 Mn-putrebactin complexes shown in Figure 2 Prior to inoculation, 20 mL of filter-sterilized 1.0 M HEPES buffer (pH 7.4), and 4 mL of filtersterilized 1.0 M NaHCO 3 buffer were added to the medium.…”

Siderophores Are Not Involved in Fe(III) Solubilization during Anaerobic Fe(III) Respiration by Shewanella oneidensis MR-1

“…Hydroxamate-type siderophores are produced via N 6 hydroxylation and N 6 acylation of L-ornithine and, in some cases, cyclization to macrocyclic ring structures (13). The macrocyclic siderophores bisucaberin and putrebactin, for example, are two structural analogs of the cyclic bis(hydroxamate) siderophore alcaligin, synthesized by Aliivibrio salmonicida and Shewanella putrefaciens strain 200, respectively (27,32,65). After transport across the cell envelope via a TonB-dependent pathway, Fe(III) is subsequently released from the Fe(III)-siderophore complex by ligand exchange reactions promoted by siderophore ligand hydrolysis and/or protonation or by Fe(III)-siderophore reduction and release of Fe(II) to acceptor ligands (9,66).…”

Erythrochelin – a hydroxamate‐type siderophore predicted from the genome of Saccharopolyspora erythraea

“…The second class is known as NRPS-independent siderophores and involves a novel family of synthetases, represented by IucA and IucC, which are responsible for aerobactin (E. coli K-12) biosynthesis [9,10]. Siderophores of NRPS-independent origin encompass desferrioxamine E (Streptomyces coelicolor M145), putrebactin (Shewanella putrefaciens) and further compounds [11,12]. The biosynthetic genes of these secondary metabolites are usually clustered within one operon, showing coordinated transcriptional regulation [13].…”