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[PMID]: 28863139 [Au] Autor: Aarts E; Ederveen THA; Naaijen J; Zwiers MP; Boekhorst J; Timmerman HM; Smeekens SP; Netea MG; Buitelaar JK; Franke B; van Hijum SAFT; Arias Vasquez A [Ad] Endereço: Centre for Cognitive Neuroimaging, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands. [Ti] Título: Gut microbiome in ADHD and its relation to neural reward anticipation. [So] Source: PLoS One;12(9):e0183509, 2017. [Is] ISSN: 1932-6203 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: BACKGROUND: Microorganisms in the human intestine (i.e. the gut microbiome) have an increasingly recognized impact on human health, including brain functioning. Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder associated with abnormalities in dopamine neurotransmission and deficits in reward processing and its underlying neuro-circuitry including the ventral striatum. The microbiome might contribute to ADHD etiology via the gut-brain axis. In this pilot study, we investigated potential differences in the microbiome between ADHD cases and undiagnosed controls, as well as its relation to neural reward processing. METHODS: We used 16S rRNA marker gene sequencing (16S) to identify bacterial taxa and their predicted gene functions in 19 ADHD and 77 control participants. Using functional magnetic resonance imaging (fMRI), we interrogated the effect of observed microbiome differences in neural reward responses in a subset of 28 participants, independent of diagnosis. RESULTS: For the first time, we describe gut microbial makeup of adolescents and adults diagnosed with ADHD. We found that the relative abundance of several bacterial taxa differed between cases and controls, albeit marginally significant. A nominal increase in the Bifidobacterium genus was observed in ADHD cases. In a hypothesis-driven approach, we found that the observed increase was linked to significantly enhanced 16S-based predicted bacterial gene functionality encoding cyclohexadienyl dehydratase in cases relative to controls. This enzyme is involved in the synthesis of phenylalanine, a precursor of dopamine. Increased relative abundance of this functionality was significantly associated with decreased ventral striatal fMRI responses during reward anticipation, independent of ADHD diagnosis and age. CONCLUSIONS: Our results show increases in gut microbiome predicted function of dopamine precursor synthesis between ADHD cases and controls. This increase in microbiome function relates to decreased neural responses to reward anticipation. Decreased neural reward anticipation constitutes one of the hallmarks of ADHD. [Mh] Termos MeSH primário: Transtorno do Deficit de Atenção com Hiperatividade/complicações Transtorno do Deficit de Atenção com Hiperatividade/microbiologia Gastroenteropatias/microbiologia Microbioma Gastrointestinal Recompensa [Mh] Termos MeSH secundário: Adolescente Adulto Bifidobacterium/isolamento & purificação Estudos de Coortes Feminino Gastroenteropatias/complicações Seres Humanos Imagem por Ressonância Magnética Masculino Meia-Idade Modelos Neurológicos Projetos Piloto Prefenato Desidratase/metabolismo RNA Ribossômico 16S/genética Resultado do Tratamento Adulto Jovem [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (RNA, Ribosomal, 16S); EC 4.2.1.- (cyclohexadienyl dehydratase); EC 4.2.1.51 (Prephenate Dehydratase) [Em] Mês de entrada: 1710 [Cu] Atualização por classe: 171024 [Lr] Data última revisão: 171024 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170902 [St] Status: MEDLINE [do] DOI: 10.1371/journal.pone.0183509

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[PMID]: 27600507 [Au] Autor: Basu D; Kahn JN; Li XP; Tumer NE [Ad] Endereço: Department of Plant Biology and Pathology, School of Environmental and Biological Sciences, Rutgers University, New Brunswick, New Jersey, USA. [Ti] Título: Conserved Arginines at the P-Protein Stalk Binding Site and the Active Site Are Critical for Ribosome Interactions of Shiga Toxins but Do Not Contribute to Differences in the Affinity of the A1 Subunits for the Ribosome. [So] Source: Infect Immun;84(12):3290-3301, 2016 Dec. [Is] ISSN: 1098-5522 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: The A1 subunits of Shiga toxin 1 (Stx1A1) and Shiga toxin 2 (Stx2A1) interact with the conserved C termini of ribosomal-stalk P-proteins to remove a specific adenine from the sarcin/ricin loop. We previously showed that Stx2A1 has higher affinity for the ribosome and higher catalytic activity than Stx1A1. To determine if conserved arginines at the distal face of the active site contribute to the higher affinity of Stx2A1 for the ribosome, we mutated Arg172, Arg176, and Arg179 in both toxins. We show that Arg172 and Arg176 are more important than Arg179 for the depurination activity and toxicity of Stx1A1 and Stx2A1. Mutation of a single arginine reduced the depurination activity of Stx1A1 more than that of Stx2A1. In contrast, mutation of at least two arginines was necessary to reduce depurination by Stx2A1 to a level similar to that of Stx1A1. R176A and R172A/R176A mutations eliminated interaction of Stx1A1 and Stx2A1 with ribosomes and with the stalk, while mutation of Arg170 at the active site reduced the binding affinity of Stx1A1 and Stx2A1 for the ribosome, but not for the stalk. These results demonstrate that conserved arginines at the distal face of the active site are critical for interactions of Stx1A1 and Stx2A1 with the stalk, while a conserved arginine at the active site is critical for non-stalk-specific interactions with the ribosome. Arginine mutations at either site reduced ribosome interactions of Stx1A1 and Stx2A1 similarly, indicating that conserved arginines are critical for ribosome interactions but do not contribute to the higher affinity of Stx2A1 for the ribosome. [Mh] Termos MeSH primário: Sequência Conservada Proteínas de Escherichia coli/metabolismo Complexos Multienzimáticos/metabolismo Prefenato Desidratase/metabolismo Ribossomos/metabolismo Saccharomyces/metabolismo Toxinas Shiga/metabolismo [Mh] Termos MeSH secundário: Animais Sítios de Ligação Proteínas de Escherichia coli/genética Regulação Bacteriana da Expressão Gênica/fisiologia Modelos Moleculares Complexos Multienzimáticos/genética Mutação Plasmídeos Prefenato Desidratase/genética Ligação Proteica Conformação Proteica Subunidades Proteicas RNA Fúngico/metabolismo Ratos Ribossomos/química Saccharomyces/genética Toxinas Shiga/química [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Escherichia coli Proteins); 0 (Multienzyme Complexes); 0 (P-protein, E coli); 0 (Protein Subunits); 0 (RNA, Fungal); 0 (Shiga Toxins); EC 4.2.1.51 (Prephenate Dehydratase) [Em] Mês de entrada: 1705 [Cu] Atualização por classe: 170518 [Lr] Data última revisão: 170518 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 160908 [St] Status: MEDLINE

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[PMID]: 27290727 [Au] Autor: Shlaifer I; Turnbull JL [Ad] Endereço: Department of Chemistry and Biochemistry, Concordia University, 7141 Sherbrooke St. West, Montréal, QC, H4B 1R6, Canada. [Ti] Título: Characterization of two key enzymes for aromatic amino acid biosynthesis in symbiotic archaea. [So] Source: Extremophiles;20(4):503-14, 2016 Jul. [Is] ISSN: 1433-4909 [Cp] País de publicação: Germany [La] Idioma: eng [Ab] Resumo: Biosynthesis of L-tyrosine (L-Tyr) and L-phenylalanine (L-Phe) is directed by the interplay of three enzymes. Chorismate mutase (CM) catalyzes the rearrangement of chorismate to prephenate, which can be either converted to hydroxyphenylpyruvate by prephenate dehydrogenase (PD) or to phenylpyruvate by prephenate dehydratase (PDT). This work reports the first characterization of a trifunctional PD-CM-PDT from the smallest hyperthermophilic archaeon Nanoarchaeum equitans and a bifunctional CM-PD from its host, the crenarchaeon Ignicoccus hospitalis. Hexa-histidine tagged proteins were expressed in Escherichia coli and purified by affinity chromatography. Specific activities determined for the trifunctional enzyme were 21, 80, and 30 U/mg for CM, PD, and PDT, respectively, and 47 and 21 U/mg for bifunctional CM and PD, respectively. Unlike most PDs, these two archaeal enzymes were insensitive to regulation by L-Tyr and preferred NADP(+) to NAD(+) as a cofactor. Both the enzymes were highly thermally stable and exhibited maximal activity at 90 °C. N. equitans PDT was feedback inhibited by L-Phe (Ki = 0.8 µM) in a non-competitive fashion consistent with L-Phe's combination at a site separate from that of prephenate. Our results suggest that PD from the unique symbiotic archaeal pair encompass a distinct subfamily of prephenate dehydrogenases with regard to their regulation and co-substrate specificity. [Mh] Termos MeSH primário: Proteínas Arqueais/metabolismo Corismato Mutase/metabolismo Desulfurococcaceae/enzimologia Nanoarchaeota/enzimologia Prefenato Desidratase/metabolismo Prefenato Desidrogenase/metabolismo [Mh] Termos MeSH secundário: Aminoácidos Aromáticos/biossíntese Proteínas Arqueais/química Proteínas Arqueais/genética Corismato Mutase/química Corismato Mutase/genética Desulfurococcaceae/fisiologia Estabilidade Enzimática Temperatura Alta Nanoarchaeota/fisiologia Nitrosaminas/metabolismo Prefenato Desidratase/química Prefenato Desidratase/genética Prefenato Desidrogenase/química Prefenato Desidrogenase/genética Especificidade por Substrato Simbiose [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Amino Acids, Aromatic); 0 (Archaeal Proteins); 0 (Nitrosamines); 91308-70-2 (N-nitroso-2-hydroxypropylamine); EC 1.3.1.12 (Prephenate Dehydrogenase); EC 4.2.1.51 (Prephenate Dehydratase); EC 5.4.99.5 (Chorismate Mutase) [Em] Mês de entrada: 1702 [Cu] Atualização por classe: 171013 [Lr] Data última revisão: 171013 [Sb] Subgrupo de revista: IM; S [Da] Data de entrada para processamento: 160613 [St] Status: MEDLINE [do] DOI: 10.1007/s00792-016-0840-z

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[PMID]: 27125254 [Au] Autor: El-Azaz J; de la Torre F; Ávila C; Cánovas FM [Ad] Endereço: Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, Málaga, 29071, Spain. [Ti] Título: Identification of a small protein domain present in all plant lineages that confers high prephenate dehydratase activity. [So] Source: Plant J;87(2):215-29, 2016 Jul. [Is] ISSN: 1365-313X [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: l-Phenylalanine serves as a building block for the biosynthesis of proteins, but also as a precursor for a wide range of plant-derived compounds essential for plants and animals. Plants can synthesize Phe within the plastids using arogenate as a precursor; however, an alternative pathway using phenylpyruvate as an intermediate, described for most microorganisms, has recently been proposed. The functionality of this pathway requires the existence of enzymes with prephenate dehydratase (PDT) activity (EC 4.2.1.51) in plants. Using phylogenetic studies, functional complementation assays in yeast and biochemical analysis, we have identified the enzymes displaying PDT activity in Pinus pinaster. Through sequence alignment comparisons and site-directed mutagenesis we have identified a 22-amino acid region conferring PDT activity (PAC domain) and a single Ala314 residue critical to trigger this activity. Our results demonstrate that all plant clades include PAC domain-containing ADTs, suggesting that the PDT activity, and thus the ability to synthesize Phe using phenylpyruvate as an intermediate, has been preserved throughout the evolution of plants. Moreover, this pathway together with the arogenate pathway gives plants a broad and versatile capacity to synthesize Phe and its derived compounds. PAC domain-containing enzymes are also present in green and red algae, and glaucophytes, the three emerging clades following the primary endosymbiont event resulting in the acquisition of plastids in eukaryotes. The evolutionary prokaryotic origin of this domain is discussed. [Mh] Termos MeSH primário: Pinus/genética Prefenato Desidratase/genética [Mh] Termos MeSH secundário: Aminoácidos Dicarboxílicos/metabolismo Cicloexenos/metabolismo Genes de Plantas/fisiologia Redes e Vias Metabólicas/fisiologia Fenilalanina/metabolismo Ácidos Fenilpirúvicos/metabolismo Filogenia Pinus/enzimologia Pinus/metabolismo Plantas Prefenato Desidratase/metabolismo Tirosina/análogos & derivados Tirosina/metabolismo [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Amino Acids, Dicarboxylic); 0 (Cyclohexenes); 0 (Phenylpyruvic Acids); 42HK56048U (Tyrosine); 47E5O17Y3R (Phenylalanine); 53078-86-7 (pretyrosine); EC 4.2.1.51 (Prephenate Dehydratase); X7CO62M413 (phenylpyruvic acid) [Em] Mês de entrada: 1709 [Cu] Atualização por classe: 170901 [Lr] Data última revisão: 170901 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 160430 [St] Status: MEDLINE [do] DOI: 10.1111/tpj.13195

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[PMID]: 25910239 [Au] Autor: Ge J; Yao SQ [Ad] Endereço: Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore. [Ti] Título: Chemical proteomics of host-pathogen interaction. [So] Source: Chem Biol;22(4):434-435, 2015 Apr 23. [Is] ISSN: 1879-1301 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: In less than two decades, activity-based protein profiling (ABPP) has expanded to become the de facto tool for the study of small molecule-protein interactions in a proteomic environment. In this issue, Na et al. (2015) present another ABPP method, which they called reactive probe-based chemical proteomics, to study host-pathogen interaction and subsequently identify the protein PheA as a potential key effector during the pathogen infection process. [Mh] Termos MeSH primário: Proteínas de Bactérias/metabolismo Interações Hospedeiro-Patógeno Prefenato Desidratase/metabolismo Proteômica Infecções por Salmonella/microbiologia Salmonella typhimurium/fisiologia [Mh] Termos MeSH secundário: Animais [Pt] Tipo de publicação: COMMENT; JOURNAL ARTICLE [Nm] Nome de substância: 0 (Bacterial Proteins); EC 4.2.1.51 (Prephenate Dehydratase) [Em] Mês de entrada: 1602 [Cu] Atualização por classe: 170921 [Lr] Data última revisão: 170921 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 150425 [St] Status: MEDLINE

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[PMID]: 25865312 [Au] Autor: Na HN; Yoo YH; Yoon CN; Lee JS [Ad] Endereço: Molecular Recognition Research Center, Korea Institute of Science and Technology, 39-1 Hawolgok-dong, Seoul 136-791, South Korea; Department of Biological Chemistry, University of Science & Technology, 113 Gwahank-ro, Yuseong-gu, Daejeon 305-333, South Korea. [Ti] Título: Unbiased proteomic profiling strategy for discovery of bacterial effector proteins reveals that Salmonella protein PheA is a host cell cycle regulator. [So] Source: Chem Biol;22(4):453-459, 2015 Apr 23. [Is] ISSN: 1879-1301 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: Salmonella utilizes a type III secretion system to inject bacterial effector proteins into the host cell cytosol. Once in the cytosol, these effectors hijack various biochemical pathways to regulate virulence. Despite the importance of effector proteins, especially for understanding host-pathogen interactions, a potentially large number of effectors are yet to be identified. Here, we demonstrate that unbiased chemical proteomic profiling using off-the-shelf fluorescent probes leads to the discovery of a host cell cycle regulator encoded in the Salmonella genome. Our profiling combined with bioinformatic analysis implicates 29 Salmonella as potential effectors. We follow up on the top candidate, chorismate mutase-P/prehenate dehydratase, PheA, and present evidence that PheA is an effector that mimics E2F7 transcription factor of the host cell and promotes G1/S cell cycle arrest. This validates our strategy and opens opportunities for effector identification in the future. [Mh] Termos MeSH primário: Proteínas de Bactérias/metabolismo Interações Hospedeiro-Patógeno Prefenato Desidratase/metabolismo Proteômica Infecções por Salmonella/microbiologia Salmonella typhimurium/fisiologia [Mh] Termos MeSH secundário: Animais Linhagem Celular Fator de Transcrição E2F7/genética Fator de Transcrição E2F7/metabolismo Eletroforese em Gel de Poliacrilamida Ensaio de Desvio de Mobilidade Eletroforética Corantes Fluorescentes/química Corantes Fluorescentes/metabolismo Pontos de Checagem da Fase G1 do Ciclo Celular Genoma Bacteriano Camundongos Microscopia de Fluorescência Proteoma/análise Pontos de Checagem da Fase S do Ciclo Celular Infecções por Salmonella/fisiopatologia Salmonella typhimurium/citologia Salmonella typhimurium/enzimologia Salmonella typhimurium/genética [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Bacterial Proteins); 0 (E2F7 Transcription Factor); 0 (Fluorescent Dyes); 0 (Proteome); EC 4.2.1.51 (Prephenate Dehydratase) [Em] Mês de entrada: 1602 [Cu] Atualização por classe: 170921 [Lr] Data última revisão: 170921 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 150414 [St] Status: MEDLINE

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[PMID]: 25583137 [Au] Autor: Giessen TW; Altegoer F; Nebel AJ; Steinbach RM; Bange G; Marahiel MA [Ad] Endereço: Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg (Germany); LOEWE Center for Synthetic Microbiology (Synmikro), Philipps-University Marburg, Hans-Meerwein-Strasse, 35032 Marburg (Germany). tobias.giessen@chemie.uni-marburg.de. [Ti] Título: A synthetic adenylation-domain-based tRNA-aminoacylation catalyst. [So] Source: Angew Chem Int Ed Engl;54(8):2492-6, 2015 Feb 16. [Is] ISSN: 1521-3773 [Cp] País de publicação: Germany [La] Idioma: eng [Ab] Resumo: The incorporation of non-proteinogenic amino acids represents a major challenge for the creation of functionalized proteins. The ribosomal pathway is limited to the 20-22 proteinogenic amino acids while nonribosomal peptide synthetases (NRPSs) are able to select from hundreds of different monomers. Introduced herein is a fusion-protein-based design for synthetic tRNA-aminoacylation catalysts based on combining NRPS adenylation domains and a small eukaryotic tRNA-binding domain (Arc1p-C). Using rational design, guided by structural insights and molecular modeling, the adenylation domain PheA was fused with Arc1p-C using flexible linkers and achieved tRNA-aminoacylation with both proteinogenic and non-proteinogenic amino acids. The resulting aminoacyl-tRNAs were functionally validated and the catalysts showed broad substrate specificity towards the acceptor tRNA. Our strategy shows how functional tRNA-aminoacylation catalysts can be created for bridging the ribosomal and nonribosomal worlds. This opens up new avenues for the aminoacylation of tRNAs with functional non-proteinogenic amino acids. [Mh] Termos MeSH primário: Aminoacil-tRNA Sintetases/metabolismo Aminoacilação de RNA de Transferência [Mh] Termos MeSH secundário: Aminoacil-tRNA Sintetases/química Aminoacil-tRNA Sintetases/genética Biocatálise Escherichia coli/enzimologia Proteínas de Escherichia coli/química Proteínas de Escherichia coli/metabolismo Complexos Multienzimáticos/química Complexos Multienzimáticos/metabolismo Prefenato Desidratase/química Prefenato Desidratase/metabolismo Engenharia de Proteínas [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Escherichia coli Proteins); 0 (Multienzyme Complexes); 0 (P-protein, E coli); EC 4.2.1.51 (Prephenate Dehydratase); EC 6.1.1.- (Amino Acyl-tRNA Synthetases) [Em] Mês de entrada: 1510 [Cu] Atualização por classe: 150213 [Lr] Data última revisão: 150213 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 150114 [St] Status: MEDLINE [do] DOI: 10.1002/anie.201410047

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[PMID]: 25275514 [Au] Autor: Sapp AM; Mogen AB; Almand EA; Rivera FE; Shaw LN; Richardson AR; Rice KC [Ad] Endereço: Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, United States of America. [Ti] Título: Contribution of the nos-pdt operon to virulence phenotypes in methicillin-sensitive Staphylococcus aureus. [So] Source: PLoS One;9(9):e108868, 2014. [Is] ISSN: 1932-6203 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: Nitric oxide (NO) is emerging as an important regulator of bacterial stress resistance, biofilm development, and virulence. One potential source of endogenous NO production in the pathogen Staphylococcus aureus is its NO-synthase (saNOS) enzyme, encoded by the nos gene. Although a role for saNOS in oxidative stress resistance, antibiotic resistance, and virulence has been recently-described, insights into the regulation of nos expression and saNOS enzyme activity remain elusive. To this end, transcriptional analysis of the nos gene in S. aureus strain UAMS-1 was performed, which revealed that nos expression increases during low-oxygen growth and is growth-phase dependent. Furthermore, nos is co-transcribed with a downstream gene, designated pdt, which encodes a prephenate dehydratase (PDT) enzyme involved in phenylalanine biosynthesis. Deletion of pdt significantly impaired the ability of UAMS-1 to grow in chemically-defined media lacking phenylalanine, confirming the function of this enzyme. Bioinformatics analysis revealed that the operon organization of nos-pdt appears to be unique to the staphylococci. As described for other S. aureus nos mutants, inactivation of nos in UAMS-1 conferred sensitivity to oxidative stress, while deletion of pdt did not affect this phenotype. The nos mutant also displayed reduced virulence in a murine sepsis infection model, and increased carotenoid pigmentation when cultured on agar plates, both previously-undescribed nos mutant phenotypes. Utilizing the fluorescent stain 4-Amino-5-Methylamino-2',7'-Difluorofluorescein (DAF-FM) diacetate, decreased levels of intracellular NO/reactive nitrogen species (RNS) were detected in the nos mutant on agar plates. These results reinforce the important role of saNOS in S. aureus physiology and virulence, and have identified an in vitro growth condition under which saNOS activity appears to be upregulated. However, the significance of the operon organization of nos-pdt and potential relationship between these two enzymes remains to be elucidated. [Mh] Termos MeSH primário: Meticilina/farmacologia Óxido Nítrico Sintase/genética Óperon/genética Prefenato Desidratase/genética Staphylococcus aureus/genética Staphylococcus aureus/patogenicidade [Mh] Termos MeSH secundário: Animais Carotenoides/metabolismo Modelos Animais de Doenças Feminino Fluoresceínas/metabolismo Genes Bacterianos Espaço Intracelular/efeitos dos fármacos Espaço Intracelular/metabolismo Camundongos Óxido Nítrico/metabolismo Estresse Oxidativo/efeitos dos fármacos Fenótipo Fenilalanina/farmacologia Pigmentação/efeitos dos fármacos Espécies Reativas de Nitrogênio/metabolismo Sepse/microbiologia Sepse/patologia Staphylococcus aureus/efeitos dos fármacos Staphylococcus aureus/crescimento & desenvolvimento Análise de Sobrevida Transcrição Genética/efeitos dos fármacos Virulência/efeitos dos fármacos Virulência/genética [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Fluoresceins); 0 (Reactive Nitrogen Species); 2044-85-1 (diacetyldichlorofluorescein); 31C4KY9ESH (Nitric Oxide); 36-88-4 (Carotenoids); 47E5O17Y3R (Phenylalanine); EC 1.14.13.39 (Nitric Oxide Synthase); EC 4.2.1.51 (Prephenate Dehydratase); Q91FH1328A (Methicillin) [Em] Mês de entrada: 1506 [Cu] Atualização por classe: 170220 [Lr] Data última revisão: 170220 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 141003 [St] Status: MEDLINE [do] DOI: 10.1371/journal.pone.0108868

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[PMID]: 24610334 [Au] Autor: Shin MH; Ku HK; Song JS; Choi S; Son SY; Yang HJ; Kim HD; Kim SK; Park IY; Lee SJ [Ad] Endereço: College of Pharmacy, Chungbuk National University, Chungbuk, 361-763, Republic of Korea. [Ti] Título: X-ray structure of prephenate dehydratase from Streptococcus mutans. [So] Source: J Microbiol;52(6):490-5, 2014 Jun. [Is] ISSN: 1976-3794 [Cp] País de publicação: Korea (South) [La] Idioma: eng [Ab] Resumo: Prephenate dehydratase is a key enzyme of the biosynthesis of L-phenylalanine in the organisms that utilize shikimate pathway. Since this enzymatic pathway does not exist in mammals, prephenate dehydratase can provide a new drug targets for antibiotics or herbicide. Prephenate dehydratase is an allosteric enzyme regulated by its end product. The enzyme composed of two domains, catalytic PDT domain located near the N-terminal and regulatory ACT domain located near the C-terminal. The allosteric enzyme is suggested to have two different conformations. When the regulatory molecule, phenylalanine, is not bound to its ACT domain, the catalytic site of PDT domain maintain open (active) state conformation as Sa-PDT structure. And the open state of its catalytic site become closed (allosterically inhibited) state if the regulatory molecule is bound to its ACT domain as Ct-PDT structure. However, the X-ray structure of prephenate dehydratase from Streptococcus mutans (Sm-PDT) shows that the catalytic site of Sm-PDT has closed state conformation without phenylalanine molecule bound to its regulatory site. The structure suggests a possibility that the binding of phenylalanine in its regulatory site may not be the only prerequisite for the closed state conformation of Sm-PDT. [Mh] Termos MeSH primário: Prefenato Desidratase/química Streptococcus mutans/enzimologia [Mh] Termos MeSH secundário: Cristalografia por Raios X/métodos [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: EC 4.2.1.51 (Prephenate Dehydratase) [Em] Mês de entrada: 1502 [Cu] Atualização por classe: 171109 [Lr] Data última revisão: 171109 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 140311 [St] Status: MEDLINE [do] DOI: 10.1007/s12275-014-3645-8

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[PMID]: 23526182 [Au] Autor: Zhang C; Zhang J; Kang Z; Du G; Yu X; Wang T; Chen J [Ad] Endereço: The Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China. [Ti] Título: Enhanced production of L-phenylalanine in Corynebacterium glutamicum due to the introduction of Escherichia coli wild-type gene aroH. [So] Source: J Ind Microbiol Biotechnol;40(6):643-51, 2013 Jun. [Is] ISSN: 1476-5535 [Cp] País de publicação: Germany [La] Idioma: eng [Ab] Resumo: Metabolic engineering is a powerful tool which has been widely used for producing valuable products. For improving L-phenylalanine (L-Phe) accumulation in Corynebacterium glutamicum, we have investigated the target genes involved in the biosynthetic pathways. The genes involved in the biosynthesis of L-Phe were found to be strictly regulated genes by feedback inhibition. As a result, overexpression of the native wild-type genes aroF, aroG or pheA resulted in a slight increase of L-Phe. In contrast, overexpression of aroF (wt) or pheA (fbr) from E. coli significantly increased L-Phe production. Co-overexpression of aroF (wt) and pheA (fbr) improved the titer of L-Phe to 4.46 ± 0.06 g lâ�»¹. To further analyze the target enzymes in the aromatic amino acid synthesis pathway between C. glutamicum and E. coli, the wild-type gene aroH from E. coli was overexpressed and evaluated in C. glutamicum. As predicted, upregulation of the wild-type gene aroH resulted in a remarkable increase of L-Phe production. Co-overexpression of the mutated pheA (fbr) and the wild-type gene aroH resulted in the production of L-Phe up to 4.64 ± 0.09 g lâ�»¹. Based on these results we conclude that the wild-type gene aroH from E. coli is an appropriate target gene for pathway engineering in C. glutamicum for the production of aromatic amino acids. [Mh] Termos MeSH primário: Alquil e Aril Transferases/genética Vias Biossintéticas/genética Corynebacterium glutamicum/metabolismo Proteínas de Escherichia coli/genética Escherichia coli/enzimologia Escherichia coli/genética Fenilalanina/biossíntese [Mh] Termos MeSH secundário: Alquil e Aril Transferases/metabolismo Corynebacterium glutamicum/genética Proteínas de Escherichia coli/metabolismo Retroalimentação Fisiológica Expressão Gênica Engenharia Metabólica Complexos Multienzimáticos/genética Complexos Multienzimáticos/metabolismo Prefenato Desidratase/genética Prefenato Desidratase/metabolismo [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Escherichia coli Proteins); 0 (Multienzyme Complexes); 0 (P-protein, E coli); 47E5O17Y3R (Phenylalanine); EC 2.5.- (Alkyl and Aryl Transferases); EC 2.5.- (aroH protein, E coli); EC 4.2.1.51 (Prephenate Dehydratase) [Em] Mês de entrada: 1404 [Cu] Atualização por classe: 171014 [Lr] Data última revisão: 171014 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 130326 [St] Status: MEDLINE [do] DOI: 10.1007/s10295-013-1262-x

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