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[PMID]:28432145
[Au] Autor:Saha P; Yeoh BS; Olvera RA; Xiao X; Singh V; Awasthi D; Subramanian BC; Chen Q; Dikshit M; Wang Y; Parent CA; Vijay-Kumar M
[Ad] Endereço:Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA 16802.
[Ti] Título:Bacterial Siderophores Hijack Neutrophil Functions.
[So] Source:J Immunol;198(11):4293-4303, 2017 Jun 01.
[Is] ISSN:1550-6606
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Neutrophils are the primary immune cells that respond to inflammation and combat microbial transgression. To thrive, the bacteria residing in their mammalian host have to withstand the antibactericidal responses of neutrophils. We report that enterobactin (Ent), a catecholate siderophore expressed by , inhibited PMA-induced generation of reactive oxygen species (ROS) and neutrophil extracellular traps (NETs) in mouse and human neutrophils. Ent also impaired the degranulation of primary granules and inhibited phagocytosis and bactericidal activity of neutrophils, without affecting their migration and chemotaxis. Molecular analysis revealed that Ent can chelate intracellular labile iron that is required for neutrophil oxidative responses. Other siderophores (pyoverdine, ferrichrome, deferoxamine) likewise inhibited ROS and NETs in neutrophils, thus indicating that the chelation of iron may largely explain their inhibitory effects. To counter iron theft by Ent, neutrophils rely on the siderophore-binding protein lipocalin 2 (Lcn2) in a "tug-of-war" for iron. The inhibition of neutrophil ROS and NETs by Ent was augmented in Lcn2-deficient neutrophils compared with wild-type neutrophils but was rescued by the exogenous addition of recombinant Lcn2. Taken together, our findings illustrate the novel concept that microbial siderophore's iron-scavenging property may serve as an antiradical defense system that neutralizes the immune functions of neutrophils.
[Mh] Termos MeSH primário: Enterobactina/metabolismo
Enterobactina/farmacologia
Armadilhas Extracelulares/imunologia
Neutrófilos/efeitos dos fármacos
Neutrófilos/fisiologia
Sideróforos/farmacologia
[Mh] Termos MeSH secundário: Animais
Quimiotaxia/efeitos dos fármacos
Enterobactina/química
Escherichia coli/química
Armadilhas Extracelulares/efeitos dos fármacos
Seres Humanos
Ferro/metabolismo
Lipocalina-2/genética
Lipocalina-2/metabolismo
Lipocalina-2/farmacologia
Camundongos
Neutrófilos/imunologia
Neutrófilos/patologia
Fagocitose/efeitos dos fármacos
Sideróforos/metabolismo
Acetato de Tetradecanoilforbol/farmacologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Lipocalin-2); 0 (Siderophores); 28384-96-5 (Enterobactin); E1UOL152H7 (Iron); NI40JAQ945 (Tetradecanoylphorbol Acetate)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:AIM; IM
[Da] Data de entrada para processamento:170423
[St] Status:MEDLINE
[do] DOI:10.4049/jimmunol.1700261


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[PMID]:27795321
[Au] Autor:Roy EM; Griffith KL
[Ad] Endereço:Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA.
[Ti] Título:Characterization of a Novel Iron Acquisition Activity That Coordinates the Iron Response with Population Density under Iron-Replete Conditions in Bacillus subtilis.
[So] Source:J Bacteriol;199(1), 2017 Jan 01.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Iron is an essential micronutrient required for the viability of many organisms. Under oxidizing conditions, ferric iron is highly insoluble (∼10 to 10 M), yet bacteria typically require ∼10 M for survival. To overcome this disparity, many bacteria have adopted the use of extracellular iron-chelating siderophores coupled with specific iron-siderophore uptake systems. In the case of Bacillus subtilis, undomesticated strains produce the siderophore bacillibactin. However, many laboratory strains, e.g., JH642, have lost the ability to produce bacillibactin during the process of domestication. In this work, we identified a novel iron acquisition activity from strain JH642 that accumulates in the growth medium and coordinates the iron response with population density. The molecule(s) responsible for this activity was named elemental Fe(II/III) (Efe) acquisition factor because efeUOB (ywbLMN) is required for its activity. Unlike most iron uptake molecules, including siderophores and iron reductases, Efe acquisition factor is present under iron-replete conditions and is regulated independently of Fur repressor. Restoring bacillibactin production in strain JH642 inhibits the activity of Efe acquisition factor, presumably by sequestering available iron. A similar iron acquisition activity is produced from a mutant of Escherichia coli unable to synthesize the siderophore enterobactin. Given the conservation of efeUOB and its regulation by catecholic siderophores in B. subtilis and E. coli, we speculate that Efe acquisition factor is utilized by many bacteria, serves as an alternative to Fur-mediated iron acquisition systems, and provides cells with biologically available iron that would normally be inaccessible during aerobic growth under iron-replete conditions. IMPORTANCE: Iron is an essential micronutrient required for a variety of biological processes, yet ferric iron is highly insoluble during aerobic growth. In this work, we identified a novel iron acquisition activity that coordinates the iron response with population density in laboratory strains of Bacillus subtilis We named the molecule(s) responsible for this activity elemental Fe(II/III) (Efe) acquisition factor after the efeUOB (ywbLMN) operon required for its uptake into cells. Unlike most iron uptake systems, Efe acquisition factor is present under iron-replete conditions and is regulated independently of Fur, the master regulator of the iron response. We speculate that Efe acquisition factor is highly conserved among bacteria and serves as a backup to Fur-mediated iron acquisition systems.
[Mh] Termos MeSH primário: Bacillus subtilis/metabolismo
Proteínas de Transporte/metabolismo
Regulação Bacteriana da Expressão Gênica/fisiologia
Ferro/metabolismo
[Mh] Termos MeSH secundário: Bacillus subtilis/genética
Transporte Biológico
Proteínas de Transporte/genética
Enterobactina/genética
Enterobactina/metabolismo
Mutação
Oligopeptídeos/genética
Oligopeptídeos/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Carrier Proteins); 0 (Oligopeptides); 0 (bacillibactin); 28384-96-5 (Enterobactin); E1UOL152H7 (Iron)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170714
[Lr] Data última revisão:
170714
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161101
[St] Status:MEDLINE


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[PMID]:27736645
[Au] Autor:Keogh D; Tay WH; Ho YY; Dale JL; Chen S; Umashankar S; Williams RBH; Chen SL; Dunny GM; Kline KA
[Ad] Endereço:Singapore Centre for Environmental Life Science Engineering, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore.
[Ti] Título:Enterococcal Metabolite Cues Facilitate Interspecies Niche Modulation and Polymicrobial Infection.
[So] Source:Cell Host Microbe;20(4):493-503, 2016 Oct 12.
[Is] ISSN:1934-6069
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Enterococcus faecalis is frequently associated with polymicrobial infections of the urinary tract, indwelling catheters, and surgical wound sites. E. faecalis co-exists with Escherichia coli and other pathogens in wound infections, but mechanisms that govern polymicrobial colonization and pathogenesis are poorly defined. During infection, bacteria must overcome multiple host defenses, including nutrient iron limitation, to persist and cause disease. In this study, we investigated the contribution of E. faecalis to mixed-species infection when iron availability is restricted. We show that E. faecalis significantly augments E. coli biofilm growth and survival in vitro and in vivo by exporting L-ornithine. This metabolic cue facilitates E. coli biosynthesis of the enterobactin siderophore, allowing E. coli growth and biofilm formation in iron-limiting conditions that would otherwise restrict its growth. Thus, E. faecalis modulates its local environment by contributing growth-promoting cues that allow co-infecting organisms to overcome iron limitation and promotes polymicrobial infections.
[Mh] Termos MeSH primário: Coinfecção/microbiologia
Enterococcus faecalis/metabolismo
Escherichia coli/efeitos dos fármacos
Escherichia coli/crescimento & desenvolvimento
Interações Microbianas
Ornitina/metabolismo
[Mh] Termos MeSH secundário: Animais
Biofilmes/crescimento & desenvolvimento
Infecções Relacionadas a Cateter/microbiologia
Modelos Animais de Doenças
Enterobactina/metabolismo
Escherichia coli/fisiologia
Feminino
Ferro/metabolismo
Camundongos Endogâmicos C57BL
Viabilidade Microbiana/efeitos dos fármacos
Infecções Urinárias/microbiologia
Infecção dos Ferimentos/microbiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
28384-96-5 (Enterobactin); E1UOL152H7 (Iron); E524N2IXA3 (Ornithine)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:171013
[Lr] Data última revisão:
171013
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161014
[St] Status:MEDLINE


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[PMID]:27539322
[Au] Autor:Li B; Li N; Yue Y; Liu X; Huang Y; Gu L; Xu S
[Ad] Endereço:Key Laboratory of Rare and Uncommon Diseases, Department of Microbiology, Institute of Basic Medicine, Shandong Academy of Medical Sciences, Jinan 250062, China; State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan 250100, China. Electronic address: bingq
[Ti] Título:An unusual crystal structure of ferric-enterobactin bound FepB suggests novel functions of FepB in microbial iron uptake.
[So] Source:Biochem Biophys Res Commun;478(3):1049-53, 2016 09 23.
[Is] ISSN:1090-2104
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Iron acquisition by siderophores is critical for the survival of most bacteria. Enterobactin is a kind of catechol siderophore that exhibits the highest affinity to iron atoms secreted by E. coli and several other species of Enterobacteriaceae. The periplasmic binding protein (PBP) FepB can transport ferric-enterobactin (Fe-Ent) from the outer membrane to the membrane-associated ATP-binding cassette transport system in E. coli. To elucidate this process, we solved the crystal structure of FepB in complex with Fe-Ent at a resolution of 1.8 Å. Consistent with previously reported NMR results, our crystal structure shows that, similar to the other type III PBPs, the FepB structure was folded with separated globular N- and C-termini linked by a long α-helix. Additionally, the structure showed that the Fe-Ent bound to the cleft between the N- and C-terminal domains. Exceptionally, FepB differs from the other known siderophore binding PBPs in that it forms a trimer by capturing four Fe-Ents that can each contribute to FepB trimerization. Dynamic light-scattering experiments are consistent with the structural observations and indicate that FepB forms a trimer in a Fe-Ent-dependent manner.
[Mh] Termos MeSH primário: Enterobactina/metabolismo
Proteínas de Escherichia coli/metabolismo
Escherichia coli/metabolismo
Ferro/metabolismo
Proteínas de Membrana Transportadoras/metabolismo
Proteínas Periplásmicas/metabolismo
[Mh] Termos MeSH secundário: Transporte Biológico
Cristalografia por Raios X
Enterobactina/química
Proteínas de Escherichia coli/química
Proteínas de Membrana Transportadoras/química
Modelos Biológicos
Modelos Moleculares
Proteínas Periplásmicas/química
Polímeros
Ligação Proteica
Multimerização Proteica
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Escherichia coli Proteins); 0 (Membrane Transport Proteins); 0 (Periplasmic Proteins); 0 (Polymers); 0 (fepB protein, E coli); 28384-96-5 (Enterobactin); E1UOL152H7 (Iron)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:171127
[Lr] Data última revisão:
171127
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160820
[St] Status:MEDLINE


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[PMID]:27470582
[Au] Autor:Pakarian P; Pawelek PD
[Ad] Endereço:Department of Chemistry and Biochemistry, Concordia University, 7141 Sherbrooke St., W., Montreal, H4B 1R6, Quebec, Canada.
[Ti] Título:Intracellular co-localization of the Escherichia coli enterobactin biosynthetic enzymes EntA, EntB, and EntE.
[So] Source:Biochem Biophys Res Commun;478(1):25-32, 2016 09 09.
[Is] ISSN:1090-2104
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Bacteria utilize small-molecule iron chelators called siderophores to support growth in low-iron environments. The Escherichia coli catecholate siderophore enterobactin is synthesized in the cytoplasm upon iron starvation. Seven enzymes are required for enterobactin biosynthesis: EntA-F, H. Given that EntB-EntE and EntA-EntE interactions have been reported, we investigated a possible EntA-EntB-EntE interaction in E. coli cells. We subcloned the E. coli entA and entB genes into bacterial adenylate cylase two-hybrid (BACTH) vectors allowing for co-expression of EntA and EntB with N-terminal fusions to the adenylate cyclase fragments T18 or T25. BACTH constructs were functionally validated using the CAS assay and growth studies. Co-transformants expressing T18/T25-EntA and T25/T18-EntB exhibited positive two-hybrid signals indicative of an intracellular EntA-EntB interaction. To gain further insights into the interaction interface, we performed computational docking in which an experimentally validated EntA-EntE model was docked to the EntB crystal structure. The resulting model of the EntA-EntB-EntE ternary complex predicted that the IC domain of EntB forms direct contacts with both EntA and EntE. BACTH constructs that expressed the isolated EntB IC domain fused to T18/T25 were prepared in order to investigate interactions with T25/T18-EntA and T25/T18-EntE. CAS assays and growth studies demonstrated that T25-IC co-expressed with the EntB ArCP domain could complement the E. coli entB(-) phenotype. In agreement with the ternary complex model, BACTH assays demonstrated that the EntB IC domain interacts with both EntA and EntE.
[Mh] Termos MeSH primário: Enterobactina/metabolismo
Proteínas de Escherichia coli/metabolismo
Escherichia coli/metabolismo
Hidrolases/metabolismo
Ligases/metabolismo
Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo
Mapas de Interação de Proteínas
[Mh] Termos MeSH secundário: Escherichia coli/química
Escherichia coli/citologia
Proteínas de Escherichia coli/análise
Hidrolases/análise
Ligases/análise
Simulação de Acoplamento Molecular
Oxirredutases atuantes sobre Doadores de Grupo CH-CH/análise
Domínios e Motivos de Interação entre Proteínas
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Escherichia coli Proteins); 28384-96-5 (Enterobactin); EC 1.3.- (Oxidoreductases Acting on CH-CH Group Donors); EC 1.3.1.28 (entA protein, E coli); EC 3.- (Hydrolases); EC 3.3.2.1 (isochorismatase); EC 6.- (Ligases); EC 6.5.- (2,3-dihydroxybenzoate-AMP ligase, E coli)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:171126
[Lr] Data última revisão:
171126
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160730
[St] Status:MEDLINE


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[PMID]:27310257
[Au] Autor:Peralta DR; Adler C; Corbalán NS; Paz García EC; Pomares MF; Vincent PA
[Ad] Endereço:Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT and Instituto de Química Biológica "Dr. Bernabé Bloj", Facultad de Bioquímica, Química y Farmacia, UNT. Chacabuco 461, T4000ILI -San Miguel de Tucumán, Tucumán, Argentina.
[Ti] Título:Enterobactin as Part of the Oxidative Stress Response Repertoire.
[So] Source:PLoS One;11(6):e0157799, 2016.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Microorganisms produce siderophores to facilitate iron uptake and even though this trait has been extensively studied, there is growing evidence suggesting that siderophores may have other physiological roles aside from iron acquisition. In support of this notion, we previously linked the archetypal siderophore enterobactin with oxidative stress alleviation. To further characterize this association, we studied the sensitivity of Escherichia coli strains lacking different components of the enterobactin system to the classical oxidative stressors hydrogen peroxide and paraquat. We observed that strains impaired in enterobactin production, uptake and hydrolysis were more susceptible to the oxidative damage caused by both compounds than the wild-type strain. In addition, meanwhile iron supplementation had little impact on the sensitivity, the reducing agent ascorbic acid alleviated the oxidative stress and therefore significantly decreased the sensitivity to the stressors. This indicated that the enterobactin-mediated protection is independent of its ability to scavenge iron. Furthermore, enterobactin supplementation conferred resistance to the entE mutant but did not have any protective effect on the fepG and fes mutants. Thus, we inferred that only after enterobactin is hydrolysed by Fes in the cell cytoplasm and iron is released, the free hydroxyl groups are available for radical stabilization. This hypothesis was validated testing the ability of enterobactin to scavenge radicals in vitro. Given the strong connection between enterobactin and oxidative stress, we studied the transcription of the entE gene and the concomitant production of the siderophore in response to such kind of stress. Interestingly, we observed that meanwhile iron represses the expression and production of the siderophore, hydrogen peroxide and paraquat favour these events even if iron is present. Our results support the involvement of enterobactin as part of the oxidative stress response and highlight the existence of a novel regulation mechanism for enterobactin biosynthesis.
[Mh] Termos MeSH primário: Enterobactina/biossíntese
Escherichia coli/genética
Regulação da Expressão Gênica
Sideróforos/biossíntese
Estresse Fisiológico/genética
[Mh] Termos MeSH secundário: Antioxidantes/farmacologia
Ácido Ascórbico/farmacologia
Hidrolases de Éster Carboxílico/genética
Hidrolases de Éster Carboxílico/metabolismo
Cloretos/farmacologia
Enterobactina/genética
Escherichia coli/efeitos dos fármacos
Escherichia coli/metabolismo
Proteínas de Escherichia coli/genética
Proteínas de Escherichia coli/metabolismo
Compostos Férricos/farmacologia
Peróxido de Hidrogênio/antagonistas & inibidores
Peróxido de Hidrogênio/farmacologia
Hidrólise
Ferro/metabolismo
Ligases/genética
Ligases/metabolismo
Mutação
Oxidantes/antagonistas & inibidores
Oxidantes/farmacologia
Oxirredução
Estresse Oxidativo
Paraquat/antagonistas & inibidores
Paraquat/farmacologia
Sideróforos/genética
Transcrição Genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Antioxidants); 0 (Chlorides); 0 (Escherichia coli Proteins); 0 (Ferric Compounds); 0 (Oxidants); 0 (Siderophores); 28384-96-5 (Enterobactin); BBX060AN9V (Hydrogen Peroxide); E1UOL152H7 (Iron); EC 3.1.1.- (Carboxylic Ester Hydrolases); EC 3.1.1.- (ferric enterobactin esterase, E coli); EC 6.- (Ligases); EC 6.5.- (2,3-dihydroxybenzoate-AMP ligase, E coli); PLG39H7695 (Paraquat); PQ6CK8PD0R (Ascorbic Acid); U38V3ZVV3V (ferric chloride)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170713
[Lr] Data última revisão:
170713
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160617
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0157799


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[PMID]:27162326
[Au] Autor:Raines DJ; Moroz OV; Blagova EV; Turkenburg JP; Wilson KS; Duhme-Klair AK
[Ad] Endereço:Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom;
[Ti] Título:Bacteria in an intense competition for iron: Key component of the Campylobacter jejuni iron uptake system scavenges enterobactin hydrolysis product.
[So] Source:Proc Natl Acad Sci U S A;113(21):5850-5, 2016 May 24.
[Is] ISSN:1091-6490
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:To acquire essential Fe(III), bacteria produce and secrete siderophores with high affinity and selectivity for Fe(III) to mediate its uptake into the cell. Here, we show that the periplasmic binding protein CeuE of Campylobacter jejuni, which was previously thought to bind the Fe(III) complex of the hexadentate siderophore enterobactin (Kd ∼ 0.4 ± 0.1 µM), preferentially binds the Fe(III) complex of the tetradentate enterobactin hydrolysis product bis(2,3-dihydroxybenzoyl-l-Ser) (H5-bisDHBS) (Kd = 10.1 ± 3.8 nM). The protein selects Λ-configured [Fe(bisDHBS)](2-) from a pool of diastereomeric Fe(III)-bisDHBS species that includes complexes with metal-to-ligand ratios of 1:1 and 2:3. Cocrystal structures show that, in addition to electrostatic interactions and hydrogen bonding, [Fe(bisDHBS)](2-) binds through coordination of His227 and Tyr288 to the iron center. Similar binding is observed for the Fe(III) complex of the bidentate hydrolysis product 2,3-dihydroxybenzoyl-l-Ser, [Fe(monoDHBS)2](3-) The mutation of His227 and Tyr288 to noncoordinating residues (H227L/Y288F) resulted in a substantial loss of affinity for [Fe(bisDHBS)](2-) (Kd ∼ 0.5 ± 0.2 µM). These results suggest a previously unidentified role for CeuE within the Fe(III) uptake system of C. jejuni, provide a molecular-level understanding of the underlying binding pocket adaptations, and rationalize reports on the use of enterobactin hydrolysis products by C. jejuni, Vibrio cholerae, and other bacteria with homologous periplasmic binding proteins.
[Mh] Termos MeSH primário: Proteínas de Bactérias/química
Campylobacter jejuni/metabolismo
Proteínas de Transporte/química
Complexos de Coordenação/química
Enterobactina/metabolismo
Ferro/metabolismo
Sideróforos/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Benzoatos/química
Benzoatos/metabolismo
Campylobacter jejuni/genética
Proteínas de Transporte/genética
Proteínas de Transporte/metabolismo
Complexos de Coordenação/metabolismo
Cristalografia por Raios X
Expressão Gênica
Hidrazonas/química
Hidrazonas/metabolismo
Ligações de Hidrogênio
Hidrólise
Transporte de Íons
Ligantes
Modelos Moleculares
Mutação
Ligação Proteica
Eletricidade Estática
Estereoisomerismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Benzoates); 0 (Carrier Proteins); 0 (Coordination Complexes); 0 (Hydrazones); 0 (Ligands); 0 (Siderophores); 0 (ceuE protein, Campylobacter coli); 28384-96-5 (Enterobactin); E1UOL152H7 (Iron)
[Em] Mês de entrada:1612
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160511
[St] Status:MEDLINE
[do] DOI:10.1073/pnas.1520829113


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[PMID]:27118028
[Au] Autor:Workman DG; Hunter M; Dover LG; Tétard D
[Ad] Endereço:Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, United Kingdom.
[Ti] Título:Synthesis of novel Iron(III) chelators based on triaza macrocycle backbone and 1-hydroxy-2(H)-pyridin-2-one coordinating groups and their evaluation as antimicrobial agents.
[So] Source:J Inorg Biochem;160:49-58, 2016 Jul.
[Is] ISSN:1873-3344
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Several novel chelators based on 1-hydroxy-2(1H)-pyridinone coordinating groups decorating a triaza macrocyclic backbone scaffold were synthesised as potential powerful Fe(3+) chelators capable of competing with bacterial siderophores. In particular, a novel chloromethyl derivative of 1-hydroxy-2(1H)-pyridinone exploiting a novel protective group for this family of coordinating groups was developed. These are the first examples of hexadentate chelators based on 1-hydroxy-2(1H)-pyridinone to be shown to have a biostatic activity against a range of pathogenic bacteria. Their efficacy as biostatic agents was assessed revealing that minor variations in the structure of the chelator can affect efficacy profoundly. The minimal inhibitory concentrations of our best tested novel chelators approach or are comparable to those for 1,4,7-tris(3-hydroxy-6-methyl-2-pyridylmethyl)-1,4,7-triazacyclononane, the best Fe(3+) chelator known to date. The retarding effect these chelators have on microbial growth suggests that they could have a potential application as a co-active alongside antibiotics in the fight against infections.
[Mh] Termos MeSH primário: Anti-Infecciosos/síntese química
Compostos Heterocíclicos/química
Quelantes de Ferro/síntese química
Ferro/metabolismo
Piridonas/química
[Mh] Termos MeSH secundário: Anti-Infecciosos/farmacologia
Candida albicans/efeitos dos fármacos
Candida albicans/crescimento & desenvolvimento
Candida albicans/metabolismo
Desenho de Drogas
Enterobactina/química
Furanos/química
Bactérias Gram-Negativas/efeitos dos fármacos
Bactérias Gram-Negativas/crescimento & desenvolvimento
Bactérias Gram-Negativas/metabolismo
Bactérias Gram-Positivas/efeitos dos fármacos
Bactérias Gram-Positivas/crescimento & desenvolvimento
Bactérias Gram-Positivas/metabolismo
Ferro/química
Quelantes de Ferro/farmacologia
Testes de Sensibilidade Microbiana
Oligopeptídeos/química
Poliaminas/química
Solventes/química
Relação Estrutura-Atividade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Infective Agents); 0 (Furans); 0 (Heterocyclic Compounds); 0 (Iron Chelating Agents); 0 (Oligopeptides); 0 (Polyamines); 0 (Pyridones); 0 (Solvents); 0 (bacillibactin); 03K6SX4V2J (diethylenetriamine); 28384-96-5 (Enterobactin); 3N8FZZ6PY4 (tetrahydrofuran); 4730-54-5 (1,4,7-triazacyclononane); E1UOL152H7 (Iron); YO3915897S (1-hydroxy-2(1H)-pyridinone)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170626
[Lr] Data última revisão:
170626
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160428
[St] Status:MEDLINE


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[PMID]:27086082
[Au] Autor:Pakarian P; Pawelek PD
[Ad] Endereço:Department of Chemistry and Biochemistry, Concordia University, 7141 Sherbrooke St., W., Montreal, Quebec, H4B 1R6, Canada.
[Ti] Título:Subunit orientation in the Escherichia coli enterobactin biosynthetic EntA-EntE complex revealed by a two-hybrid approach.
[So] Source:Biochimie;127:1-9, 2016 Aug.
[Is] ISSN:1638-6183
[Cp] País de publicação:France
[La] Idioma:eng
[Ab] Resumo:The siderophore enterobactin is synthesized by the enzymes EntA-F and EntH in the Escherichia coli cytoplasm. We previously reported in vitro evidence of an interaction between tetrameric EntA and monomeric EntE. Here we used bacterial adenylate cyclase two-hybrid (BACTH) assays to demonstrate that the E. coli EntA-EntE interaction occurs intracellularly. Furthermore, to obtain information on subunit orientation in the EntA-EntE complex, we fused BACTH reporter fragments T18 and T25 to EntA and EntE in both N-terminal and C-terminal orientations. To validate functionality of our fusion proteins, we performed Chrome Azurol S (CAS) assays using E. coli entE(-) and entA(-) knockout strains transformed with our BACTH constructs. We found that transformants expressing N-terminal and C-terminal T18/T25 fusions to EntE exhibited CAS signals, indicating that these constructs could rescue the entE(-) phenotype. While expression of EntA with N-terminal T18/T25 fusions exhibited CAS signals, C-terminal fusions did not, presumably due to disruption of the EntA tetramer in vivo. Bacterial growth assays supported our CAS findings. Co-transformation of functional T18/T25 fusions into cya(-)E. coli BTH101 cells resulted in positive BACTH signals only when T18/T25 fragments were fused to the N-termini of both EntA and EntE. Co-expression of N-terminally fused EntA with C-terminally fused EntE resulted in no detectable BACTH signal. Analysis of protein expression by Western blotting confirmed that the loss of BACTH signal was not due to impaired expression of fusion proteins. Based on our results, we propose that the N-termini of EntA and EntE are proximal in the intracellular complex, while the EntA N-terminus and EntE C-terminus are distal. A protein-protein docking simulation using SwarmDock was in agreement with our experimental observations.
[Mh] Termos MeSH primário: Enterobactina/biossíntese
Proteínas de Escherichia coli/química
Proteínas de Escherichia coli/metabolismo
Escherichia coli/metabolismo
Ligases/química
Ligases/metabolismo
Oxirredutases atuantes sobre Doadores de Grupo CH-CH/química
Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo
Subunidades Proteicas/metabolismo
[Mh] Termos MeSH secundário: Escherichia coli/citologia
Escherichia coli/enzimologia
Espaço Intracelular/metabolismo
Simulação de Acoplamento Molecular
Multimerização Proteica
Estrutura Quaternária de Proteína
Técnicas do Sistema de Duplo-Híbrido
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Escherichia coli Proteins); 0 (Protein Subunits); 28384-96-5 (Enterobactin); EC 1.3.- (Oxidoreductases Acting on CH-CH Group Donors); EC 1.3.1.28 (entA protein, E coli); EC 6.- (Ligases); EC 6.5.- (2,3-dihydroxybenzoate-AMP ligase, E coli)
[Em] Mês de entrada:1701
[Cu] Atualização por classe:170123
[Lr] Data última revisão:
170123
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160418
[St] Status:MEDLINE


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[PMID]:26954697
[Au] Autor:Su Q; Guan T; He Y; Lv H
[Ad] Endereço:The Laboratory for Functional Omics and Innovative Chinese Medicine, Innovative Drug Research Center, Chongqing University , Chongqing 401331, P.R. China.
[Ti] Título:Siderophore Biosynthesis Governs the Virulence of Uropathogenic Escherichia coli by Coordinately Modulating the Differential Metabolism.
[So] Source:J Proteome Res;15(4):1323-32, 2016 Apr 01.
[Is] ISSN:1535-3907
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Urinary tract infections impose substantial health burdens on women worldwide. Urinary tract infections often incur a high risk of recurrence and antibiotic resistance, and uropathogenic E. coli accounts for approximately 80% of clinically acquired cases. The diagnosis of, treatment of, and drug development for urinary tract infections remain substantial challenges due to the complex pathogenesis of this condition. The clinically isolated UPEC 83972 strain was found to produce four siderophores: yersiniabactin, aerobactin, salmochelin, and enterobactin. The biosyntheses of some of these siderophores implies that the virulence of UPEC is mediated via the targeting of primary metabolism. However, the differential modulatory roles of siderophore biosyntheses on the differential metabolomes of UPEC and non-UPEC strains remain incompletely understood. In the present study, we sought to investigate how the differential metabolomes can be used to distinguish UPEC from non-UPEC strains and to determine the associated regulatory roles of siderophore biosynthesis. Our results are the first to demonstrate that the identified differential metabolomes strongly differentiated UPEC from non-UPEC strains. Furthermore, we performed metabolome assays of mutants with different patterns of siderophore deletions; the data revealed that the mutations of all four siderophores exerted a stronger modulatory role on the differential metabolomes of the UPEC and non-UPEC strains relative to the mutation of any single siderophore and that this modulatory role primarily involved amino acid metabolism, oxidative phosphorylation in the carbon fixation pathway, and purine and pyrimidine metabolism. Surprisingly, the modulatory roles were strongly dependent on the type and number of mutated siderophores. Taken together, these results demonstrated that siderophore biosynthesis coordinately modulated the differential metabolomes and thus may indicate novel targets for virulence-based diagnosis, therapeutics, and drug development related to urinary tract infections.
[Mh] Termos MeSH primário: Enterobactina/análogos & derivados
Enterobactina/biossíntese
Glucosídeos/biossíntese
Ácidos Hidroxâmicos/metabolismo
Fenóis/metabolismo
Sideróforos/metabolismo
Tiazóis/metabolismo
Escherichia coli Uropatogênica/metabolismo
Escherichia coli Uropatogênica/patogenicidade
[Mh] Termos MeSH secundário: Aminoácidos/metabolismo
Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Ciclo do Carbono
Ciclo do Ácido Cítrico/fisiologia
Infecções por Escherichia coli/microbiologia
Infecções por Escherichia coli/patologia
Feminino
Deleção de Genes
Expressão Gênica
Seres Humanos
Espectroscopia de Ressonância Magnética
Metaboloma
Fosforilação Oxidativa
Purinas/metabolismo
Pirimidinas/metabolismo
Infecções Urinárias/microbiologia
Infecções Urinárias/patologia
Escherichia coli Uropatogênica/genética
Escherichia coli Uropatogênica/isolamento & purificação
Virulência
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Amino Acids); 0 (Bacterial Proteins); 0 (Glucosides); 0 (Hydroxamic Acids); 0 (Phenols); 0 (Purines); 0 (Pyrimidines); 0 (Siderophores); 0 (Thiazoles); 0 (salmochelin S4); 0 (yersiniabactin); 26198-65-2 (aerobactin); 28384-96-5 (Enterobactin)
[Em] Mês de entrada:1612
[Cu] Atualização por classe:161230
[Lr] Data última revisão:
161230
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160309
[St] Status:MEDLINE
[do] DOI:10.1021/acs.jproteome.6b00061



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