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Pesquisa : D08.811.913.696.630 [Categoria DeCS]
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[PMID]:28341883
[Au] Autor:Yang X
[Ad] Endereço:Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, 510006, People's Republic of China. birxyang@scut.edu.cn.
[Ti] Título:Conformational dynamics play important roles upon the function of N-acetylglutamate kinase.
[So] Source:Appl Microbiol Biotechnol;101(9):3485-3492, 2017 May.
[Is] ISSN:1432-0614
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:N-acetylglutamate kinase (NAGK) catalyzes the phosphorylation of N-acetylglutamate. In many bacteria, NAGK catalysis is the rate controlling step in the L-arginine biosynthesis pathway from glutamate to L-arginine and is allosterically inhibited by L-arginine. Many data show that conformational dynamics of NAGKs are essential for their function. The demonstration of the conformational mechanism provides a potential way to improve the yield of arginine. Due to the lack of NAGK catalysis step in arginine synthesis route of mammals, the elucidation of the dynamic mechanism can also provide a way to design a new antivirus drug. This paper reviews how the dynamics affect the activity of NAGKs and are controlled by the effectors. X-ray crystallography and modeling data have shown that in NAGKs, the structural elements required for inhibitor and substrate binding, catalysis and product release, are highly mobile. It is possible to eliminate the inhibition of the arginine and/or block the synthesis of arginine by disturbing the flexibility of the NAGKs. Amino acid kinase family is thought to share some common dynamic features; the flexible structural elements of NAGKs have been identified, but the details of the dynamics and the signal transfer pathways are yet to be elucidated.
[Mh] Termos MeSH primário: Glutamatos/metabolismo
Fosfotransferases (Aceptor do Grupo Carboxila)/química
Fosfotransferases (Aceptor do Grupo Carboxila)/metabolismo
[Mh] Termos MeSH secundário: Regulação Alostérica
Bactérias/enzimologia
Cristalografia por Raios X
Modelos Moleculares
Fosforilação
Conformação Proteica
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Glutamates); EC 2.7.2.- (Phosphotransferases (Carboxyl Group Acceptor)); EC 2.7.2.8 (acetylglutamate kinase); MA61H539YZ (N-acetylglutamic acid)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170428
[Lr] Data última revisão:
170428
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170326
[St] Status:MEDLINE
[do] DOI:10.1007/s00253-017-8237-1


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[PMID]:28135072
[Au] Autor:Mori S; Nepal KK; Kelly GT; Sharma V; Simkhada D; Gowda V; Delgado D; Watanabe CM
[Ad] Endereço:Department of Chemistry, Texas A&M University , College Station, Texas 77843, United States.
[Ti] Título:Priming of Azabicycle Biosynthesis in the Azinomycin Class of Antitumor Agents.
[So] Source:Biochemistry;56(6):805-808, 2017 Feb 14.
[Is] ISSN:1520-4995
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The biosynthesis of the azabicyclic ring system of the azinomycin family of antitumor agents represents the "crown jewel" of the pathway and is a complex process involving at least 14 enzymatic steps. This study reports on the first biosynthetic step, the inroads, in the construction of the novel aziridino [1,2-a]pyrrolidine, azabicyclic core, allowing us to support a new mechanism for azabicycle formation.
[Mh] Termos MeSH primário: Aldeído Oxirredutases/metabolismo
Aminoácido N-Acetiltransferase/metabolismo
Antineoplásicos Alquilantes/metabolismo
Compostos Azabicíclicos/metabolismo
Proteínas de Bactérias/metabolismo
Desenho de Drogas
Fosfotransferases (Aceptor do Grupo Carboxila)/metabolismo
Pirrolidinas/metabolismo
[Mh] Termos MeSH secundário: Acetilcoenzima A/metabolismo
Acetilação
Aldeído Oxirredutases/genética
Aminoácido N-Acetiltransferase/genética
Antibióticos Antineoplásicos/química
Antibióticos Antineoplásicos/metabolismo
Antibióticos Antineoplásicos/farmacologia
Antineoplásicos Alquilantes/química
Antineoplásicos Alquilantes/farmacologia
Compostos Azabicíclicos/química
Compostos Azabicíclicos/farmacologia
Proteínas de Bactérias/genética
Biocatálise
Dipeptídeos/química
Dipeptídeos/metabolismo
Dipeptídeos/farmacologia
Técnicas de Inativação de Genes
Ácido Glutâmico/metabolismo
Estrutura Molecular
Mutação
Naftalenos/química
Naftalenos/metabolismo
Naftalenos/farmacologia
Peptídeos/química
Peptídeos/metabolismo
Peptídeos/farmacologia
Fosfotransferases (Aceptor do Grupo Carboxila)/genética
Pirrolidinas/química
Pirrolidinas/farmacologia
Proteínas Recombinantes/metabolismo
Streptomyces/enzimologia
Streptomyces/metabolismo
Especificidade por Substrato
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Antibiotics, Antineoplastic); 0 (Antineoplastic Agents, Alkylating); 0 (Azabicyclo Compounds); 0 (Bacterial Proteins); 0 (Dipeptides); 0 (Naphthalenes); 0 (Peptides); 0 (Pyrrolidines); 0 (Recombinant Proteins); 106486-76-4 (azinomycin B); 106486-77-5 (azinomycin A); 3KX376GY7L (Glutamic Acid); 72-89-9 (Acetyl Coenzyme A); EC 1.2.- (Aldehyde Oxidoreductases); EC 1.2.1.38 (N-acetyl-gamma-glutamyl-phosphate reductase); EC 2.3.1.1 (Amino-Acid N-Acetyltransferase); EC 2.7.2.- (Phosphotransferases (Carboxyl Group Acceptor)); EC 2.7.2.8 (acetylglutamate kinase)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170516
[Lr] Data última revisão:
170516
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170131
[St] Status:MEDLINE
[do] DOI:10.1021/acs.biochem.6b01108


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[PMID]:27940001
[Au] Autor:Sirobhushanam S; Galva C; Saunders LP; Sen S; Jayaswal R; Wilkinson BJ; Gatto C
[Ad] Endereço:School of Biological Sciences, Illinois State University, Normal, IL 61790, United States.
[Ti] Título:Utilization of multiple substrates by butyrate kinase from Listeria monocytogenes.
[So] Source:Biochim Biophys Acta;1862(3):283-290, 2017 03.
[Is] ISSN:0006-3002
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Listeria monocytogenes, the causative agent of listeriosis, can build up to dangerous levels in refrigerated foods potentially leading to expensive product recalls. An important aspect of the bacterium's growth at low temperatures is its ability to increase the branched-chain fatty acid anteiso C15:0 content of its membrane at lower growth temperatures, which imparts greater membrane fluidity. Mutants in the branched-chain α-keto dehydrogenase (bkd) complex are deficient in branched-chain fatty acids (BCFAs,) but these can be restored by feeding C4 and C5 branched-chain carboxylic acids (BCCAs). This suggests the presence of an alternate pathway for production of acyl CoA precursors for fatty acid biosynthesis. We hypothesize that the alternate pathway is composed of butyrate kinase (buk) and phosphotransbutyrylase (ptb) encoded in the bkd complex which produce acyl CoA products by their sequential action through the metabolism of carboxylic acids. We determined the steady state kinetics of recombinant His-tagged Buk using 11 different straight-chain and BCCA substrates in the acyl phosphate forming direction. Buk demonstrated highest catalytic efficiency with pentanoate as the substrate. Low product formation observed with acetate (C2) and hexanoate (C6) as the substrates indicates that Buk is not involved in either acetate metabolism or long chain carboxylic acid activation. We were also able to show that Buk catalysis occurs through a ternary complex intermediate. Additionally, Buk demonstrates a strong preference for BCCAs at low temperatures. These results indicate that Buk may be involved in the activation and assimilation of exogenous carboxylic acids for membrane fatty acid biosynthesis.
[Mh] Termos MeSH primário: Listeria monocytogenes/metabolismo
Fosfotransferases (Aceptor do Grupo Carboxila)/metabolismo
[Mh] Termos MeSH secundário: Acil Coenzima A/metabolismo
Ácidos Carboxílicos/metabolismo
Temperatura Baixa
Ácidos Graxos/metabolismo
Cinética
Lipogênese/fisiologia
Fluidez de Membrana/fisiologia
Fosfato Acetiltransferase/metabolismo
Especificidade por Substrato
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Acyl Coenzyme A); 0 (Carboxylic Acids); 0 (Fatty Acids); EC 2.3.1.8 (Phosphate Acetyltransferase); EC 2.7.2.- (Phosphotransferases (Carboxyl Group Acceptor)); EC 2.7.2.7 (butyrate kinase)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171019
[Lr] Data última revisão:
171019
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161213
[St] Status:MEDLINE


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[PMID]:27672730
[Au] Autor:Tsolmonbaatar A; Hashida K; Sugimoto Y; Watanabe D; Furukawa S; Takagi H
[Ad] Endereço:Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.
[Ti] Título:Isolation of baker's yeast mutants with proline accumulation that showed enhanced tolerance to baking-associated stresses.
[So] Source:Int J Food Microbiol;238:233-240, 2016 Dec 05.
[Is] ISSN:1879-3460
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:During bread-making processes, yeast cells are exposed to baking-associated stresses such as freeze-thaw, air-drying, and high-sucrose concentrations. Previously, we reported that self-cloning diploid baker's yeast strains that accumulate proline retained higher-level fermentation abilities in both frozen and sweet doughs than the wild-type strain. Although self-cloning yeasts do not have to be treated as genetically modified yeasts, the conventional methods for breeding baker's yeasts are more acceptable to consumers than the use of self-cloning yeasts. In this study, we isolated mutants resistant to the proline analogue azetidine-2-carboxylate (AZC) derived from diploid baker's yeast of Saccharomyces cerevisiae. Some of the mutants accumulated a greater amount of intracellular proline, and among them, 5 mutants showed higher cell viability than that observed in the parent wild-type strain under freezing or high-sucrose stress conditions. Two of them carried novel mutations in the PRO1 gene encoding the Pro247Ser or Glu415Lys variant of γ-glutamyl kinase (GK), which is a key enzyme in proline biosynthesis in S. cerevisiae. Interestingly, we found that these mutations resulted in AZC resistance of yeast cells and desensitization to proline feedback inhibition of GK, leading to intracellular proline accumulation. Moreover, baker's yeast cells expressing the PRO1 and PRO1 gene were more tolerant to freezing stress than cells expressing the wild-type PRO1 gene. The approach described here could be a practical method for the breeding of proline-accumulating baker's yeasts with higher tolerance to baking-associated stresses.
[Mh] Termos MeSH primário: Prolina/metabolismo
Saccharomyces cerevisiae/genética
Saccharomyces cerevisiae/metabolismo
[Mh] Termos MeSH secundário: Pão/microbiologia
Culinária
Fermentação
Congelamento
Temperatura Alta
Mutação
Fosfotransferases (Aceptor do Grupo Carboxila)/genética
Fosfotransferases (Aceptor do Grupo Carboxila)/metabolismo
Saccharomyces cerevisiae/química
Saccharomyces cerevisiae/isolamento & purificação
Proteínas de Saccharomyces cerevisiae/genética
Proteínas de Saccharomyces cerevisiae/metabolismo
Sacarose/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Saccharomyces cerevisiae Proteins); 57-50-1 (Sucrose); 9DLQ4CIU6V (Proline); EC 2.7.2.- (Phosphotransferases (Carboxyl Group Acceptor)); EC 2.7.2.11 (glutamate 5-kinase)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:170817
[Lr] Data última revisão:
170817
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160928
[St] Status:MEDLINE


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[PMID]:27501982
[Au] Autor:Kershner JP; Yu McLoughlin S; Kim J; Morgenthaler A; Ebmeier CC; Old WM; Copley SD
[Ad] Endereço:Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Boulder, Colorado, USA Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Boulder, Colorado, USA.
[Ti] Título:A Synonymous Mutation Upstream of the Gene Encoding a Weak-Link Enzyme Causes an Ultrasensitive Response in Growth Rate.
[So] Source:J Bacteriol;198(20):2853-63, 2016 Oct 15.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:UNLABELLED: When microbes are faced with an environmental challenge or opportunity, preexisting enzymes with promiscuous secondary activities can be recruited to provide newly important functions. Mutations that increase the efficiency of a new activity often compromise the original activity, resulting in an inefficient bifunctional enzyme. We have investigated the mechanisms by which growth of Escherichia coli can be improved when fitness is limited by such an enzyme, E383A ProA (ProA*). ProA* can serve the functions of both ProA (required for synthesis of proline) and ArgC (required for synthesis of arginine), albeit poorly. We identified four genetic changes that improve the growth rate by up to 6.2-fold. Two point mutations in the promoter of the proBA* operon increase expression of the entire operon. Massive amplification of a genomic segment around the proBA* operon also increases expression of the entire operon. Finally, a synonymous point mutation in the coding region of proB creates a new promoter for proA* This synonymous mutation increases the level of ProA* by 2-fold but increases the growth rate by 5-fold, an ultrasensitive response likely arising from competition between two substrates for the active site of the inefficient bifunctional ProA*. IMPORTANCE: The high-impact synonymous mutation we discovered in proB is remarkable for two reasons. First, most polar effects documented in the literature are detrimental. This finding demonstrates that polar effect mutations can have strongly beneficial effects, especially when an organism is facing a difficult environmental challenge for which it is poorly adapted. Furthermore, the consequence of the synonymous mutation in proB is a 2-fold increase in the level of ProA* but a disproportionately large 5.1-fold increase in growth rate. While ultrasensitive responses are often found in signaling networks and genetic circuits, an ultrasensitive response to an adaptive mutation has not been previously reported.
[Mh] Termos MeSH primário: Proteínas de Escherichia coli/genética
Escherichia coli/enzimologia
Escherichia coli/crescimento & desenvolvimento
Glutamato-5-Semialdeído Desidrogenase/genética
Fosfotransferases (Aceptor do Grupo Carboxila)/genética
[Mh] Termos MeSH secundário: Sequência de Bases
Escherichia coli/genética
Escherichia coli/metabolismo
Proteínas de Escherichia coli/metabolismo
Regulação Bacteriana da Expressão Gênica
Glutamato-5-Semialdeído Desidrogenase/metabolismo
Cinética
Dados de Sequência Molecular
Mutação de Sentido Incorreto
Óperon
Fosfotransferases (Aceptor do Grupo Carboxila)/metabolismo
Mutação Puntual
Regiões Promotoras Genéticas
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Escherichia coli Proteins); EC 1.2.1.41 (Glutamate-5-Semialdehyde Dehydrogenase); EC 1.2.1.41 (proA protein, E coli); EC 2.7.2.- (Phosphotransferases (Carboxyl Group Acceptor)); EC 2.7.2.11 (glutamate 5-kinase)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170629
[Lr] Data última revisão:
170629
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160810
[St] Status:MEDLINE
[do] DOI:10.1128/JB.00262-16


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[PMID]:27442630
[Au] Autor:Tatehashi Y; Watanabe D; Takagi H
[Ad] Endereço:Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Japan.
[Ti] Título:γ-Glutamyl kinase is involved in selective autophagy of ribosomes in Saccharomyces cerevisiae.
[So] Source:FEBS Lett;590(17):2906-14, 2016 Sep.
[Is] ISSN:1873-3468
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:γ-Glutamyl kinase (GK; the PRO1 gene product) is a key enzyme in the Saccharomyces cerevisiae proline biosynthesis pathway. Δpro1 cells are more sensitive to various stresses than wild-type cells, suggesting that GK has an alternative function independent of proline biosynthesis. We show that PRO1 genetically interacts with UBP3, which encodes ubiquitin-specific protease, and is required for selective autophagy of ribosomes (ribophagy). Interestingly, yeast cells with PRO1 deletion or expressing inactive GK display a defect for ribophagy but not for nonselective autophagy, indicating that GK activity is indispensable for ribophagy. Gene disruption analysis suggests that ribophagy is important for cell survival during nitrogen starvation.
[Mh] Termos MeSH primário: Autofagia/genética
Endopeptidases/metabolismo
Fosfotransferases (Aceptor do Grupo Carboxila)/metabolismo
Proteínas de Saccharomyces cerevisiae/metabolismo
Saccharomyces cerevisiae/genética
[Mh] Termos MeSH secundário: Vias Biossintéticas/genética
Endopeptidases/genética
Fosfotransferases (Aceptor do Grupo Carboxila)/genética
Prolina/biossíntese
Ribossomos/genética
Proteínas de Saccharomyces cerevisiae/genética
Inanição
Ubiquitina/metabolismo
[Pt] Tipo de publicação:LETTER
[Nm] Nome de substância:
0 (Saccharomyces cerevisiae Proteins); 0 (Ubiquitin); 9DLQ4CIU6V (Proline); EC 2.7.2.- (Phosphotransferases (Carboxyl Group Acceptor)); EC 2.7.2.11 (glutamate 5-kinase); EC 3.4.- (Endopeptidases); EC 3.4.99.- (UBP3 protein, S cerevisiae)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170505
[Lr] Data última revisão:
170505
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160722
[St] Status:MEDLINE
[do] DOI:10.1002/1873-3468.12318


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[PMID]:27320015
[Au] Autor:Sirobhushanam S; Galva C; Sen S; Wilkinson BJ; Gatto C
[Ad] Endereço:School of Biological Sciences, Illinois State University, Normal, IL 61790, USA.
[Ti] Título:Broad substrate specificity of phosphotransbutyrylase from Listeria monocytogenes: A potential participant in an alternative pathway for provision of acyl CoA precursors for fatty acid biosynthesis.
[So] Source:Biochim Biophys Acta;1861(9 Pt A):1102-1110, 2016 09.
[Is] ISSN:0006-3002
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Listeria monocytogenes, the causative organism of the serious food-borne disease listeriosis, has a membrane abundant in branched-chain fatty acids (BCFAs). BCFAs are normally biosynthesized from branched-chain amino acids via the activity of branched chain α-keto acid dehydrogenase (Bkd), and disruption of this pathway results in reduced BCFA content in the membrane. Short branched-chain carboxylic acids (BCCAs) added as media supplements result in incorporation of BCFAs arising from the supplemented BCCAs in the membrane of L. monocytogenes bkd mutant MOR401. High concentrations of the supplements also effect similar changes in the membrane of the wild type organism with intact bkd. Such carboxylic acids clearly act as fatty acid precursors, and there must be an alternative pathway resulting in the formation of their CoA thioester derivatives. Candidates for this are the enzymes phosphotransbutyrylase (Ptb) and butyrate kinase (Buk), the products of the first two genes of the bkd operon. Ptb from L. monocytogenes exhibited broad substrate specificity, a strong preference for branched-chain substrates, a lack of activity with acetyl CoA and hexanoyl CoA, and strict chain length preference (C3-C5). Ptb catalysis involved ternary complex formation. Additionally, Ptb could utilize unnatural branched-chain substrates such as 2-ethylbutyryl CoA, albeit with lower efficiency, consistent with a potential involvement of this enzyme in the conversion of the carboxylic acid additives into CoA primers for BCFA biosynthesis.
[Mh] Termos MeSH primário: 3-Metil-2-Oxobutanoato Desidrogenase (Lipoamida)/genética
Aminoácidos de Cadeia Ramificada/biossíntese
Ácidos Graxos/biossíntese
Fosfato Acetiltransferase/metabolismo
Fosfotransferases (Aceptor do Grupo Carboxila)/genética
[Mh] Termos MeSH secundário: 3-Metil-2-Oxobutanoato Desidrogenase (Lipoamida)/metabolismo
Acil Coenzima A/metabolismo
Aminoácidos de Cadeia Ramificada/metabolismo
Ácidos Graxos/metabolismo
Seres Humanos
Lipogênese/genética
Listeria monocytogenes/genética
Listeria monocytogenes/patogenicidade
Listeriose/genética
Listeriose/microbiologia
Listeriose/patologia
Redes e Vias Metabólicas
Fosfato Acetiltransferase/genética
Fosfotransferases (Aceptor do Grupo Carboxila)/metabolismo
Especificidade por Substrato
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Acyl Coenzyme A); 0 (Amino Acids, Branched-Chain); 0 (Fatty Acids); 5060-32-2 (hexanoyl-coenzyme A); EC 1.2.4.4 (3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)); EC 2.3.1.8 (Phosphate Acetyltransferase); EC 2.7.2.- (Phosphotransferases (Carboxyl Group Acceptor)); EC 2.7.2.7 (butyrate kinase)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170902
[Lr] Data última revisão:
170902
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160621
[St] Status:MEDLINE


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[PMID]:26521658
[Au] Autor:Zhao Q; Luo Y; Dou W; Zhang X; Zhang X; Zhang W; Xu M; Geng Y; Rao Z; Xu Z
[Ad] Endereço:School of Pharmaceutical Science, Jiangnan University, Wuxi, 214122, People's Republic of China.
[Ti] Título:Controlling the transcription levels of argGH redistributed L-arginine metabolic flux in N-acetylglutamate kinase and ArgR-deregulated Corynebacterium crenatum.
[So] Source:J Ind Microbiol Biotechnol;43(1):55-66, 2016 Jan.
[Is] ISSN:1476-5535
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Corynebacterium crenatum SYPA5-5, an L-arginine high-producer obtained through multiple mutation-screening steps, had been deregulated by the repression of ArgR that inhibits L-arginine biosynthesis at genetic level. Further study indicated that feedback inhibition of SYPA5-5 N-acetylglutamate kinase (CcNAGK) by L-arginine, as another rate-limiting step, could be deregulated by introducing point mutations. Here, we introduced two of the positive mutations (H268N or R209A) of CcNAGK into the chromosome of SYPA5-5, however, resulting in accumulation of large amounts of the intermediates (L-citrulline and L-ornithine) and decreased production of L-arginine. Genetic and enzymatic levels analysis involved in L-arginine biosynthetic pathway of recombinants SYPA5-5-NAGKH268N (H-7) and SYPA5-5-NAGKR209A (R-8) showed that the transcription levels of argGH decreased accompanied with the reduction of argininosuccinate synthase and argininosuccinase activities, respectively, which led to the metabolic obstacle from L-citrulline to L-arginine. Co-expression of argGH with exogenous plasmid in H-7 and R-8 removed this bottleneck and increased L-arginine productivity remarkably. Compared with SYPA5-5, fermentation period of H-7/pDXW-10-argGH (H-7-GH) reduced to 16 h; meanwhile, the L-arginine productivity improved about 63.6%. Fed-batch fermentation of H-7-GH in 10 L bioreactor produced 389.9 mM L-arginine with the productivity of 5.42 mM h(-1). These results indicated that controlling the transcription of argGH was a key factor for regulating the metabolic flux toward L-arginine biosynthesis after deregulating the repression of ArgR and feedback inhibition of CcNAGK, and therefore functioned as another regulatory mode for L-arginine production. Thus, deregulating all these three regulatory modes was a powerful strategy to construct L-arginine high-producing C. crenatum.
[Mh] Termos MeSH primário: Arginina/metabolismo
Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Corynebacterium/metabolismo
Análise do Fluxo Metabólico
Fosfotransferases (Aceptor do Grupo Carboxila)/metabolismo
Transcrição Genética
[Mh] Termos MeSH secundário: Arginina/biossíntese
Argininossuccinato Liase/metabolismo
Argininossuccinato Sintase/metabolismo
Vias Biossintéticas/genética
Citrulina/metabolismo
Corynebacterium/genética
Retroalimentação Fisiológica
Fermentação
Regulação Bacteriana da Expressão Gênica
Genes Bacterianos/genética
Ornitina/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 29VT07BGDA (Citrulline); 94ZLA3W45F (Arginine); E524N2IXA3 (Ornithine); EC 2.7.2.- (Phosphotransferases (Carboxyl Group Acceptor)); EC 2.7.2.8 (acetylglutamate kinase); EC 4.3.2.1 (Argininosuccinate Lyase); EC 6.3.4.5 (Argininosuccinate Synthase)
[Em] Mês de entrada:1609
[Cu] Atualização por classe:171014
[Lr] Data última revisão:
171014
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151103
[St] Status:MEDLINE
[do] DOI:10.1007/s10295-015-1692-8


  9 / 266 MEDLINE  
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[PMID]:26512006
[Au] Autor:Huang Y; Li C; Zhang H; Liang S; Han S; Lin Y; Yang X; Zheng S
[Ad] Endereço:Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, 510006, People's Republic of China.
[Ti] Título:Monomeric Corynebacterium glutamicum N-acetyl glutamate kinase maintains sensitivity to L-arginine but has a lower intrinsic catalytic activity.
[So] Source:Appl Microbiol Biotechnol;100(4):1789-98, 2016 Feb.
[Is] ISSN:1432-0614
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:N-acetyl glutamate kinase (NAGK) is a key enzyme in the synthesis of L-arginine, and L-arginine-sensitive NAGK typically has hexameric architecture. Defining the relationship between this architecture and L-arginine inhibition can provide a foundation to identify the key amino acids involved in the allosteric regulation network of L-arginine. In the present study, the key amino acids in the N-terminal helix (N-helix) of Corynebacterium glutamicum (Cg) NAGK required for hexamer formation were determined using structural homology modeling and site-directed mutagenesis. It was also verified that hexameric architecture is required for the positive cooperativity of inhibition by L-arginine and for efficient catalysis, but that it is not the determinant of inhibition by L-arginine. Monomeric mutants retained a similar sensitivity to L-arginine as the hexameric form, indicating that monomers contain an independent, sensitive signal transduction network of L-arginine to mediate allosteric regulation. Mutation studies of CgNAGKs also revealed that amino acid residues 18-23 of the N-helix are required for inhibition by L-arginine, and that E19 may be an essential amino acid influencing the apparent affinity of L-arginine. Collectively, these studies may illuminate the basic mechanism of metabolic homeostasis of C. glutamicum.
[Mh] Termos MeSH primário: Arginina/metabolismo
Corynebacterium glutamicum/enzimologia
Fosfotransferases (Aceptor do Grupo Carboxila)/metabolismo
[Mh] Termos MeSH secundário: Regulação Alostérica
Análise Mutacional de DNA
Mutagênese Sítio-Dirigida
Fosfotransferases (Aceptor do Grupo Carboxila)/genética
Multimerização Proteica
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
94ZLA3W45F (Arginine); EC 2.7.2.- (Phosphotransferases (Carboxyl Group Acceptor)); EC 2.7.2.8 (acetylglutamate kinase)
[Em] Mês de entrada:1610
[Cu] Atualização por classe:161230
[Lr] Data última revisão:
161230
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151030
[St] Status:MEDLINE
[do] DOI:10.1007/s00253-015-7065-4


  10 / 266 MEDLINE  
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[PMID]:26310620
[Au] Autor:Shaikh S; Aaqil H; Rizvi SM; Shakil S; Abuzenadah AM; Gupta P; Saxena S; Tiwari RK; Kumar A
[Ad] Endereço:Department of Biosciences, Integral University, Lucknow, 226026, India.
[Ti] Título:Comparative Inhibition Study of Compounds Identified in the Methanolic Extract of Apamarga Kshara Against Trichomonas vaginalis Carbamate Kinase (TvCK): An Enzoinformatics Approach.
[So] Source:Interdiscip Sci;8(4):357-365, 2016 Dec.
[Is] ISSN:1867-1462
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:In the present study, we have identified ten compounds, namely dodecanol acid, myristic acid, neophytadiene, palmitic acid, heptadecanoic acid, linoleic acid, elaidic acid, 3-7-dimethyl acid, stearic acid and methyl eicos acid, of the methanolic extract of Apamarga Kshara by GC-MS analysis. Apamarga Kshara has been reported to be active against cervical erosion. Major causal organism for cervical erosion is Trichomonas vaginalis. However, there is a paucity of information about the mechanism of action and inhibitory effect of the biologically active natural compounds presented in A. Kshara against this organism (T. vaginalis). Therefore, present investigation was conducted to observe possible interactions of these compounds on T. vaginalis carbamate kinase using molecular docking software 'AutoDock 4.2.' Identification of the amino acid residues crucial for the interaction between T. vaginalis carbamate kinase and these natural compounds is of due scientific interest. The study will aid in efficacious and safe clinical use of the above-mentioned compounds.
[Mh] Termos MeSH primário: Metanol/química
Fosfotransferases (Aceptor do Grupo Carboxila)/antagonistas & inibidores
Extratos Vegetais/química
Extratos Vegetais/farmacologia
Plantas Medicinais/química
Trichomonas vaginalis/enzimologia
[Mh] Termos MeSH secundário: Cromatografia Gasosa-Espectrometria de Massas
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Plant Extracts); EC 2.7.2.- (Phosphotransferases (Carboxyl Group Acceptor)); EC 2.7.2.2 (carbamate kinase); Y4S76JWI15 (Methanol)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170508
[Lr] Data última revisão:
170508
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150828
[St] Status:MEDLINE



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