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  1 / 101 MEDLINE  
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[PMID]:28750065
[Au] Autor:Zapata-Pérez R; Martínez-Moñino AB; García-Saura AG; Cabanes J; Takami H; Sánchez-Ferrer Á
[Ad] Endereço:Department of Biochemistry and Molecular Biology-A, Faculty of Biology, Regional Campus of International Excellence "Campus Mare Nostrum", University of Murcia, Murcia, Spain.
[Ti] Título:Biochemical characterization of a new nicotinamidase from an unclassified bacterium thriving in a geothermal water stream microbial mat community.
[So] Source:PLoS One;12(7):e0181561, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Nicotinamidases are amidohydrolases that convert nicotinamide into nicotinic acid, contributing to NAD+ homeostasis in most organisms. In order to increase the number of nicotinamidases described to date, this manuscript characterizes a nicotinamidase obtained from a metagenomic library fosmid clone (JFF054_F02) obtained from a geothermal water stream microbial mat community in a Japanese epithermal mine. The enzyme showed an optimum temperature of 90°C, making it the first hyperthermophilic bacterial nicotinamidase to be characterized, since the phylogenetic analysis of this fosmid clone placed it in a clade of uncultured geothermal bacteria. The enzyme, named as UbNic, not only showed an alkaline optimum pH, but also a biphasic pH dependence of its kcat, with a maximum at pH 9.5-10.0. The two pKa values obtained were 4.2 and 8.6 for pKes1 and pKes2, respectively. These results suggest a possible flexible catalytic mechanism for nicotinamidases, which reconciles the two previously proposed mechanisms. In addition, the enzyme showed a high catalytic efficiency, not only toward nicotinamide, but also toward other nicotinamide analogs. Its mutational analysis showed that a tryptophan (W83) is needed in one of the faces of the active site to maintain low Km values toward all the substrates tested. Furthermore, UbNic proved to contain a Fe2+ ion in its metal binding site, and was revealed to belong to a new nicotinamidase subgroup. All these characteristics, together with its high pH- and thermal stability, distinguish UbNic from previously described nicotinamidases, and suggest that a wide diversity of enzymes remains to be discovered in extreme environments.
[Mh] Termos MeSH primário: Bactérias/enzimologia
Fontes Termais/microbiologia
Microbiota
Nicotinamidase/metabolismo
Rios/microbiologia
Microbiologia da Água
[Mh] Termos MeSH secundário: Aldeídos/metabolismo
Sequência de Aminoácidos
Inibidores Enzimáticos/farmacologia
Estabilidade Enzimática/efeitos dos fármacos
Concentração de Íons de Hidrogênio
Cinética
Modelos Moleculares
Proteínas Mutantes/metabolismo
Nicotinamidase/antagonistas & inibidores
Nicotinamidase/química
Filogenia
Alinhamento de Sequência
Homologia de Sequência de Aminoácidos
Especificidade por Substrato
Temperatura Ambiente
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Aldehydes); 0 (Enzyme Inhibitors); 0 (Mutant Proteins); 840R4IDQ1T (3-pyridinaldehyde); EC 3.5.1.19 (Nicotinamidase)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170929
[Lr] Data última revisão:
170929
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170728
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0181561


  2 / 101 MEDLINE  
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[PMID]:28630126
[Au] Autor:Taniguchi H; Sungwallek S; Chotchuang P; Okano K; Honda K
[Ad] Endereço:Synthetic Bioengineering Lab, Department of Biotechnology, Graduate School of Engineering, Osaka University, Osaka, Japan.
[Ti] Título:A Key Enzyme of the NAD Salvage Pathway in Thermus thermophilus: Characterization of Nicotinamidase and the Impact of Its Gene Deletion at High Temperatures.
[So] Source:J Bacteriol;199(17), 2017 Sep 01.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:NAD (NAD ) is a cofactor related to many cellular processes. This cofactor is known to be unstable, especially at high temperatures, where it chemically decomposes to nicotinamide and ADP-ribose. Bacteria, yeast, and higher organisms possess the salvage pathway for reconstructing NAD from these decomposition products; however, the importance of the salvage pathway for survival is not well elucidated, except for in pathogens lacking the NAD synthesis pathway. Herein, we report the importance of the NAD salvage pathway in the thermophilic bacterium HB8 at high temperatures. We identified the gene encoding nicotinamidase (TTHA0328), which catalyzes the first reaction of the NAD salvage pathway. This recombinant enzyme has a high catalytic activity against nicotinamide ( of 17 µM, of 50 s , / of 3.0 × 10 s · mM ). Deletion of this gene abolished nicotinamide deamination activity in crude extracts of and disrupted the NAD salvage pathway in Disruption of the salvage pathway led to the severe growth retardation at a higher temperature (80°C), owing to the drastic decrease in the intracellular concentrations of NAD and NADH. NAD and other nicotinamide cofactors are essential for cell metabolism. These molecules are unstable and decompose, even under the physiological conditions in most organisms. Thermophiles can survive at high temperatures where NAD decomposition is, in general, more rapid. This study emphasizes that NAD instability and its homeostasis can be one of the important factors for thermophile survival in extreme temperatures.
[Mh] Termos MeSH primário: Deleção de Genes
NAD/metabolismo
Nicotinamidase/metabolismo
Thermus thermophilus/enzimologia
Thermus thermophilus/efeitos da radiação
[Mh] Termos MeSH secundário: Temperatura Alta
Cinética
Niacinamida/metabolismo
Nicotinamidase/genética
Thermus thermophilus/genética
Thermus thermophilus/crescimento & desenvolvimento
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0U46U6E8UK (NAD); 25X51I8RD4 (Niacinamide); EC 3.5.1.19 (Nicotinamidase)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170827
[Lr] Data última revisão:
170827
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170621
[St] Status:MEDLINE


  3 / 101 MEDLINE  
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[PMID]:27799288
[Au] Autor:Molina-Serrano D; Schiza V; Demosthenous C; Stavrou E; Oppelt J; Kyriakou D; Liu W; Zisser G; Bergler H; Dang W; Kirmizis A
[Ad] Endereço:Department of Biological Sciences, University of Cyprus, Nicosia, Cyprus.
[Ti] Título:Loss of Nat4 and its associated histone H4 N-terminal acetylation mediates calorie restriction-induced longevity.
[So] Source:EMBO Rep;17(12):1829-1843, 2016 Dec.
[Is] ISSN:1469-3178
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Changes in histone modifications are an attractive model through which environmental signals, such as diet, could be integrated in the cell for regulating its lifespan. However, evidence linking dietary interventions with specific alterations in histone modifications that subsequently affect lifespan remains elusive. We show here that deletion of histone N-alpha-terminal acetyltransferase Nat4 and loss of its associated H4 N-terminal acetylation (N-acH4) extend yeast replicative lifespan. Notably, nat4Δ-induced longevity is epistatic to the effects of calorie restriction (CR). Consistent with this, (i) Nat4 expression is downregulated and the levels of N-acH4 within chromatin are reduced upon CR, (ii) constitutive expression of Nat4 and maintenance of N-acH4 levels reduces the extension of lifespan mediated by CR, and (iii) transcriptome analysis indicates that nat4Δ largely mimics the effects of CR, especially in the induction of stress-response genes. We further show that nicotinamidase Pnc1, which is typically upregulated under CR, is required for nat4Δ-mediated longevity. Collectively, these findings establish histone N-acH4 as a regulator of cellular lifespan that links CR to increased stress resistance and longevity.
[Mh] Termos MeSH primário: Restrição Calórica
Regulação Fúngica da Expressão Gênica
Histonas/metabolismo
Acetiltransferase N-Terminal D/deficiência
Acetiltransferase N-Terminal D/fisiologia
Proteínas de Saccharomyces cerevisiae/fisiologia
Saccharomyces cerevisiae/fisiologia
[Mh] Termos MeSH secundário: Acetilação
Cromatina/metabolismo
Regulação para Baixo
Perfilação da Expressão Gênica
Histona Acetiltransferases/metabolismo
Longevidade
Acetiltransferase N-Terminal D/genética
Nicotinamidase/genética
Nicotinamidase/metabolismo
Processamento de Proteína Pós-Traducional
Saccharomyces cerevisiae/genética
Proteínas de Saccharomyces cerevisiae/genética
Proteínas de Saccharomyces cerevisiae/metabolismo
Fatores de Tempo
Ativação Transcricional
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Chromatin); 0 (Histones); 0 (Saccharomyces cerevisiae Proteins); EC 2.3.1.48 (Histone Acetyltransferases); EC 2.3.1.88 (N-Terminal Acetyltransferase D); EC 2.3.1.88 (NAT4 protein, S cerevisiae); EC 3.5.1.19 (Nicotinamidase); EC 3.5.1.19 (PNC1 protein, S cerevisiae)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161102
[St] Status:MEDLINE


  4 / 101 MEDLINE  
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[PMID]:27527516
[Au] Autor:Rössl A; Bentley-DeSousa A; Tseng YC; Nwosu C; Downey M
[Ad] Endereço:Department of Cellular and Molecular Medicine, University of Ottawa, Ontario K1H 8M5, Canada Ottawa Institute of Systems Biology, University of Ottawa, Ontario K1H 8M5, Canada.
[Ti] Título:Nicotinamide Suppresses the DNA Damage Sensitivity of Saccharomyces cerevisiae Independently of Sirtuin Deacetylases.
[So] Source:Genetics;204(2):569-579, 2016 Oct.
[Is] ISSN:1943-2631
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Nicotinamide is both a reaction product and an inhibitor of the conserved sirtuin family of deacetylases, which have been implicated in a broad range of cellular functions in eukaryotes from yeast to humans. Phenotypes observed following treatment with nicotinamide are most often assumed to stem from inhibition of one or more of these enzymes. Here, we used this small molecule to inhibit multiple sirtuins at once during treatment with DNA damaging agents in the Saccharomyces cerevisiae model system. Since sirtuins have been previously implicated in the DNA damage response, we were surprised to observe that nicotinamide actually increased the survival of yeast cells exposed to the DNA damage agent MMS. Remarkably, we found that enhanced resistance to MMS in the presence of nicotinamide was independent of all five yeast sirtuins. Enhanced resistance was also independent of the nicotinamide salvage pathway, which uses nicotinamide as a substrate to generate NAD+, and of a DNA damage-induced increase in the salvage enzyme Pnc1 Our data suggest a novel and unexpected function for nicotinamide that has broad implications for its use in the study of sirtuin biology across model systems.
[Mh] Termos MeSH primário: Dano ao DNA/genética
Histona Desacetilases do Grupo III/genética
Nicotinamidase/genética
Proteínas de Saccharomyces cerevisiae/genética
Sirtuínas/genética
[Mh] Termos MeSH secundário: Dano ao DNA/efeitos dos fármacos
Regulação Fúngica da Expressão Gênica/efeitos dos fármacos
Inativação Gênica
Histona Desacetilases do Grupo III/biossíntese
Metanossulfonato de Metila/toxicidade
Niacinamida/farmacologia
Fenótipo
Saccharomyces cerevisiae/efeitos dos fármacos
Saccharomyces cerevisiae/genética
Sirtuínas/biossíntese
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Saccharomyces cerevisiae Proteins); 25X51I8RD4 (Niacinamide); AT5C31J09G (Methyl Methanesulfonate); EC 3.5.1.- (Group III Histone Deacetylases); EC 3.5.1.- (Sirtuins); EC 3.5.1.19 (Nicotinamidase); EC 3.5.1.19 (PNC1 protein, S cerevisiae)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:171001
[Lr] Data última revisão:
171001
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160817
[St] Status:MEDLINE


  5 / 101 MEDLINE  
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[PMID]:27451449
[Au] Autor:Wang X; Liu B; Dou Y; Fan H; Wang S; Li T; Ding C; Yu S
[Ad] Endereço:Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China.
[Ti] Título:The Riemerella anatipestifer AS87_01735 Gene Encodes Nicotinamidase PncA, an Important Virulence Factor.
[So] Source:Appl Environ Microbiol;82(19):5815-23, 2016 Oct 01.
[Is] ISSN:1098-5336
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:UNLABELLED: Riemerella anatipestifer is a major bacterial pathogen that causes septicemic and exudative diseases in domestic ducks. In our previous study, we found that deletion of the AS87_01735 gene significantly decreased the bacterial virulence of R. anatipestifer strain Yb2 (mutant RA625). The AS87_01735 gene was predicted to encode a nicotinamidase (PncA), a key enzyme that catalyzes the conversion of nicotinamide to nicotinic acid, which is an important reaction in the NAD(+) salvage pathway. In this study, the AS87_01735 gene was expressed and identified as the PncA-encoding gene, using an enzymatic assay. Western blot analysis demonstrated that R. anatipestifer PncA was localized to the cytoplasm. The mutant strain RA625 (named Yb2ΔpncA in this study) showed a similar growth rate but decreased NAD(+) quantities in both the exponential and stationary phases in tryptic soy broth culture, compared with the wild-type strain Yb2. In addition, Yb2ΔpncA-infected ducks showed much lower bacterial loads in their blood, and no visible histological changes were observed in the heart, liver, and spleen. Furthermore, Yb2ΔpncA immunization of ducks conferred effective protection against challenge with the virulent wild-type strain Yb2. Our results suggest that the R. anatipestifer AS87_01735 gene encodes PncA, which is an important virulence factor, and that the Yb2ΔpncA mutant can be used as a novel live vaccine candidate. IMPORTANCE: Riemerella anatipestifer is reported worldwide as a cause of septicemic and exudative diseases of domestic ducks. The pncA gene encodes a nicotinamidase (PncA), a key enzyme that catalyzes the conversion of nicotinamide to nicotinic acid, which is an important reaction in the NAD(+) salvage pathway. In this study, we identified and characterized the pncA-homologous gene AS87_01735 in R. anatipestifer strain Yb2. R. anatipestifer PncA is a cytoplasmic protein that possesses similar PncA activity, compared with other organisms. Generation of the pncA mutant Yb2ΔpncA led to a decrease in the NAD(+) content, which was associated with decreased capacity for invasion and attenuated virulence in ducks. Furthermore, Yb2ΔpncA immunization of ducks conferred effective protection against challenge with the virulent wild-type strain Yb2. Altogether, these results suggest that PncA contributes to the virulence of R. anatipestifer and that the Yb2ΔpncA mutant can be used as a novel live vaccine candidate.
[Mh] Termos MeSH primário: Proteínas de Bactérias/genética
Patos
Infecções por Flavobacteriaceae/veterinária
Nicotinamidase/genética
Doenças das Aves Domésticas/imunologia
Riemerella/genética
Fatores de Virulência/genética
[Mh] Termos MeSH secundário: Animais
Proteínas de Bactérias/imunologia
Proteínas de Bactérias/metabolismo
Vacinas Bacterianas/imunologia
Vacinas Bacterianas/microbiologia
Infecções por Flavobacteriaceae/imunologia
Infecções por Flavobacteriaceae/microbiologia
Expressão Gênica
Imunização/veterinária
Nicotinamidase/imunologia
Nicotinamidase/metabolismo
Doenças das Aves Domésticas/microbiologia
Riemerella/imunologia
Riemerella/metabolismo
Deleção de Sequência
Vacinas Atenuadas/imunologia
Fatores de Virulência/imunologia
Fatores de Virulência/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Bacterial Vaccines); 0 (Vaccines, Attenuated); 0 (Virulence Factors); EC 3.5.1.19 (Nicotinamidase)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171106
[Lr] Data última revisão:
171106
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160725
[St] Status:MEDLINE
[do] DOI:10.1128/AEM.01829-16


  6 / 101 MEDLINE  
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[PMID]:26516056
[Au] Autor:Kumar S; Singh R; Williams CP; van der Klei IJ
[Ad] Endereço:Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, P.O. Box 11103, 9700CC Groningen, The Netherlands. Electronic address: s.kumar@rug.nl.
[Ti] Título:Stress exposure results in increased peroxisomal levels of yeast Pnc1 and Gpd1, which are imported via a piggy-backing mechanism.
[So] Source:Biochim Biophys Acta;1863(1):148-56, 2016 Jan.
[Is] ISSN:0006-3002
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Saccharomyces cerevisiae glycerol phosphate dehydrogenase 1 (Gpd1) and nicotinamidase (Pnc1) are two stress-induced enzymes. Both enzymes are predominantly localised to peroxisomes at normal growth conditions, but were reported to localise to the cytosol and nucleus upon exposure of cells to stress. Import of both proteins into peroxisomes depends on the peroxisomal targeting signal 2 (PTS2) receptor Pex7. Gpd1 contains a PTS2, however, Pnc1 lacks this sequence. Here we show that Pnc1 physically interacts with Gpd1, which is required for piggy-back import of Pnc1 into peroxisomes. Quantitative fluorescence microscopy analyses revealed that the levels of both proteins increased in peroxisomes and in the cytosol upon exposure of cells to stress. However, upon exposure of cells to stress we also observed enhanced cytosolic levels of the control PTS2 protein thiolase, when produced under control of the GPD1 promoter. This suggests that these conditions cause a partial defect in PTS2 protein import, probably because the PTS2 import pathway is easily saturated.
[Mh] Termos MeSH primário: Glicerol-3-Fosfato Desidrogenase (NAD+)/metabolismo
Nicotinamidase/metabolismo
Peroxissomos/metabolismo
Receptores Citoplasmáticos e Nucleares/metabolismo
Proteínas de Saccharomyces cerevisiae/metabolismo
Saccharomyces cerevisiae/metabolismo
Estresse Fisiológico/fisiologia
[Mh] Termos MeSH secundário: Glicerol-3-Fosfato Desidrogenase (NAD+)/genética
Nicotinamidase/genética
Receptor 2 de Sinal de Orientação para Peroxissomos
Peroxissomos/genética
Transporte Proteico/fisiologia
Receptores Citoplasmáticos e Nucleares/genética
Saccharomyces cerevisiae/genética
Proteínas de Saccharomyces cerevisiae/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Peroxisomal Targeting Signal 2 Receptor); 0 (Receptors, Cytoplasmic and Nuclear); 0 (Saccharomyces cerevisiae Proteins); EC 1.1.1.8 (GPD1 protein, S cerevisiae); EC 1.1.1.8 (Glycerol-3-Phosphate Dehydrogenase (NAD+)); EC 3.5.1.19 (Nicotinamidase); EC 3.5.1.19 (PNC1 protein, S cerevisiae)
[Em] Mês de entrada:1604
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151031
[St] Status:MEDLINE


  7 / 101 MEDLINE  
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[PMID]:26276932
[Au] Autor:Effelsberg D; Cruz-Zaragoza LD; Tonillo J; Schliebs W; Erdmann R
[Ad] Endereço:From the Institut für Biochemie und Pathobiochemie, Abteilung Systembiochemie, and.
[Ti] Título:Role of Pex21p for Piggyback Import of Gpd1p and Pnc1p into Peroxisomes of Saccharomyces cerevisiae.
[So] Source:J Biol Chem;290(42):25333-42, 2015 Oct 16.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Proteins designated for peroxisomal protein import harbor one of two common peroxisomal targeting signals (PTS). In the yeast Saccharomyces cerevisiae, the oleate-induced PTS2-dependent import of the thiolase Fox3p into peroxisomes is conducted by the soluble import receptor Pex7p in cooperation with the auxiliary Pex18p, one of two supposedly redundant PTS2 co-receptors. Here, we report on a novel function for the co-receptor Pex21p, which cannot be fulfilled by Pex18p. The data establish Pex21p as a general co-receptor in PTS2-dependent protein import, whereas Pex18p is especially important for oleate-induced import of PTS2 proteins. The glycerol-producing PTS2 protein glycerol-3-phosphate dehydrogenase Gpd1p shows a tripartite localization in peroxisomes, in the cytosol, and in the nucleus under osmotic stress conditions. We show the following: (i) Pex21p is required for peroxisomal import of Gpd1p as well as a key enzyme of the NAD(+) salvage pathway, Pnc1p; (ii) Pnc1p, a nicotinamidase without functional PTS2, is co-imported into peroxisomes by piggyback transport via Gpd1p. Moreover, the specific transport of these two enzymes into peroxisomes suggests a novel regulatory role for peroxisomes under various stress conditions.
[Mh] Termos MeSH primário: Proteínas de Transporte/fisiologia
Glicerol-3-Fosfato Desidrogenase (NAD+)/metabolismo
Nicotinamidase/metabolismo
Peroxissomos/metabolismo
Proteínas de Saccharomyces cerevisiae/metabolismo
Proteínas de Saccharomyces cerevisiae/fisiologia
Saccharomyces cerevisiae/metabolismo
[Mh] Termos MeSH secundário: Dimerização
Transporte Proteico
Saccharomyces cerevisiae/fisiologia
Estresse Fisiológico
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Carrier Proteins); 0 (PEX21 protein, S cerevisiae); 0 (Saccharomyces cerevisiae Proteins); EC 1.1.1.8 (GPD1 protein, S cerevisiae); EC 1.1.1.8 (Glycerol-3-Phosphate Dehydrogenase (NAD+)); EC 3.5.1.19 (Nicotinamidase); EC 3.5.1.19 (PNC1 protein, S cerevisiae)
[Em] Mês de entrada:1602
[Cu] Atualização por classe:161019
[Lr] Data última revisão:
161019
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150816
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M115.653451


  8 / 101 MEDLINE  
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[PMID]:25268724
[Au] Autor:Ion BF; Kazim E; Gauld JW
[Ad] Endereço:Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada.
[Ti] Título:A multi-scale computational study on the mechanism of Streptococcus pneumoniae Nicotinamidase (SpNic).
[So] Source:Molecules;19(10):15735-53, 2014 Sep 29.
[Is] ISSN:1420-3049
[Cp] País de publicação:Switzerland
[La] Idioma:eng
[Ab] Resumo:Nicotinamidase (Nic) is a key zinc-dependent enzyme in NAD metabolism that catalyzes the hydrolysis of nicotinamide to give nicotinic acid. A multi-scale computational approach has been used to investigate the catalytic mechanism, substrate binding and roles of active site residues of Nic from Streptococcus pneumoniae (SpNic). In particular, density functional theory (DFT), molecular dynamics (MD) and ONIOM quantum mechanics/molecular mechanics (QM/MM) methods have been employed. The overall mechanism occurs in two stages: (i) formation of a thioester enzyme-intermediate (IC2) and (ii) hydrolysis of the thioester bond to give the products. The polar protein environment has a significant effect in stabilizing reaction intermediates and in particular transition states. As a result, both stages effectively occur in one step with Stage 1, formation of IC2, being rate limiting barrier with a cost of 53.5 kJ·mol-1 with respect to the reactant complex, RC. The effects of dispersion interactions on the overall mechanism were also considered but were generally calculated to have less significant effects with the overall mechanism being unchanged. In addition, the active site lysyl (Lys103) is concluded to likely play a role in stabilizing the thiolate of Cys136 during the reaction.
[Mh] Termos MeSH primário: Modelos Químicos
Modelos Moleculares
Nicotinamidase/química
Nicotinamidase/metabolismo
Streptococcus pneumoniae/enzimologia
[Mh] Termos MeSH secundário: Sítios de Ligação
Catálise
Domínio Catalítico
Ligação Proteica
Conformação Proteica
Especificidade por Substrato
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
EC 3.5.1.19 (Nicotinamidase)
[Em] Mês de entrada:1506
[Cu] Atualização por classe:141001
[Lr] Data última revisão:
141001
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:141001
[St] Status:MEDLINE
[do] DOI:10.3390/molecules191015735


  9 / 101 MEDLINE  
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[PMID]:25199451
[Au] Autor:Rueda D; Sheen P; Gilman RH; Bueno C; Santos M; Pando-Robles V; Batista CV; Zimic M
[Ad] Endereço:Unidad de Bioinformática y Biología Molecular, Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru.
[Ti] Título:Nicotinamidase/pyrazinamidase of Mycobacterium tuberculosis forms homo-dimers stabilized by disulfide bonds.
[So] Source:Tuberculosis (Edinb);94(6):644-8, 2014 Dec.
[Is] ISSN:1873-281X
[Cp] País de publicação:Scotland
[La] Idioma:eng
[Ab] Resumo:Recombinant wild-pyrazinamidase from H37Rv Mycobacterium tuberculosis was analyzed by gel electrophoresis under differential reducing conditions to evaluate its quaternary structure. PZAse was fractionated by size exclusion chromatography under non-reducing conditions. PZAse activity was measured and mass spectrometry analysis was performed to determine the identity of proteins by de novo sequencing and to determine the presence of disulfide bonds. This study confirmed that M. tuberculosis wild type PZAse was able to form homo-dimers in vitro. Homo-dimers showed a slightly lower specific PZAse activity compared to monomeric PZAse. PZAse dimers were dissociated into monomers in response to reducing conditions. Mass spectrometry analysis confirmed the existence of disulfide bonds (C72-C138 and C138-C138) stabilizing the quaternary structure of the PZAse homo-dimer.
[Mh] Termos MeSH primário: Amidoidrolases/metabolismo
Mycobacterium tuberculosis/enzimologia
Nicotinamidase/metabolismo
[Mh] Termos MeSH secundário: Sítios de Ligação
Cromatografia em Gel/métodos
Dissulfetos/metabolismo
Seres Humanos
Espectrometria de Massas/métodos
Modelos Moleculares
Mycobacterium tuberculosis/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Disulfides); EC 3.5.- (Amidohydrolases); EC 3.5.1.- (pyrazinamide deamidase); EC 3.5.1.19 (Nicotinamidase)
[Em] Mês de entrada:1508
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140910
[St] Status:MEDLINE


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[PMID]:25188219
[Au] Autor:Mei SC; Brenner C
[Ad] Endereço:Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America.
[Ti] Título:Quantification of protein copy number in yeast: the NAD+ metabolome.
[So] Source:PLoS One;9(9):e106496, 2014.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Saccharomyces cerevisiae is calorie-restricted by lowering glucose from 2% to 0.5%. Under low glucose conditions, replicative lifespan is extended in a manner that depends on the NAD+-dependent protein lysine deacetylase Sir2 and NAD+ salvage enzymes. Because NAD+ is required for glucose utilization and Sir2 function, it was postulated that glucose levels alter the levels of NAD+ metabolites that tune Sir2 function. Though NAD+ precursor vitamins, which increase the levels of all NAD+ metabolites, can extend yeast replicative lifespan, glucose restriction does not significantly change the levels or ratios of intracellular NAD+ metabolites. To test whether glucose restriction affects protein copy numbers, we developed a technology that combines the measurement of Urh1 specific activity and quantification of relative expression between Urh1 and any other protein. The technology was applied to obtain the protein copy numbers of enzymes involved in NAD+ metabolism in rich and synthetic yeast media. Our data indicated that Sir2 and Pnc1, two enzymes that sequentially convert NAD+ to nicotinamide and then to nicotinic acid, are up-regulated by glucose restriction in rich media, and that Pnc1 alone is up-regulated in synthetic media while levels of all other enzymes are unchanged. These data suggest that production or export of nicotinic acid might be a connection between NAD+ and calorie restriction-mediated lifespan extension in yeast.
[Mh] Termos MeSH primário: Metaboloma
NAD/metabolismo
Saccharomyces cerevisiae/metabolismo
[Mh] Termos MeSH secundário: Niacina/metabolismo
Niacinamida/metabolismo
Nicotinamidase/metabolismo
Proteínas de Saccharomyces cerevisiae/metabolismo
Proteínas Reguladoras de Informação Silenciosa de Saccharomyces cerevisiae/metabolismo
Sirtuína 2/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Saccharomyces cerevisiae Proteins); 0 (Silent Information Regulator Proteins, Saccharomyces cerevisiae); 0U46U6E8UK (NAD); 25X51I8RD4 (Niacinamide); 2679MF687A (Niacin); EC 3.5.1.- (SIR2 protein, S cerevisiae); EC 3.5.1.- (Sirtuin 2); EC 3.5.1.19 (Nicotinamidase); EC 3.5.1.19 (PNC1 protein, S cerevisiae)
[Em] Mês de entrada:1505
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140905
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0106496



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