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[PMID]:28579332
[Au] Autor:Glyde R; Ye F; Darbari VC; Zhang N; Buck M; Zhang X
[Ad] Endereço:Section of Structural Biology, Department of Medicine, Imperial College London, London SW7 2AZ, UK.
[Ti] Título:Structures of RNA Polymerase Closed and Intermediate Complexes Reveal Mechanisms of DNA Opening and Transcription Initiation.
[So] Source:Mol Cell;67(1):106-116.e4, 2017 Jul 06.
[Is] ISSN:1097-4164
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Gene transcription is carried out by RNA polymerases (RNAPs). For transcription to occur, the closed promoter complex (RPc), where DNA is double stranded, must isomerize into an open promoter complex (RPo), where the DNA is melted out into a transcription bubble and the single-stranded template DNA is delivered to the RNAP active site. Using a bacterial RNAP containing the alternative σ factor and cryoelectron microscopy, we determined structures of RPc and the activator-bound intermediate complex en route to RPo at 3.8 and 5.8 Å. Our structures show how RNAP-σ interacts with promoter DNA to initiate the DNA distortions required for transcription bubble formation, and how the activator interacts with RPc, leading to significant conformational changes in RNAP and σ that promote RPo formation. We propose that DNA melting is an active process initiated in RPc and that the RNAP conformations of intermediates are significantly different from that of RPc and RPo.
[Mh] Termos MeSH primário: DNA de Cadeia Simples/metabolismo
Escherichia coli/enzimologia
Klebsiella pneumoniae/enzimologia
Desnaturação de Ácido Nucleico
RNA Polimerase Sigma 54/metabolismo
Iniciação da Transcrição Genética
[Mh] Termos MeSH secundário: Sítios de Ligação
Microscopia Crioeletrônica
DNA de Cadeia Simples/genética
DNA de Cadeia Simples/ultraestrutura
Escherichia coli/genética
Regulação Bacteriana da Expressão Gênica
Klebsiella pneumoniae/genética
Simulação de Acoplamento Molecular
Conformação de Ácido Nucleico
Regiões Promotoras Genéticas
Ligação Proteica
Conformação Proteica
RNA Polimerase Sigma 54/genética
RNA Polimerase Sigma 54/ultraestrutura
Relação Estrutura-Atividade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Single-Stranded); EC 2.7.7.6 (RNA Polymerase Sigma 54)
[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:170606
[St] Status:MEDLINE


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[PMID]:28373272
[Au] Autor:Bono AC; Hartman CE; Solaimanpour S; Tong H; Porwollik S; McClelland M; Frye JG; Mrázek J; Karls AC
[Ad] Endereço:Department of Microbiology, University of Georgia, Athens, Georgia, USA.
[Ti] Título:Novel DNA Binding and Regulatory Activities for σ (RpoN) in Salmonella enterica Serovar Typhimurium 14028s.
[So] Source:J Bacteriol;199(12), 2017 Jun 15.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The variable sigma (σ) subunit of the bacterial RNA polymerase (RNAP) holoenzyme, which is responsible for promoter specificity and open complex formation, plays a strategic role in the response to environmental changes. serovar Typhimurium utilizes the housekeeping σ and five alternative sigma factors, including σ The σ -RNAP differs from other σ-RNAP holoenzymes in that it forms a stable closed complex with the promoter and requires ATP hydrolysis by an activated cognate bacterial enhancer binding protein (bEBP) to transition to an open complex and initiate transcription. In Typhimurium, σ -dependent promoters normally respond to one of 13 different bEBPs, each of which is activated under a specific growth condition. Here, we utilized a constitutively active, promiscuous bEBP to perform a genome-wide identification of σ -RNAP DNA binding sites and the transcriptome of the σ regulon of Typhimurium. The position and context of many of the identified σ RNAP DNA binding sites suggest regulatory roles for σ -RNAP that connect the σ regulon to regulons of other σ factors to provide a dynamic response to rapidly changing environmental conditions. The alternative sigma factor σ (RpoN) is required for expression of genes involved in processes with significance in agriculture, bioenergy production, bioremediation, and host-microbe interactions. The characterization of the σ regulon of the versatile pathogen Typhimurium has expanded our understanding of the scope of the σ regulon and how it links to other σ regulons within the complex regulatory network for gene expression in bacteria.
[Mh] Termos MeSH primário: DNA Bacteriano/metabolismo
Regulação Bacteriana da Expressão Gênica
RNA Polimerase Sigma 54/metabolismo
Salmonella typhimurium/genética
Salmonella typhimurium/metabolismo
[Mh] Termos MeSH secundário: Sítios de Ligação
Perfilação da Expressão Gênica
Ligação Proteica
Regulon
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Bacterial); EC 2.7.7.6 (RNA Polymerase Sigma 54)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:171126
[Lr] Data última revisão:
171126
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170405
[St] Status:MEDLINE


  3 / 531 MEDLINE  
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[PMID]:28167521
[Au] Autor:Lundgren BR; Bailey FJ; Moley G; Nomura CT
[Ad] Endereço:Department of Chemistry, State University of New York, College of Environmental Science and Forestry, Syracuse, New York, USA.
[Ti] Título:DdaR (PA1196) Regulates Expression of Dimethylarginine Dimethylaminohydrolase for the Metabolism of Methylarginines in Pseudomonas aeruginosa PAO1.
[So] Source:J Bacteriol;199(8), 2017 Apr 15.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Dimethylarginine dimethylaminohydrolases (DDAHs) catalyze the hydrolysis of methylarginines to yield l-citrulline and methylamines as products. DDAHs and their central roles in methylarginine metabolism have been characterized for eukaryotic cells. While DDAHs are known to exist in some bacteria, including and , the physiological importance and genetic regulation of bacterial DDAHs remain poorly understood. To provide some insight into bacterial methylarginine metabolism, this study focused on identifying the key elements or factors regulating DDAH expression in PAO1. First, results revealed that can utilize , -dimethyl-l-arginine (ADMA) as a sole source of nitrogen but not carbon. Second, expression of the gene was observed to be induced in the presence of methylarginines, including -monomethyl-l-arginine (l-NMMA) and ADMA. Third, induction of the gene was shown to be achieved through a mechanism consisting of the putative enhancer-binding protein PA1196 and the alternative sigma factor RpoN. Both PA1196 and RpoN were essential for the expression of the gene in response to methylarginines. On the basis of the results of this study, PA1196 was given the name DdaR, for imethylarginine imethyl minohydrolase egulator. Interestingly, DdaR and its target gene are conserved only among strains, suggesting that this particular species has evolved to utilize methylarginines from its environment. Methylated arginine residues are common constituents of eukaryotic proteins. During proteolysis, methylarginines are released in their free forms and become accessible nutrients for bacteria to utilize as growth substrates. In order to have a clearer and better understanding of this process, we explored methylarginine utilization in the metabolically versatile bacterium PAO1. Our results show that the transcriptional regulator DdaR (PA1196) and the sigma factor RpoN positively regulate expression of dimethylarginine dimethylaminohydrolases (DDAHs) in response to exogenous methylarginines. DDAH is the central enzyme of methylarginine degradation, and its transcriptional regulation by DdaR-RpoN is expected to be conserved among strains.
[Mh] Termos MeSH primário: Amidoidrolases/metabolismo
Arginina/análogos & derivados
Regulação Bacteriana da Expressão Gênica/fisiologia
Regulação Enzimológica da Expressão Gênica/fisiologia
Pseudomonas aeruginosa/enzimologia
ômega-N-Metilarginina/metabolismo
[Mh] Termos MeSH secundário: Amidoidrolases/genética
Arginina/genética
Arginina/metabolismo
Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Pseudomonas aeruginosa/metabolismo
RNA Polimerase Sigma 54/genética
RNA Polimerase Sigma 54/metabolismo
ômega-N-Metilarginina/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 27JT06E6GR (omega-N-Methylarginine); 49787G1ULV (symmetric dimethylarginine); 63CV1GEK3Y (N,N-dimethylarginine); 94ZLA3W45F (Arginine); EC 2.7.7.6 (RNA Polymerase Sigma 54); EC 3.5.- (Amidohydrolases); EC 3.5.3.18 (dimethylargininase)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170928
[Lr] Data última revisão:
170928
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170208
[St] Status:MEDLINE


  4 / 531 MEDLINE  
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[PMID]:28031123
[Au] Autor:Liu S
[Ad] Endereço:Department of Clinical Laboratory, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China. *Corresponding author, E-mail: liushuang498@163.com.
[Ti] Título:[Preparation of polyclonal antibody against recombinant sigma protein from Helicobacter pylori].
[So] Source:Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi;33(1):100-103, 2017 Jan.
[Is] ISSN:1007-8738
[Cp] País de publicação:China
[La] Idioma:chi
[Ab] Resumo:Objective To express and purify recombinant sigma protein of Helicobacter pylori, and prepare polyclonal antibody against sigma protein. Methods Intact rpoN gene fragment was amplified from Helicobacter pylori (H. pylori) 26695 genome, and then cloned into prokaryotic expression vector pTriEx -4 with His coding sequence. The recombinant plasmid was transformed into E.coli JM109DE. The recombinant protein with 6-His tag was expressed by IPTG induction and purified by His-Bind affinity columns. The purified protein supplemented with adjuvant was used to immunize rabbits to obtain the polyclonal antibody. Results Recombinant sigma protein was successfully expressed in E.coli JM109DE. SDS-PAGE that was used to detect the purified protein showed a single band which was consistent with the expected size of the recombinant protein. The polyclonal antibody exhibited a good recognition and specificity against sigma protein. Conclusion The study successfully expressed and purified sigma protein, and obtained its polyclonal antibody.
[Mh] Termos MeSH primário: Anticorpos/imunologia
Helicobacter pylori/imunologia
RNA Polimerase Sigma 54/imunologia
Proteínas Recombinantes de Fusão/imunologia
[Mh] Termos MeSH secundário: Especificidade de Anticorpos/imunologia
Escherichia coli/genética
Expressão Gênica/genética
Vetores Genéticos/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Antibodies); 0 (Recombinant Fusion Proteins); EC 2.7.7.6 (RNA Polymerase Sigma 54)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170713
[Lr] Data última revisão:
170713
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161230
[St] Status:MEDLINE


  5 / 531 MEDLINE  
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[PMID]:27966049
[Au] Autor:Li LF; Fu LJ; Lin JQ; Pang X; Liu XM; Wang R; Wang ZB; Lin JQ; Chen LX
[Ad] Endereço:State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, 250100, People's Republic of China.
[Ti] Título:The σ -dependent two-component system regulating sulfur oxidization (Sox) system in Acidithiobacillus caldus and some chemolithotrophic bacteria.
[So] Source:Appl Microbiol Biotechnol;101(5):2079-2092, 2017 Mar.
[Is] ISSN:1432-0614
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:The sulfur oxidization (Sox) system is the central sulfur oxidization pathway of phototrophic and chemotrophic sulfur-oxidizing bacteria. Regulation and function of the Sox system in the chemotrophic Paracoccus pantotrophus has been elucidated; however, to date, no information is available on the regulation of this system in the chemolithotrophic Acidithiobacillus caldus, which is widely utilized in bioleaching. We described the novel tspSR-sox-like clusters in A. caldus and other chemolithotrophic sulfur-oxidizing bacteria containing Sox systems. The highly homologous σ -dependent two-component signaling system (TspS/R), upstream of the sox operons in these novel clusters, was identified by phylogenetic analyses. A typical σ -dependent promoter, P , was identified upstream of soxX-I in the sox-I cluster of A. caldus MTH-04. The transcriptional start site (G) and the -12/-24 regions (GC/GG) of P were determined by rapid amplification of cDNA ends (5'RACE), and the upstream activator sequences (UASs; TGTCCCAAATGGGACA) were confirmed by electrophoretic mobility shift assays (EMSAs) in vitro and by UAS-probe-plasmids assays in vivo. Sequence analysis of promoter regions in tspSR-sox-like clusters revealed that there were similar σ -dependent promoters upstream of the soxX genes. Based on our results, we proposed a TspSR-mediated signal transduction and transcriptional regulation pathway for the Sox system in A. caldus. The regulation of σ -dependent two-component systems (TCSs) for Sox pathways were explained for the first time in A. caldus, A. thiooxidans, T. tepidarius, and T. denitrificans, indicating the significance of modulating the sulfur oxidization in these chemolithotrophic sulfur oxidizers.
[Mh] Termos MeSH primário: Acidithiobacillus/genética
Regulação Bacteriana da Expressão Gênica
RNA Polimerase Sigma 54/genética
Sequências Reguladoras de Ácido Nucleico/genética
Enxofre/metabolismo
[Mh] Termos MeSH secundário: Acidithiobacillus/metabolismo
Sequência de Bases
Ensaio de Desvio de Mobilidade Eletroforética
Oxirredução
Regiões Promotoras Genéticas/genética
Análise de Sequência de DNA
Transdução de Sinais/genética
Ativação Transcricional/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
70FD1KFU70 (Sulfur); EC 2.7.7.6 (RNA Polymerase Sigma 54)
[Em] Mês de entrada:1702
[Cu] Atualização por classe:170227
[Lr] Data última revisão:
170227
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161215
[St] Status:MEDLINE
[do] DOI:10.1007/s00253-016-8026-2


  6 / 531 MEDLINE  
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[PMID]:27696536
[Au] Autor:Ouyang Z; Zhou J
[Ad] Endereço:Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
[Ti] Título:The putative Walker A and Walker B motifs of Rrp2 are required for the growth of Borrelia burgdorferi.
[So] Source:Mol Microbiol;103(1):86-98, 2017 01.
[Is] ISSN:1365-2958
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Rrp2 encodes a putative bacterial enhancer binding protein (bEBP) in Borrelia burgdorferi. Point mutation (G239C) of Rrp2 abolishes the transcriptional activation of σ -dependent rpoS. In contrast to canonical bEBPs that are dispensable for bacterial growth, Rrp2 is essential for borrelial growth in BSK medium. It has been believed that Rrp2's ATPase activity is not required for cell growth, but experimental evidence supporting this notion has been lacking. In particular, it has remained unclear whether the residue G239 is involved in Rrp2's presumptive ATPase activity. To address these information gaps, we examined the roles of Rrp2's potential strategic signatures including the G239 residue and the putative Walker A and Walker B motifs. Herein it was showed that Rrp2 has ATP binding and hydrolysis activities engendered by the Walker A and B motifs respectively. However, these activities were not significantly impaired by a G239C mutation. Further mutagenesis analyses indicated that Rrp2's Walker A and B motifs are required for borrelial growth; mutations of key residues in these two motifs were lethal to B. burgdorferi. The combined data suggest that the Walker A and Walker B motifs of Rrp2 are involved in the control of another unknown RpoS-independent gene product(s) associated with borrelial replication.
[Mh] Termos MeSH primário: Borrelia burgdorferi/metabolismo
Proteínas de Ligação a DNA/metabolismo
Fatores de Transcrição/metabolismo
[Mh] Termos MeSH secundário: Motivos de Aminoácidos
Antígenos de Bactérias/metabolismo
Proteínas da Membrana Bacteriana Externa/metabolismo
Proteínas de Bactérias/metabolismo
Borrelia burgdorferi/crescimento & desenvolvimento
Replicação do DNA/fisiologia
Regulação Bacteriana da Expressão Gênica/genética
Mutagênese
Mutação
RNA Polimerase Sigma 54/genética
Fator sigma/metabolismo
Ativação Transcricional/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Nm] Nome de substância:
0 (Antigens, Bacterial); 0 (Bacterial Outer Membrane Proteins); 0 (Bacterial Proteins); 0 (DNA-Binding Proteins); 0 (Sigma Factor); 0 (Transcription Factors); 0 (sigma factor KatF protein, Bacteria); EC 2.7.7.6 (RNA Polymerase Sigma 54)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:171031
[Lr] Data última revisão:
171031
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161004
[St] Status:MEDLINE
[do] DOI:10.1111/mmi.13545


  7 / 531 MEDLINE  
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[PMID]:27789741
[Au] Autor:Zhang N; Darbari VC; Glyde R; Zhang X; Buck M
[Ad] Endereço:Division of Cell and Molecular Biology, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, London SW7 2AZ, U.K. Neuroscience Research Program, Houston Methodist Research Institute, 6670 Bertner Avenue, Houston, TX 77030, U.S.A.
[Ti] Título:The bacterial enhancer-dependent RNA polymerase.
[So] Source:Biochem J;473(21):3741-3753, 2016 Nov 01.
[Is] ISSN:1470-8728
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Transcription initiation is highly regulated in bacterial cells, allowing adaptive gene regulation in response to environment cues. One class of promoter specificity factor called sigma54 enables such adaptive gene expression through its ability to lock the RNA polymerase down into a state unable to melt out promoter DNA for transcription initiation. Promoter DNA opening then occurs through the action of specialized transcription control proteins called bacterial enhancer-binding proteins (bEBPs) that remodel the sigma54 factor within the closed promoter complexes. The remodelling of sigma54 occurs through an ATP-binding and hydrolysis reaction carried out by the bEBPs. The regulation of bEBP self-assembly into typically homomeric hexamers allows regulated gene expression since the self-assembly is required for bEBP ATPase activity and its direct engagement with the sigma54 factor during the remodelling reaction. Crystallographic studies have now established that in the closed promoter complex, the sigma54 factor occupies the bacterial RNA polymerase in ways that will physically impede promoter DNA opening and the loading of melted out promoter DNA into the DNA-binding clefts of the RNA polymerase. Large-scale structural re-organizations of sigma54 require contact of the bEBP with an amino-terminal glutamine and leucine-rich sequence of sigma54, and lead to domain movements within the core RNA polymerase necessary for making open promoter complexes and synthesizing the nascent RNA transcript.
[Mh] Termos MeSH primário: Proteínas de Bactérias/metabolismo
RNA Polimerases Dirigidas por DNA/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
RNA Polimerases Dirigidas por DNA/genética
Elementos Facilitadores Genéticos/genética
Regulação Bacteriana da Expressão Gênica/genética
Regulação Bacteriana da Expressão Gênica/fisiologia
RNA Polimerase Sigma 54/genética
RNA Polimerase Sigma 54/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Bacterial Proteins); EC 2.7.7.6 (DNA-Directed RNA Polymerases); EC 2.7.7.6 (RNA Polymerase Sigma 54)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161030
[St] Status:MEDLINE


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[PMID]:27732872
[Au] Autor:Siegel AR; Wemmer DE
[Ad] Endereço:Biophysics Graduate Group, University of California, Berkeley, CA 94720, USA.
[Ti] Título:Role of the σ Activator Interacting Domain in Bacterial Transcription Initiation.
[So] Source:J Mol Biol;428(23):4669-4685, 2016 Nov 20.
[Is] ISSN:1089-8638
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Bacterial sigma factors are subunits of RNA polymerase that direct the holoenzyme to specific sets of promoters in the genome and are a central element of regulating transcription. Most polymerase holoenzymes open the promoter and initiate transcription rapidly after binding. However, polymerase containing the members of the σ family must be acted on by a transcriptional activator before DNA opening and initiation occur. A key domain in these transcriptional activators forms a hexameric AAA+ ATPase that acts through conformational changes brought on by ATP hydrolysis. Contacts between the transcriptional activator and σ are primarily made through an N-terminal σ activator interacting domain (AID). To better understand this mechanism of bacterial transcription initiation, we characterized the σ AID by NMR spectroscopy and other biophysical methods and show that it is an intrinsically disordered domain in σ alone. We identified a minimal construct of the Aquifex aeolicus σ AID that consists of two predicted helices and retains native-like binding affinity for the transcriptional activator NtrC1. Using the NtrC1 ATPase domain, bound with the non-hydrolyzable ATP analog ADP-beryllium fluoride, we studied the NtrC1-σ AID complex using NMR spectroscopy. We show that the σ AID becomes structured after associating with the core loops of the transcriptional activators in their ATP state and that the primary site of the interaction is the first predicted helix. Understanding this complex, formed as the first step toward initiation, will help unravel the mechanism of σ bacterial transcription initiation.
[Mh] Termos MeSH primário: Bactérias/química
Bactérias/enzimologia
RNA Polimerase Sigma 54/química
RNA Polimerase Sigma 54/metabolismo
Transcrição Genética
[Mh] Termos MeSH secundário: Trifosfato de Adenosina/metabolismo
Bactérias/genética
Espectroscopia de Ressonância Magnética
Modelos Moleculares
Ligação Proteica
Conformação Proteica
Domínios Proteicos
RNA Polimerase Sigma 54/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
8L70Q75FXE (Adenosine Triphosphate); EC 2.7.7.6 (RNA Polymerase Sigma 54)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:171120
[Lr] Data última revisão:
171120
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161013
[St] Status:MEDLINE


  9 / 531 MEDLINE  
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[PMID]:27193545
[Au] Autor:Zhang N; Jovanovic G; McDonald C; Ces O; Zhang X; Buck M
[Ad] Endereço:Division of Cell and Molecular Biology, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, London, SW7 2AZ, UK.
[Ti] Título:Transcription Regulation and Membrane Stress Management in Enterobacterial Pathogens.
[So] Source:Adv Exp Med Biol;915:207-30, 2016.
[Is] ISSN:0065-2598
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Transcription regulation in a temporal and conditional manner underpins the lifecycle of enterobacterial pathogens. Upon exposure to a wide array of environmental cues, these pathogens modulate their gene expression via the RNA polymerase and associated sigma factors. Different sigma factors, either involved in general 'house-keeping' or specific responses, guide the RNA polymerase to their cognate promoter DNAs. The major alternative sigma54 factor when activated helps pathogens manage stresses and proliferate in their ecological niches. In this chapter, we review the function and regulation of the sigma54-dependent Phage shock protein (Psp) system-a major stress response when Gram-negative pathogens encounter damages to their inner membranes. We discuss the recent development on mechanisms of gene regulation, signal transduction and stress mitigation in light of different biophysical and biochemical approaches.
[Mh] Termos MeSH primário: Membrana Celular/fisiologia
Enterobacteriaceae/fisiologia
Regulação Bacteriana da Expressão Gênica
RNA Polimerase Sigma 54/metabolismo
Estresse Fisiológico
Transcrição Genética
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Membrana Celular/metabolismo
Enterobacteriaceae/genética
Enterobacteriaceae/metabolismo
Proteínas de Choque Térmico/genética
Proteínas de Choque Térmico/metabolismo
Interações Hospedeiro-Patógeno
Modelos Moleculares
Conformação Proteica
RNA Polimerase Sigma 54/química
RNA Polimerase Sigma 54/genética
Transdução de Sinais
Relação Estrutura-Atividade
Transativadores/genética
Transativadores/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; REVIEW
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Heat-Shock Proteins); 0 (Trans-Activators); 0 (phage shock protein, Bacteria); EC 2.7.7.6 (RNA Polymerase Sigma 54)
[Em] Mês de entrada:1609
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160520
[St] Status:MEDLINE
[do] DOI:10.1007/978-3-319-32189-9_13


  10 / 531 MEDLINE  
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[PMID]:26961967
[Au] Autor:de Las Heras A; Martínez-García E; Domingo-Sananes MR; Fraile S; de Lorenzo V
[Ad] Endereço:Systems Biology Program, Centro Nacional de Biotecnología-CSIC, Campus de Cantoblanco, Madrid 28049, Spain. vdlorenzo@cnb.csic.es.
[Ti] Título:Rationally rewiring the connectivity of the XylR/Pu regulatory node of the m-xylene degradation pathway in Pseudomonas putida.
[So] Source:Integr Biol (Camb);8(4):571-6, 2016 Apr 18.
[Is] ISSN:1757-9708
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The XylR/Pu regulatory node of the m-xylene biodegradation pathway of Pseudomonas putida mt-2 is one of the most intricate cases of processing internal and external cues into a single controlling element. Despite this complexity, the performance of the regulatory system is determined in vivo only by the occupation of Pu by m-xylene-activated XylR and σ(54)-RNAP. The stoichiometry between these three elements defines natural system boundaries that outline a specific functional space. This space can be expanded artificially following different strategies that involve either the increase of XylR or σ(54) or both elements at the same time (each using a different inducer). In this work we have designed a new regulatory architecture that drives the system to reach a maximum performance in response to one single input. To this end, we first explored using a simple mathematical model whether the output of the XylR/Pu node could be amended by simultaneously increasing σ(54) and XylR in response to only natural inducers. The exacerbation of Pu activity in vivo was tested in strains bearing synthetic transposons encoding xylR and rpoN (the σ(54) coding gene) controlled also by Pu, thereby generating a P. putida strain with the XylR/Pu output controlled by two intertwined feed forward loops (FFLs). The lack of a negative feedback loop in the expression node enables Pu activity to reach its physiological maximum in response to a single input. Only competition for cell resources might ultimately check the upper activity limit of such a rewired m-xylene sensing device.
[Mh] Termos MeSH primário: Regulação Bacteriana da Expressão Gênica
Pseudomonas putida/genética
Xilenos/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Proteínas de Ligação a DNA/genética
Escherichia coli/genética
Proteínas de Escherichia coli/genética
Engenharia Genética/métodos
Modelos Genéticos
Plasmídeos/metabolismo
Pseudomonas putida/metabolismo
RNA Polimerase Sigma 54/genética
Fator sigma/metabolismo
Biologia Sintética/métodos
Fatores de Transcrição/genética
Fatores de Transcrição/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (DNA-Binding Proteins); 0 (Escherichia coli Proteins); 0 (Sigma Factor); 0 (Transcription Factors); 0 (XylR protein, Pseudomonas); 0 (Xylenes); 0 (rpoN protein, E coli); EC 2.7.7.6 (RNA Polymerase Sigma 54); O9XS864HTE (3-xylene)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:170307
[Lr] Data última revisão:
170307
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160311
[St] Status:MEDLINE
[do] DOI:10.1039/c5ib00310e



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