A siderophore from a marine bacterium with an exceptional ferric ion affinity constant
| Autor: | Richard T. Reid, Alison Butler, D H Live, D J Faulkner |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Models
Molecular Siderophore Magnetic Resonance Spectroscopy Protein Conformation Microorganism Molecular Sequence Data Siderophores Biology Spectrometry Mass Fast Atom Bombardment Ferric Compounds Peptides Cyclic Ferric ion Phytoplankton medicine Amino Acid Sequence Alteromonas Multidisciplinary Gram-Negative Aerobic Bacteria Ecology Affinity constant biology.organism_classification Environmental chemistry Ferric Oligopeptides Bacteria medicine.drug |
| Zdroj: | Nature. 366(6454) |
| ISSN: | 0028-0836 |
| Popis: | Virtually all microorganisms require iron for growth. The paucity of iron in surface ocean water (approximately 0.02-1.0 nM (refs 1, 2)) has spurred a lively debate concerning iron limitation of primary productivity, yet little is known about the molecular mechanisms used by marine microorganisms to sequester iron. Terrestrial bacteria use a siderophore-mediated ferric uptake system. A siderophore is a low-molecular-mass compound with a high affinity for ferric ion which is secreted by microorganisms is response to low-iron environments; siderophore biosynthesis is regulated by iron levels, with repression by high iron. Although open-ocean marine microorganisms (such as phytoplankton and bacteria) produce siderophores, the nature of these siderophores has not been investigated. We report here the first structure determination, to our knowledge, of the siderophores from an open-ocean bacterium, alterobactin A and B from Alteromonas luteoviolacea. A. luteoviolacea is found in oligotrophic and coastal waters. Alterobactin A has an exceptionally high affinity constant for ferric ion. We suggest that at least some marine microorganisms may have developed higher-affinity iron chelators as part of an efficient iron-uptake mechanism which is more effective than that of their terrestrial counterparts. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|