TonB-dependent receptors in gram-negative bacteria are associated with the uptake and transport of large substrates such as iron siderophore complexes and vitamin B12. (wikipedia.org)
During iron sufficiency, SreA represses iron uptake, including reductive iron assimilation and siderophore-mediated iron uptake, to avoid toxic effects. (frontiersin.org)
This study shows the natural occurrence of serratiochelins, photobactin, enterobactin, and aerobactin in a single bacterial species and illuminates the interplay between siderophore biosynthetic pathways and polyamine production, indicating routes of molecular diversification. (biomedcentral.com)
Some bacteria have evolved extraordinary ways to synthesize proprietary siderophores that require the expression of specialized TonB-dependent receptors (TBDRs) to allow for efficient siderophore uptake by the producer and its relatives [ 15 ]. (biomedcentral.com)
High-affinity1
In Escherichia coli, the TonB protein interacts with outer membrane receptor proteins that carry out high-affinity binding and energy-dependent uptake of specific substrates into the periplasmic space. (wikipedia.org)
Soluble3
Ferric pyrophosphate citrate (FPC) is a novel, water-soluble complex iron salt. (bvsalud.org)
Despite its high abundance in the Earth's crust, the bioavailability of iron is low owing to its oxidation into sparingly soluble ferric (Fe 3+ ) hydroxides by atmospheric oxygen. (frontiersin.org)
Siderophores chelate Fe 3+ for uptake into the cell, where it is reduced to soluble Fe 2+ . (biomedcentral.com)
Siderophores2
Therefore, fungi evolved fine-tuned mechanisms for uptake and storage of iron, such as the production of siderophores (low-molecular mass iron-specific chelators). (frontiersin.org)
Mutant strains not synthesizing polyamine-siderophores significantly increased enterobactin production levels, though lack of enterobactin did not impact the production of serratiochelins. (biomedcentral.com)
Bacterial1
Knocking out SchF0, an enzyme involved in the assembly of enterobactin alone, significantly reduced bacterial fitness. (biomedcentral.com)
Iron2
Subtle differences are detected between two forms of FepA, ligand-free and complexed with its natural iron carrier, the enterobactin. (nature.com)
These complexes deliver iron in a usable form to the body while avoiding the serious adverse effects of un-complexed forms of iron, such as polynuclear ferric oxyhydroxide. (bvsalud.org)
Transporter1
The complex of ferric-enterobactin with its transporter from Pseudomonas aeruginosa suggests a two-site model. (ox.ac.uk)
Specific2
In Escherichia coli, the TonB protein interacts with outer membrane receptor proteins that carry out high-affinity binding and energy-dependent uptake of specific substrates into the periplasmic space. (wikipedia.org)
In specific, enterobactin may be modified into salmochelins by the addition of as much as three glucose molecules on its catechol moieties (Hantke et al. (tradebenefitsamerica.org)