Microbial Iron Transport Research Articles

Structure of pseudobactin A, a second siderophore from plant growth promoting Pseudomonas B10.

The structure of nonfluorescent pseudobactin A, one of two extracellular siderophores (microbial iron transport agents) produced by the plant growth promoting bacterium Pseudomonas B10, was determined by comparison of its 1H and 13C NMR spectra with those of yellow-green, fluorescent pseudobactin, the other siderophore. The molecular and crystal structure of ferric pseudobactin is reported in the preceding paper in this issue [Teintze, M., Hossain, M. B., Barnes, C. L., Leong J., & van der Helm, D. (1981) Biochemistry (preceding paper in this issue)]. The only structural difference between pseudobactin and pseudobactin A was that the latter was saturated at carbons 3 and 4 of the quinoline derivative, whereas pseudobactin is unsaturated at these positions. A mechanism is proposed for the observed conversion of pseudobactin A into pseudobactin in aqueous solution.

Enhanced plant growth by siderophores produced by plant growth-promoting rhizobacteria

Specific strains of the Pseudomonas fluorescens-putida group have recently been used as seed inoculants on crop plants to promote growth and increase yields. These pseudomonads, termed plant growth-promoting rhizobacteria (PGPR), rapidly colonize plant roots of potato, sugar beet and radish, and cause statistically significant yield increases up to 144% in field tests1–5. These results prompted us to investigate the mechanism by which plant growth was enhanced. A previous study indicated that PGPR increase plant growth by antagonism to potentially deleterious rhizoplane fungi and bacteria, but the nature of this antagonism was not determined6. We now present evidence that PGPR exert their plant growth-promoting activity by depriving native microflora of iron. PGPR produce extracellular siderophores (microbial iron transport agents)7 which efficiently complex environmental iron, making it less available to certain native microflora.

Coordination chemistry of microbial iron transport compounds. 20. Crystal and molecular structures of two salts of cis- and trans-tris(benzohydroximato)chromate(III)

Coordination chemistry of microbial iron transport compounds. 20. Crystal and molecular structures of two salts of cis- and trans-tris(benzohydroximato)chromate(III)

Ferrisiderophore reductase activity in Bacillus megaterium.

The release of iron from ferrisiderophores (microbial ferric-chelating iron transport cofactors) by cell-free extracts of Bacillus megaterium was demonstrated. Reductive transfer of iron from ferrisiderophores to the ferrous-chelating agent ferrozine was measured spectrophotometrically. This ferrisiderophore reductase activity (reduced nicotinamide adenine dinucleotide phosphate:ferrisiderophore oxidoreductase) was associated primarily with the cell soluble rather than particulate (membrane) fraction. Ferrisiderophore reductase was inhibited by oxygen and required the addition of a reductant (reduced nicotinamide adenine dinucleotide phosphate was most effective) for maximal activity. The activity was destroyed by both heat and protease treatments and was inhibited by iodoacetamide treatment. Ferrisiderophore reductase activity for several microbial ferrisiderophores was measured; highest activity was displayed for ferrischizokinen, the ferrisiderophore produced by this organism. The Km and Vmax values of the reductase for ferrischizokinen were 2.5 x 10(-4) M and 35.7 nmol/min per mg of the ferrisiderophore reductase reaction. Preliminary fractionation of the cell soluble material by gel filtration chromatography resulted in the demonstration of ferrisiderophore reductase activity in three peaks of different molecular weight. Ferrisiderophore reductase probably mediates entrance of iron into cellular metabolism.

Coordination chemistry of microbial iron transport compounds. 17. Preparation and structural characterization of tris(N-methylthiobenzohydroxamato)cobalt(III), -chromium(III), -iron(III), and -manganese(III)

Coordination chemistry of microbial iron transport compounds. 17. Preparation and structural characterization of tris(N-methylthiobenzohydroxamato)cobalt(III), -chromium(III), -iron(III), and -manganese(III)

Coordination chemistry of microbial iron transport compounds. 19. Stability constants and electrochemical behavior of ferric enterobactin and model complexes

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCoordination chemistry of microbial iron transport compounds. 19. Stability constants and electrochemical behavior of ferric enterobactin and model complexesWesley R. Harris, Carl J. Carrano, Stephen R. Cooper, Stephen R. Sofen, Alex E. Avdeef, James V. McArdle, and Kenneth N. RaymondCite this: J. Am. Chem. Soc. 1979, 101, 20, 6097–6104Publication Date (Print):September 1, 1979Publication History Published online1 May 2002Published inissue 1 September 1979https://doi.org/10.1021/ja00514a037RIGHTS & PERMISSIONSArticle Views1750Altmetric-Citations228LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (973 KB) Get e-Alerts Get e-Alerts

Coordination chemistry and microbial iron transport

ADVERTISEMENT RETURN TO ISSUEPREVArticleCoordination chemistry and microbial iron transportKenneth N. Raymond and Carl J. CarranoCite this: Acc. Chem. Res. 1979, 12, 5, 183–190Publication Date (Print):May 1, 1979Publication History Published online1 May 2002Published inissue 1 May 1979https://doi.org/10.1021/ar50137a004RIGHTS & PERMISSIONSArticle Views1219Altmetric-Citations265LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1016 KB) Get e-Alerts Get e-Alerts

Coordination chemistry of microbial iron transport compounds. 16. Isolation, characterization, and formation constants of ferric aerobactin

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCoordination chemistry of microbial iron transport compounds. 16. Isolation, characterization, and formation constants of ferric aerobactinWesley R. Harris, Carl J. Carrano, and Kenneth N. RaymondCite this: J. Am. Chem. Soc. 1979, 101, 10, 2722–2727Publication Date (Print):May 1, 1979Publication History Published online1 May 2002Published inissue 1 May 1979https://doi.org/10.1021/ja00504a038RIGHTS & PERMISSIONSArticle Views694Altmetric-Citations130LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (758 KB) Get e-Alerts Get e-Alerts

ChemInform Abstract: COORDINATION CHEMISTRY OF MICROBIAL IRON TRANSPORT COMPOUNDS. 14. ISOLATION AND STRUCTURAL CHARACTERIZATION OF TRANS‐TRIS(BENZOHYDROXAMATO)CHROMIUM(III)‐2‐(2‐PROPANOL)

Chemischer InformationsdienstVolume 10, Issue 15 Physical Organic Chemistry ChemInform Abstract: COORDINATION CHEMISTRY OF MICROBIAL IRON TRANSPORT COMPOUNDS. 14. ISOLATION AND STRUCTURAL CHARACTERIZATION OF TRANS-TRIS(BENZOHYDROXAMATO)CHROMIUM(III)-2-(2-PROPANOL) K. ABU-DARI, K. ABU-DARISearch for more papers by this authorJ. D. EKSTRAND, J. D. EKSTRANDSearch for more papers by this authorD. P. FREYBERG, D. P. FREYBERGSearch for more papers by this authorK. N. RAYMOND, K. N. RAYMONDSearch for more papers by this author K. ABU-DARI, K. ABU-DARISearch for more papers by this authorJ. D. EKSTRAND, J. D. EKSTRANDSearch for more papers by this authorD. P. FREYBERG, D. P. FREYBERGSearch for more papers by this authorK. N. RAYMOND, K. N. RAYMONDSearch for more papers by this author First published: April 10, 1979 https://doi.org/10.1002/chin.197915070Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume10, Issue15April 10, 1979 RelatedInformation

Agrobactin, a siderophore from Agrobacterium tumefaciens.

A siderophore (microbial iron transport compound) was isolated from low iron cultures of Agrobacterium tumefaciens B6. The substance was characterized as a threonyl peptide of spermidine acylated with 3 residues of 2,3-dihydroxybenzoic acid, the carbonyl group of 1 residue of the latter participating in an oxazoline ring with the beta-hydroxyl of the threonine moiety. The compound, N-[3-(2,3-dihydroxybenzamido)propyl]-N-[4-(2,3-dihydroxybenzamido)butyl]-2-(2,3-dihydroxyphenyl)-trans-5-methyl-oxazoline-4-carboxamide, was given the trivial name agrobactin. Exposure to acid opened the oxazoline ring to afford agrobactin A. Ferric agrobactin A and agrobactin A itself, but not agrobactin or its ferric complex, had some capacity to feed iron to enterobactin-deficient strains of Escherichia coli and Salmonella typhimurium. Agrobactin was produced by A. tumefaciens in response to iron deficiency and was able to reverse the iron starvation in this organism precipitated by the presence of a ferric complexing agent not utilized by the cells.

Coordination chemistry of microbial iron transport compounds. 14. Isolation and structural characterization of trans-tris(benzohydroxamato)chromium(III)-2-(2-propanol)

Coordination chemistry of microbial iron transport compounds. 14. Isolation and structural characterization of trans-tris(benzohydroxamato)chromium(III)-2-(2-propanol)

Coordination chemistry of microbial iron transport compounds. 11. Solution equilibriums and electrochemistry of ferric rhodotorulate complexes

Coordination chemistry of microbial iron transport compounds. 11. Solution equilibriums and electrochemistry of ferric rhodotorulate complexes

Coordination chemistry of microbial iron transport compounds. 15. Electrochemistry and magnetic susceptibility of iron(III)-hydroxamate and -thiohydroxamate complexes

Coordination chemistry of microbial iron transport compounds. 15. Electrochemistry and magnetic susceptibility of iron(III)-hydroxamate and -thiohydroxamate complexes

Coordination chemistry of microbial iron transport compounds. 13. Preparation and chirality of the rhodium(III) enterobactin complex and model tris(catecholato)rhodate(III) analogs

Coordination chemistry of microbial iron transport compounds. 13. Preparation and chirality of the rhodium(III) enterobactin complex and model tris(catecholato)rhodate(III) analogs

Coordination chemistry of microbial iron transport compounds: rhodotorulic acid and iron uptake in Rhodotorula pilimanae.

The mechanism by which iron uptake is facilitated by the siderophore rhodotorulic acid (RA) in the yeast Rhodotorula pilimanae was investigated with radioactively labeled Fe and RA and kinetically inert, chromic-substituted RA complexes. The weight of the evidence supports a model in which RA mediates iron transport to the cell but does not actually transport iron into the cell. It is proposed that RA exchanges the ferric ion at the cell surface with a membrane-bound chelating agent that completes the active transport of iron into the cell. Uptake of 55Fe in ferric rhodotorulate was much more rapid than uptake of RA itself. Two exchange-inert chromic complexes of RA showed no uptake.

Coordination chemistry of microbial iron transport compounds. 10. Characterization of the complexes of rhodotorulic acid, a dihydroxamate siderophore

Coordination chemistry of microbial iron transport compounds. 10. Characterization of the complexes of rhodotorulic acid, a dihydroxamate siderophore

Coordination chemistry of microbial iron transport compounds. 9. Stability constants for catechol models of enterobactin

The stability constants of ferric complexes with several substituted catechol (1,2-dihydroxybenzene) ligands in aqueous solutions of low ionic strength have been determined at 27/sup 0/C in the pH range 2 to 11. Enterobactin, the principal siderophore of enteric bacteria, is a tricatechol and, from the formation constants reported here, is estimated to have a formation constant with ferric ion which is greater than 10/sup 45/. The stepwise formation constants, K/sub n/, of the catechol ligands reported here are defined as (ML/sub n/)/(ML/sub n-1/)(L), in units of L mol/sup -1/, where (L) is the concentration of the deprotonated catechol ligand. The constants were determined from potentiometric and spectroscopic data and were refined on pH values by weighted least squares. Qualitative examination of electron spin resonance spectra of the systems indicated some oxidation of the ligand by ferric ions at pH values as high as 4. The ligands studied included catechol (cat) (log K/sub 1/ = 20.01, log K/sub 2/ = 14.69, log K/sub 3/ = 9.01); 4,5-dihydroxy-m-benzenedisulfonate (Tiron) (log K/sub 2/ = 15.12, log K/sub 3/ = 10.10); 4-nitrocatechol (ncat) (log K/sub 1/ = 17.08, log K/sub 2/ = 13.43, log K/sub 3/ = 9.51); 3,4-dihydroxyphenylacetic acid (dhpa) (log K/sub 1/more » = 20.1, log K/sub 2/ = 14.9, log K/sub 3/ = 9.0); and 2,3-dihydroxybenzoic acid (dhba) (log K/sub 1/ = 20.5). The acid dissociation constants, K/sub a/s, were determined also. For the catechol protons these follow: cat (pK/sub a/sub 1// = 9.22, pK/sub a/sub 2// = 13.0); Tiron (pK/sub a/sub 1// = 7.70, pK/sub a/sub 2// = 12.63); ncat (pK/sub a/sub 1// = 6.65, pK/sub a/sub 2// = 10.80); dhpa (pK/sub a/sub 1// = 9.49, pK/sub a/sub 2// = 13.7); and dhba (pK/sub a/sub 1// = 10.06, pK/sub a/sub 2// = 13.1). In addition, carboxylate substituents of dhpa and dhba have pK/sub a/s of 4.17 and 2.70, respectively.In solution, exchange is slow between these two types of coordination following changes in pH. 2 tables, 11 figures, 52 references.« less

Iron transport in Mycobacterium smegmatis: Ferrimycobactin reductase (NAD(P)H:Ferrimycobactin oxidoreductase), the enzyme releasing iron from its carrier

Mycobactin is a lipid-soluble iron-binding compound, which is located in the mycobacterial cell envelope where it acts as a transporter of ferric ions across the thick lipoial boundary layers [ 11. The release of iron from its carrier is mediated by a ferri-reductase but assay of this activity was severely hampered by having to use very turbid cell extracts and also by the facility with which the ensuing ferrous ion reoxidized and then recombined with mycobactin [l] . Very little could therefore be learnt about the enzyme. In this paper we describe an improved method for determining its activity, which may have a general applicability to other microbial iron transport systems, and are now able to describe some of its properties.

Coordination isomers of biological iron transport compounds III. (1) transport of A-cis-chromic desferriferrichrome by Ustilago sphaerogena

Microbial iron transport studies of the structure and conformation dependent ferrichrome uptake system in Ustilago sphaerogena have been limited previously to kinetically labile metal ions such as the native ferrichrome complex and the aluminum(III) and gallium(III) analogs. Although two coordination isomers are possible (λ- cis amd δ- cis), no information can be obtained concerning their biological activity using kinetically labile complexes. In this report, both the ligand and chromic ion moieties of kinetically inert λ- cis-chromic [ 14C]-desferriferrichrome are shown to be taken up in Ustilago sphaerogena at rates comparable to that of ferrichrome. The λ- cis coordination isomer must be therefore at least one of the biologically active isomers and the transport system cannot rely on the rapid isomerization or dissociation of the labile ferric complex.

Role of microbial iron transport compounds in bacterial spoilage of eggs.

Microbial iron transport compounds, belonging either to the hydroxamate family excreted by pseudomonads, or to the phenolate family excreted by salmonellae, reverse the bacteriostatic effect of conalbumin on the growth of these bacteria in egg white. The presence of microgram quantities of these compounds permits both salmonellae and pseudomonads to reach dense populations in egg white. The role of these iron transport compounds in bacterial egg spoilage is discussed.