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Pesquisa : G05.308.290 [Categoria DeCS]
Referências encontradas : 614 [refinar]
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[PMID]:28463103
[Au] Autor:Le TN; Wagner A; Albers SV
[Ad] Endereço:Molecular Biology of Archaea, Institute of Biology II - Microbiology, University of Freiburg, Schaenzlestrasse 1, 79104 Freiburg, Germany.
[Ti] Título:A conserved hexanucleotide motif is important in UV-inducible promoters in Sulfolobus acidocaldarius.
[So] Source:Microbiology;163(5):778-788, 2017 May.
[Is] ISSN:1465-2080
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Upon DNA damage, Sulfolobales exhibit a global gene regulatory response resulting in the expression of DNA transfer and repair proteins and the repression of the cell division machinery. Because the archaeal DNA damage response is still poorly understood, we investigated the promoters of the highly induced ups operon. Ups pili are involved in cellular aggregation and DNA exchange between cells. With LacS reporter gene assays we identified a conserved, non-palindromic hexanucleotide motif upstream of the ups core promoter elements to be essential for promoter activity. Substitution of this cis regulatory motif in the ups promoters resulted in abolishment of cellular aggregation and reduced DNA transfer. By screening the Sulfolobus acidocaldarius genome we identified a total of 214 genes harbouring the hexanucleotide motif in their respective promoter regions. Many of these genes were previously found to be regulated upon UV light treatment. Given the fact that the identified motif is conserved among S. acidocaldarius and Sulfolobus tokodaii promoters, we speculate that a common regulatory mechanism is present in these two species in response to DNA-damaging conditions.
[Mh] Termos MeSH primário: DNA Arqueal/efeitos da radiação
Regulação da Expressão Gênica em Archaea/efeitos da radiação
Motivos de Nucleotídeos/genética
Regiões Promotoras Genéticas/efeitos da radiação
Sulfolobus acidocaldarius/genética
Raios Ultravioleta
[Mh] Termos MeSH secundário: Dano ao DNA/genética
Dano ao DNA/efeitos da radiação
Reparo do DNA/genética
Reparo do DNA/efeitos da radiação
DNA Arqueal/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Archaeal)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:180221
[Lr] Data última revisão:
180221
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170503
[St] Status:MEDLINE
[do] DOI:10.1099/mic.0.000455


  2 / 614 MEDLINE  
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[PMID]:29284023
[Au] Autor:Kosugi N; Araki T; Fujita J; Tanaka S; Fujiwara T
[Ad] Endereço:Department of Science, Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka, Japan.
[Ti] Título:Growth phenotype analysis of heme synthetic enzymes in a halophilic archaeon, Haloferax volcanii.
[So] Source:PLoS One;12(12):e0189913, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Halophilic euryarchaea lack many of the genes necessary for the protoporphyrin-dependent heme biosynthesis pathway previously identified in animals and plants. Bioinformatic analysis suggested the presence of two heme biosynthetic processes, an Fe-coproporphyrinogen III (coproheme) decarboxylase (ChdC) pathway and an alternative heme biosynthesis (Ahb) pathway, in Haloferax volcanii. PitA is specific to the halophilic archaea and has a unique molecular structure in which the ChdC domain is joined to the antibiotics biosynthesis monooxygenase (ABM)-like domain by a histidine-rich linker sequence. The pitA gene deletion variant of H. volcanii showed a phenotype with a significant reduction of aerobic growth. Addition of a protoheme complemented the phenotype, supporting the assumption that PitA participates in the aerobic heme biosynthesis. Deletion of the ahbD gene caused a significant reduction of only anaerobic growth by denitrification or dimethylsulfoxide (DMSO) respiration, and the growth was also complemented by addition of a protoheme. The experimental results suggest that the two heme biosynthesis pathways are utilized selectively under aerobic and anaerobic conditions in H. volcanii. The molecular structure and physiological function of PitA are also discussed on the basis of the limited proteolysis and sequence analysis.
[Mh] Termos MeSH primário: Proteínas Arqueais/metabolismo
Haloferax volcanii/crescimento & desenvolvimento
Heme/metabolismo
[Mh] Termos MeSH secundário: Deleção de Genes
Regulação da Expressão Gênica em Archaea
Haloferax volcanii/enzimologia
Haloferax volcanii/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Archaeal Proteins); 42VZT0U6YR (Heme)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180215
[Lr] Data última revisão:
180215
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171229
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0189913


  3 / 614 MEDLINE  
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[PMID]:27771939
[Au] Autor:Hoffmann L; Schummer A; Reimann J; Haurat MF; Wilson AJ; Beeby M; Warscheid B; Albers SV
[Ad] Endereço:Molecular Biology of Archaea, Institute of Biology II, Faculty of Biology, Microbiology, University of Freiburg, Freiburg, Germany.
[Ti] Título:Expanding the archaellum regulatory network - the eukaryotic protein kinases ArnC and ArnD influence motility of Sulfolobus acidocaldarius.
[So] Source:Microbiologyopen;6(1), 2017 02.
[Is] ISSN:2045-8827
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Expression of the archaellum, the archaeal-type IV pilus-like rotating motility structure is upregulated under nutrient limitation. This is controlled by a network of regulators, called the archaellum regulatory network (arn). Several of the components of this network in Sulfolobus acidocaldarius can be phosphorylated, and the deletion of the phosphatase PP2A results in strongly increased motility during starvation, indicating a role for phosphorylation in the regulation of motility. Analysis of the motility of different protein kinase deletion strains revealed that deletion of saci_0965, saci_1181, and saci_1193 resulted in reduced motility, whereas the deletion of saci_1694 resulted in hypermotility. Here ArnC (Saci_1193) and ArnD (Saci_1694) are characterized. Purified ArnC and ArnD phosphorylate serine and threonine residues in the C-terminus of the repressor ArnB. arnC is upregulated in starvation medium, whereas arnD is constitutively expressed. However, while differences in the expression and levels of flaB were observed in the ΔarnD strain during growth under rich conditions, under nutrient limiting conditions the ΔarnC and ΔarnD strains showed no large differences in the expression levels of the archaellum or of the studied regulators. This suggests that next to the regulation via the archaellum regulatory network additional regulatory mechanisms of expression and/or activity of the archaellum exist.
[Mh] Termos MeSH primário: Proteínas Arqueais/metabolismo
Flagelos/metabolismo
Regulação da Expressão Gênica em Archaea
Proteínas Quinases/metabolismo
Sulfolobus acidocaldarius/metabolismo
[Mh] Termos MeSH secundário: Proteínas Arqueais/genética
Flagelos/genética
Deleção de Genes
Fosforilação
Domínios Proteicos
Proteínas Quinases/genética
Transdução de Sinais/fisiologia
Inanição
Sulfolobus acidocaldarius/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Archaeal Proteins); EC 2.7.- (Protein Kinases)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:180108
[Lr] Data última revisão:
180108
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161025
[St] Status:MEDLINE
[do] DOI:10.1002/mbo3.414


  4 / 614 MEDLINE  
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[PMID]:28973467
[Au] Autor:Martinez-Pastor M; Lancaster WA; Tonner PD; Adams MWW; Schmid AK
[Ad] Endereço:Department of Biology, Duke University, Durham, NC 27708, USA.
[Ti] Título:A transcription network of interlocking positive feedback loops maintains intracellular iron balance in archaea.
[So] Source:Nucleic Acids Res;45(17):9990-10001, 2017 Sep 29.
[Is] ISSN:1362-4962
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Iron is required for key metabolic processes but is toxic in excess. This circumstance forces organisms across the tree of life to tightly regulate iron homeostasis. In hypersaline lakes dominated by archaeal species, iron levels are extremely low and subject to environmental change; however, mechanisms regulating iron homeostasis in archaea remain unclear. In previous work, we demonstrated that two transcription factors (TFs), Idr1 and Idr2, collaboratively regulate aspects of iron homeostasis in the model species Halobacterium salinarum. Here we show that Idr1 and Idr2 are part of an extended regulatory network of four TFs of the bacterial DtxR family that maintains intracellular iron balance. We demonstrate that each TF directly regulates at least one of the other DtxR TFs at the level of transcription. Dynamical modeling revealed interlocking positive feedback loop architecture, which exhibits bistable or oscillatory network dynamics depending on iron availability. TF knockout mutant phenotypes are consistent with model predictions. Together, our results support that this network regulates iron homeostasis despite variation in extracellular iron levels, consistent with dynamical properties of interlocking feedback architecture in eukaryotes. These results suggest that archaea use bacterial-type TFs in a eukaryotic regulatory network topology to adapt to harsh environments.
[Mh] Termos MeSH primário: Proteínas Arqueais/genética
Retroalimentação Fisiológica
Regulação da Expressão Gênica em Archaea
Redes Reguladoras de Genes
Halobacterium salinarum/genética
Ferro/metabolismo
[Mh] Termos MeSH secundário: Proteínas Arqueais/metabolismo
Proteínas de Ligação a DNA/genética
Proteínas de Ligação a DNA/metabolismo
Halobacterium salinarum/metabolismo
Homeostase/genética
Mutação
Proteínas Repressoras/genética
Proteínas Repressoras/metabolismo
Transcrição Genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Archaeal Proteins); 0 (DNA-Binding Proteins); 0 (Repressor Proteins); E1UOL152H7 (Iron)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171017
[Lr] Data última revisão:
171017
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171004
[St] Status:MEDLINE
[do] DOI:10.1093/nar/gkx662


  5 / 614 MEDLINE  
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[PMID]:28911114
[Au] Autor:Liu T; Liu Z; Ye Q; Pan S; Wang X; Li Y; Peng W; Liang Y; She Q; Peng N
[Ad] Endereço:State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, P.R. China.
[Ti] Título:Coupling transcriptional activation of CRISPR-Cas system and DNA repair genes by Csa3a in Sulfolobus islandicus.
[So] Source:Nucleic Acids Res;45(15):8978-8992, 2017 Sep 06.
[Is] ISSN:1362-4962
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:CRISPR-Cas system provides the adaptive immunity against invading genetic elements in prokaryotes. Recently, we demonstrated that Csa3a regulator mediates spacer acquisition in Sulfolobus islandicus by activating the expression of Type I-A adaptation cas genes. However, links between the activation of spacer adaptation and CRISPR transcription/processing, and the requirement for DNA repair genes during spacer acquisition remained poorly understood. Here, we demonstrated that de novo spacer acquisition required Csa1, Cas1, Cas2 and Cas4 proteins of the Sulfolobus Type I-A system. Disruption of genes implicated in crRNA maturation or DNA interference led to a significant accumulation of acquired spacers, mainly derived from host genomic DNA. Transcriptome and proteome analyses showed that Csa3a activated expression of adaptation cas genes, CRISPR RNAs, and DNA repair genes, including herA helicase, nurA nuclease and DNA polymerase II genes. Importantly, Csa3a specifically bound the promoters of the above DNA repair genes, suggesting that they were directly activated by Csa3a for adaptation. The Csa3a regulator also specifically bound to the leader sequence to activate CRISPR transcription in vivo. Our data indicated that the Csa3a regulator couples transcriptional activation of the CRISPR-Cas system and DNA repair genes for spacer adaptation and efficient interference of invading genetic elements.
[Mh] Termos MeSH primário: Proteínas Arqueais/genética
Sistemas CRISPR-Cas
Reparo do DNA
DNA Arqueal/genética
Regulação da Expressão Gênica em Archaea
Sulfolobus/genética
Ativação Transcricional
[Mh] Termos MeSH secundário: Proteínas Arqueais/imunologia
Sequência de Bases
Proteínas Associadas a CRISPR/genética
Proteínas Associadas a CRISPR/imunologia
Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas
DNA Helicases/genética
DNA Helicases/imunologia
DNA Polimerase II/genética
DNA Polimerase II/imunologia
DNA Arqueal/imunologia
Endodesoxirribonucleases/genética
Endodesoxirribonucleases/imunologia
Chaperonas Moleculares/genética
Chaperonas Moleculares/imunologia
Regiões Promotoras Genéticas
Alinhamento de Sequência
Homologia de Sequência do Ácido Nucleico
Sulfolobus/imunologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Archaeal Proteins); 0 (CRISPR-Associated Proteins); 0 (DNA, Archaeal); 0 (Molecular Chaperones); EC 2.7.7.- (DNA Polymerase II); EC 3.1.- (Endodeoxyribonucleases); EC 3.6.4.- (DNA Helicases)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171012
[Lr] Data última revisão:
171012
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170916
[St] Status:MEDLINE
[do] DOI:10.1093/nar/gkx612


  6 / 614 MEDLINE  
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[PMID]:28705933
[Au] Autor:Nguyen DMN; Schut GJ; Zadvornyy OA; Tokmina-Lukaszewska M; Poudel S; Lipscomb GL; Adams LA; Dinsmore JT; Nixon WJ; Boyd ES; Bothner B; Peters JW; Adams MWW
[Ad] Endereço:From the Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602.
[Ti] Título:Two functionally distinct NADP -dependent ferredoxin oxidoreductases maintain the primary redox balance of .
[So] Source:J Biol Chem;292(35):14603-14616, 2017 Sep 01.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Electron bifurcation has recently gained acceptance as the third mechanism of energy conservation in which energy is conserved through the coupling of exergonic and endergonic reactions. A structure-based mechanism of bifurcation has been elucidated recently for the flavin-based enzyme NADH-dependent ferredoxin NADP oxidoreductase I (NfnI) from the hyperthermophillic archaeon NfnI is thought to be involved in maintaining the cellular redox balance, producing NADPH for biosynthesis by recycling the two other primary redox carriers, NADH and ferredoxin. The genome encodes an NfnI paralog termed NfnII, and the two are differentially expressed, depending on the growth conditions. In this study, we show that deletion of the genes encoding either NfnI or NfnII affects the cellular concentrations of NAD(P)H and particularly NADPH. This results in a moderate to severe growth phenotype in deletion mutants, demonstrating a key role for each enzyme in maintaining redox homeostasis. Despite their similarity in primary sequence and cofactor content, crystallographic, kinetic, and mass spectrometry analyses reveal that there are fundamental structural differences between the two enzymes, and NfnII does not catalyze the NfnI bifurcating reaction. Instead, it exhibits non-bifurcating ferredoxin NADP oxidoreductase-type activity. NfnII is therefore proposed to be a bifunctional enzyme and also to catalyze a bifurcating reaction, although its third substrate, in addition to ferredoxin and NADP(H), is as yet unknown.
[Mh] Termos MeSH primário: Proteínas Arqueais/metabolismo
Ferredoxina-NADP Redutase/metabolismo
Ferredoxinas/metabolismo
Regulação da Expressão Gênica em Archaea
Modelos Moleculares
NADP/metabolismo
Pyrococcus furiosus/enzimologia
[Mh] Termos MeSH secundário: Proteínas Arqueais/química
Proteínas Arqueais/genética
Proteínas Arqueais/isolamento & purificação
Biocatálise
Coenzimas/química
Coenzimas/metabolismo
Cristalografia por Raios X
Ferredoxina-NADP Redutase/química
Ferredoxina-NADP Redutase/genética
Ferredoxina-NADP Redutase/isolamento & purificação
Ferredoxinas/química
Deleção de Genes
Homeostase
Isoenzimas/química
Isoenzimas/genética
Isoenzimas/isolamento & purificação
Isoenzimas/metabolismo
NAD/química
NAD/metabolismo
NADP/química
Organismos Geneticamente Modificados
Oxirredução
Filogenia
Multimerização Proteica
Subunidades Proteicas/química
Subunidades Proteicas/genética
Subunidades Proteicas/isolamento & purificação
Subunidades Proteicas/metabolismo
Pyrococcus furiosus/genética
Pyrococcus furiosus/crescimento & desenvolvimento
Proteínas Recombinantes de Fusão/química
Proteínas Recombinantes de Fusão/isolamento & purificação
Proteínas Recombinantes de Fusão/metabolismo
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Archaeal Proteins); 0 (Coenzymes); 0 (Ferredoxins); 0 (Isoenzymes); 0 (Protein Subunits); 0 (Recombinant Fusion Proteins); 0U46U6E8UK (NAD); 53-59-8 (NADP); EC 1.18.1.2 (Ferredoxin-NADP Reductase)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170926
[Lr] Data última revisão:
170926
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170715
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M117.794172


  7 / 614 MEDLINE  
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[PMID]:28525600
[Au] Autor:Lai LB; Tanimoto A; Lai SM; Chen WY; Marathe IA; Westhof E; Wysocki VH; Gopalan V
[Ad] Endereço:Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA.
[Ti] Título:A novel double kink-turn module in euryarchaeal RNase P RNAs.
[So] Source:Nucleic Acids Res;45(12):7432-7440, 2017 Jul 07.
[Is] ISSN:1362-4962
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:RNase P is primarily responsible for the 5΄ maturation of transfer RNAs (tRNAs) in all domains of life. Archaeal RNase P is a ribonucleoprotein made up of one catalytic RNA and five protein cofactors including L7Ae, which is known to bind the kink-turn (K-turn), an RNA structural element that causes axial bending. However, the number and location of K-turns in archaeal RNase P RNAs (RPRs) are unclear. As part of an integrated approach, we used native mass spectrometry to assess the number of L7Ae copies that bound the RPR and site-specific hydroxyl radical-mediated footprinting to localize the K-turns. Mutagenesis of each of the putative K-turns singly or in combination decreased the number of bound L7Ae copies, and either eliminated or changed the L7Ae footprint on the mutant RPRs. In addition, our results support an unprecedented 'double K-turn' module in type A and type M archaeal RPR variants.
[Mh] Termos MeSH primário: Proteínas Arqueais/química
Regulação da Expressão Gênica em Archaea
Methanocaldococcus/enzimologia
Pyrococcus furiosus/enzimologia
RNA Arqueal/química
RNA de Transferência/química
Ribonuclease P/química
[Mh] Termos MeSH secundário: Proteínas Arqueais/genética
Proteínas Arqueais/metabolismo
Sequência de Bases
Radical Hidroxila/química
Radical Hidroxila/metabolismo
Isoenzimas/química
Isoenzimas/genética
Isoenzimas/metabolismo
Methanocaldococcus/genética
Mathanococcus/enzimologia
Mathanococcus/genética
Mutação
Conformação de Ácido Nucleico
Ligação Proteica
Pyrococcus furiosus/genética
Precursores de RNA
RNA Arqueal/genética
RNA Arqueal/metabolismo
RNA de Transferência/genética
RNA de Transferência/metabolismo
Ribonuclease P/genética
Ribonuclease P/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Archaeal Proteins); 0 (Isoenzymes); 0 (RNA Precursors); 0 (RNA, Archaeal); 3352-57-6 (Hydroxyl Radical); 9014-25-9 (RNA, Transfer); EC 3.1.26.5 (Ribonuclease P)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171017
[Lr] Data última revisão:
171017
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170520
[St] Status:MEDLINE
[do] DOI:10.1093/nar/gkx388


  8 / 614 MEDLINE  
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[PMID]:28295726
[Au] Autor:Lipscomb GL; Schut GJ; Scott RA; Adams MWW
[Ad] Endereço:Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA.
[Ti] Título:SurR is a master regulator of the primary electron flow pathways in the order Thermococcales.
[So] Source:Mol Microbiol;104(5):869-881, 2017 Jun.
[Is] ISSN:1365-2958
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The sulfur response regulator, SurR, is among a handful of known redox-active transcriptional regulators. First characterized from the hyperthermophile Pyrococcus furiosus, it is unique to the archaeal order Thermococcales. P. furiosus has two modes of electron disposal. Hydrogen gas is produced when the organism is grown in the absence of elemental sulfur (S ) and H S is produced when grown in its presence. Switching between these metabolic modes requires a rapid transcriptional response and this is orchestrated by SurR. We show here that deletion of SurR causes severely impaired growth in the absence of S since genes essential for H metabolism are no longer activated. Conversely, a strain containing a constitutively active SurR variant displays a growth phenotype in the presence of S due to constitutive repression of S -responsive genes. During a metabolic shift initiated by addition of S to the growth medium, both strains demonstrate a de-regulation of genes involved in the SurR regulon, including hydrogenase and related S -responsive genes. These results demonstrate that SurR is a master regulator of electron flow within P. furiosus, likely affecting the pools of ferredoxin, NADPH and NADH, as well as influencing metabolic pathways and thiol/disulfide redox balance.
[Mh] Termos MeSH primário: Pyrococcus furiosus/metabolismo
Enxofre/metabolismo
[Mh] Termos MeSH secundário: Proteínas Arqueais/metabolismo
Elétrons
Regulação da Expressão Gênica em Archaea
Genes Reguladores
Hidrogênio/metabolismo
NADP/metabolismo
Oxirredução
Oxirredutases/metabolismo
Pyrococcus furiosus/genética
Ativação Transcricional
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Archaeal Proteins); 53-59-8 (NADP); 70FD1KFU70 (Sulfur); 7YNJ3PO35Z (Hydrogen); EC 1.- (Oxidoreductases)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171102
[Lr] Data última revisão:
171102
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170316
[St] Status:MEDLINE
[do] DOI:10.1111/mmi.13668


  9 / 614 MEDLINE  
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[PMID]:28115546
[Au] Autor:Hwang S; Cordova B; Abdo M; Pfeiffer F; Maupin-Furlow JA
[Ad] Endereço:Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA.
[Ti] Título:ThiN as a Versatile Domain of Transcriptional Repressors and Catalytic Enzymes of Thiamine Biosynthesis.
[So] Source:J Bacteriol;199(7), 2017 Apr 01.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Thiamine biosynthesis is commonly regulated by a riboswitch mechanism; however, the enzymatic steps and regulation of this pathway in archaea are poorly understood. , one of the representative archaea, uses a eukaryote-like Thi4 (thiamine thiazole synthase) for the production of the thiazole ring and condenses this ring with a pyrimidine moiety synthesized by an apparent bacterium-like ThiC (2-methyl-4-amino-5-hydroxymethylpyrimidine [HMP] phosphate synthase) branch. Here we found that archaeal Thi4 and ThiC were encoded by leaderless transcripts, ruling out a riboswitch mechanism. Instead, a novel ThiR transcription factor that harbored an N-terminal helix-turn-helix (HTH) DNA binding domain and C-terminal ThiN (TMP synthase) domain was identified. In the presence of thiamine, ThiR was found to repress the expression of and by a DNA operator sequence that was conserved across archaeal phyla. Despite having a ThiN domain, ThiR was found to be catalytically inactive in compensating for the loss of ThiE (TMP synthase) function. In contrast, bifunctional ThiDN, in which the ThiN domain is fused to an N-terminal ThiD (HMP/HMP phosphate [HMP-P] kinase) domain, was found to be interchangeable for ThiE function and, thus, active in thiamine biosynthesis. A conserved Met residue of an extended α-helix near the active-site His of the ThiN domain was found to be important for ThiDN catalytic activity, whereas the corresponding Met residue was absent and the α-helix was shorter in ThiR homologs. Thus, we provide new insight into residues that distinguish catalytic from noncatalytic ThiN domains and reveal that thiamine biosynthesis in archaea is regulated by a transcriptional repressor, ThiR, and not by a riboswitch. Thiamine pyrophosphate (TPP) is a cofactor needed for the enzymatic activity of many cellular processes, including central metabolism. In archaea, thiamine biosynthesis is an apparent chimera of eukaryote- and bacterium-type pathways that is not well defined at the level of enzymatic steps or regulatory mechanisms. Here we find that ThiN is a versatile domain of transcriptional repressors and catalytic enzymes of thiamine biosynthesis in archaea. Our study provides new insight into residues that distinguish catalytic from noncatalytic ThiN domains and reveals that archaeal thiamine biosynthesis is regulated by a ThiN domain transcriptional repressor, ThiR, and not by a riboswitch.
[Mh] Termos MeSH primário: Proteínas Arqueais/metabolismo
Regulação da Expressão Gênica em Archaea/fisiologia
Haloferax volcanii/metabolismo
Tiamina/biossíntese
Fatores de Transcrição/fisiologia
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Proteínas Arqueais/genética
DNA Arqueal/genética
Modelos Moleculares
Estrutura Molecular
Conformação de Ácido Nucleico
Ligação Proteica
Conformação Proteica
Purinas/química
Purinas/metabolismo
Tiamina/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Archaeal Proteins); 0 (DNA, Archaeal); 0 (Purines); 0 (Transcription Factors); X66NSO3N35 (Thiamine)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170914
[Lr] Data última revisão:
170914
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170125
[St] Status:MEDLINE


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[PMID]:28069824
[Au] Autor:Abdul Halim MF; Stoltzfus JD; Schulze S; Hippler M; Pohlschroder M
[Ad] Endereço:University of Pennsylvania, Department of Biology, Philadelphia, Pennsylvania, USA.
[Ti] Título:ArtA-Dependent Processing of a Tat Substrate Containing a Conserved Tripartite Structure That Is Not Localized at the C Terminus.
[So] Source:J Bacteriol;199(7), 2017 Apr 01.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Most prokaryote-secreted proteins are transported to the cell surface using either the general secretion (Sec) or twin-arginine translocation (Tat) pathway. A majority of secreted proteins are anchored to the cell surface, while the remainder are released into the extracellular environment. The anchored surface proteins play a variety of important roles in cellular processes, ranging from facilitating interactions between cells to maintaining cell stability. The extensively studied S-layer glycoprotein (SLG) of , previously thought to be anchored via C-terminal intercalation into the membrane, was recently shown to be lipidated and to have its C-terminal segment removed in processes dependent upon archaeosortase A (ArtA), a recently discovered enzyme. While SLG is a Sec substrate, analyses presented here reveal that, of eight additional ArtA substrates predicted, two substrates also contain predicted Tat signal peptides, including Hvo_0405, which has a highly conserved tripartite structure that lies closer to the center of the protein than to its C terminus, unlike other predicted ArtA substrates identified to date. We demonstrate that, even given its atypical location, this tripartite structure, which likely resulted from the fusion of genes encoding an ArtA substrate and a cytoplasmic protein, is processed in an ArtA-dependent manner. Using an Hvo_0405 mutant lacking the conserved "twin" arginines of the predicted Tat signal peptide, we show that Hvo_0405 is indeed a Tat substrate and that ArtA substrates include both Sec and Tat substrates. Finally, we confirmed the Tat-dependent localization and signal peptidase I (SPase I) cleavage site of Hvo_0405 using mass spectrometry. The specific mechanisms that facilitate protein anchoring to the archaeal cell surface remain poorly understood. Here, we have shown that the proteins bound to the cell surface of the model archaeon , through a recently discovered novel ArtA-dependent anchoring mechanism, are more structurally diverse than was previously known. Specifically, our results demonstrate that both Tat and Sec substrates, which contain the conserved tripartite structure of predicted ArtA substrates, can be processed in an ArtA-dependent manner and that the tripartite structure need not lie near the C terminus for this processing to occur. These data improve our understanding of archaeal cell biology and are invaluable for subcellular localization predictions of archaeal and bacterial proteins.
[Mh] Termos MeSH primário: Proteínas Arqueais/metabolismo
Regulação da Expressão Gênica em Archaea/fisiologia
Haloferax volcanii/metabolismo
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Proteínas Arqueais/genética
Sequência de Bases
DNA Arqueal/genética
Haloferax volcanii/genética
Mutagênese Sítio-Dirigida
Conformação Proteica
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Archaeal Proteins); 0 (DNA, Archaeal)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170914
[Lr] Data última revisão:
170914
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170111
[St] Status:MEDLINE



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