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[PMID]:28461451
[Au] Autor:Li L; Jiang W; Lu Y
[Ad] Endereço:Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.
[Ti] Título:A Novel Two-Component System, GluR-GluK, Involved in Glutamate Sensing and Uptake in Streptomyces coelicolor.
[So] Source:J Bacteriol;199(18), 2017 09 15.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Two-component systems (TCSs), the predominant signal transduction pathways employed by bacteria, play important roles in physiological metabolism in Here, a novel TCS, GluR-GluK (encoded by ), which is located divergently from the operon encoding a glutamate uptake system, was identified as being involved in glutamate sensing and uptake as well as antibiotic biosynthesis in Under the condition of minimal medium (MM) supplemented with different concentrations of glutamate, deletion of the operon ( ) resulted in enhanced actinorhodin (ACT) but reduced undecylprodigiosin (RED) and yellow type I polyketide (yCPK) production, suggesting that GluR-GluK plays a differential role in antibiotic biosynthesis. Furthermore, we found that the response regulator GluR directly promotes the expression of under the culture condition of MM with a high concentration of glutamate (75 mM). Using the biolayer interferometry assay, we demonstrated that glutamate acts as the direct signal of the histidine kinase GluK. It was therefore suggested that upon sensing high concentrations of glutamate, GluR-GluK would be activated and thereby facilitate glutamate uptake by increasing expression. Finally, we demonstrated that the role of GluR-GluK in antibiotic biosynthesis is independent of its function in glutamate uptake. Considering the wide distribution of the glutamate-sensing (GluR-GluK) and uptake (GluABCD) module in actinobacteria, it could be concluded that the GluR-GluK signal transduction pathway involved in secondary metabolism and glutamate uptake should be highly conserved in this bacterial phylum. In this study, a novel two-component system (TCS), GluR-GluK, was identified to be involved in glutamate sensing and uptake as well as antibiotic biosynthesis in A possible GluR-GluK working model was proposed. Upon sensing high glutamate concentrations (such as 75 mM), activated GluR-GluK could regulate both glutamate uptake and antibiotic biosynthesis. However, under a culture condition of MM supplemented with low concentrations of glutamate (such as 10 mM), although GluR-GluK is activated, its activity is sufficient only for the regulation of antibiotic biosynthesis. To the best of our knowledge, this is the first report describing a TCS signal transduction pathway for glutamate sensing and uptake in actinobacteria.
[Mh] Termos MeSH primário: Ácido Glutâmico/metabolismo
Histidina Quinase/metabolismo
Transdução de Sinais
Streptomyces coelicolor/metabolismo
Fatores de Transcrição/metabolismo
[Mh] Termos MeSH secundário: Transporte Biológico
Meios de Cultura/química
Deleção de Genes
Regulação da Expressão Gênica
Histidina Quinase/genética
Proteínas de Membrana Transportadoras/genética
Proteínas de Membrana Transportadoras/metabolismo
Óperon
Streptomyces coelicolor/genética
Fatores de Transcrição/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Culture Media); 0 (Membrane Transport Proteins); 0 (Transcription Factors); 3KX376GY7L (Glutamic Acid); EC 2.7.13.1 (Histidine Kinase)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:180306
[Lr] Data última revisão:
180306
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170503
[St] Status:MEDLINE


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[PMID]:29288053
[Au] Autor:Neira JL; Hornos F; Cozza C; Cámara-Artigas A; Abián O; Velázquez-Campoy A
[Ad] Endereço:Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche, Alicante, Spain; Instituto de Biocomputación y Física de Sistemas Complejos, Joint Units IQFR-CSIC-BIFI, and GBsC-CSIC-BIFI, Universidad de Zaragoza, Spain. Electronic address: jlneira@umh.es.
[Ti] Título:The histidine phosphocarrier protein, HPr, binds to the highly thermostable regulator of sigma D protein, Rsd, and its isolated helical fragments.
[So] Source:Arch Biochem Biophys;639:26-37, 2018 02 01.
[Is] ISSN:1096-0384
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The phosphotransferase system (PTS) controls the preferential use of sugars in bacteria and it is also involved in other processes, such as chemotaxis. It is formed by a protein cascade in which the first two proteins are general (namely, EI and HPr) and the others are sugar-specific permeases. The Rsd protein binds specifically to the RNA polymerase (RNAP) σ factor. We first characterized the conformational stability of Escherichia coli Rsd. And second, we delineated the binding regions of Streptomyces coelicolor, HPr , and E. coli Rsd, by using fragments derived from each protein. To that end, we used several biophysical probes, namely, fluorescence, CD, NMR, ITC and BLI. Rsd had a free energy of unfolding of 15 kcal mol at 25 °C, and a thermal denaturation midpoint of 103 °C at pH 6.5. The affinity between Rsd and HPr was 2 µM. Interestingly enough, the isolated helical-peptides, comprising the third (RsdH3) and fourth (RsdH4) Rsd helices, also interacted with HPr in a specific manner, and with affinities similar to that of the whole Rsd. Moreover, the isolated peptide of HPr , HPr , comprising the active site, His15, also was bound to intact Rsd with similar affinity. Therefore, binding between Rsd and HPr was modulated by the two helices H3 and H4 of Rsd, and the regions around the active site of HPr . This implies that specific fragments of Rsd and HPr can be used to interfere with other protein-protein interactions (PPIs) of each other protein.
[Mh] Termos MeSH primário: Proteínas de Bactérias/química
Proteínas de Escherichia coli/química
Escherichia coli/química
Peptídeos/química
Sistema Fosfotransferase de Açúcar do Fosfoenolpiruvato/química
Proteínas Repressoras/química
Streptomyces coelicolor/química
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Domínio Catalítico
Escherichia coli/genética
Escherichia coli/metabolismo
Proteínas de Escherichia coli/genética
Proteínas de Escherichia coli/metabolismo
Peptídeos/genética
Peptídeos/metabolismo
Sistema Fosfotransferase de Açúcar do Fosfoenolpiruvato/genética
Sistema Fosfotransferase de Açúcar do Fosfoenolpiruvato/metabolismo
Estrutura Secundária de Proteína
Proteínas Repressoras/genética
Proteínas Repressoras/metabolismo
Streptomyces coelicolor/genética
Streptomyces coelicolor/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Escherichia coli Proteins); 0 (Peptides); 0 (Repressor Proteins); 0 (Rsd protein, E coli); EC 2.7.1.- (Phosphoenolpyruvate Sugar Phosphotransferase System); EC 2.7.1.- (phosphocarrier protein HPr)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180214
[Lr] Data última revisão:
180214
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171231
[St] Status:MEDLINE


  3 / 1080 MEDLINE  
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[PMID]:28463421
[Au] Autor:Wu C; Ichinose K; Choi YH; van Wezel GP
[Ad] Endereço:Molecular Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands.
[Ti] Título:Aromatic Polyketide GTRI-02 is a Previously Unidentified Product of the act Gene Cluster in Streptomyces coelicolor A3(2).
[So] Source:Chembiochem;18(14):1428-1434, 2017 07 18.
[Is] ISSN:1439-7633
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:The biosynthesis of aromatic polyketides derived from type II polyketide synthases (PKSs) is complex, and it is not uncommon that highly similar gene clusters give rise to diverse structural architectures. The act biosynthetic gene cluster (BGC) of the model actinomycete Streptomyces coelicolor A3(2) is an archetypal type II PKS. Here we show that the act BGC also specifies the aromatic polyketide GTRI-02 (1) and propose a mechanism for the biogenesis of its 3,4-dihydronaphthalen-1(2H)-one backbone. Polyketide 1 was also produced by Streptomyces sp. MBT76 after activation of the act-like qin gene cluster by overexpression of the pathway-specific activator. Mining of this strain also identified dehydroxy-GTRI-02 (2), which most likely originated from dehydration of 1 during the isolation process. This work shows that even extensively studied model gene clusters such as act of S. coelicolor can still produce new chemistry, offering new perspectives for drug discovery.
[Mh] Termos MeSH primário: Família Multigênica
Naftóis/metabolismo
Streptomyces coelicolor/genética
Streptomyces coelicolor/metabolismo
Tetra-Hidronaftalenos/metabolismo
[Mh] Termos MeSH secundário: Naftóis/química
Tetra-Hidronaftalenos/química
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (GTRI 02); 0 (Naphthols); 0 (Tetrahydronaphthalenes)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:180122
[Lr] Data última revisão:
180122
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170503
[St] Status:MEDLINE
[do] DOI:10.1002/cbic.201700107


  4 / 1080 MEDLINE  
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[PMID]:28455615
[Au] Autor:Meng S; Wu H; Wang L; Zhang B; Bai L
[Ad] Endereço:State Key Laboratory of Microbial Metabolism and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
[Ti] Título:Enhancement of antibiotic productions by engineered nitrate utilization in actinomycetes.
[So] Source:Appl Microbiol Biotechnol;101(13):5341-5352, 2017 Jul.
[Is] ISSN:1432-0614
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Nitrate is necessary for primary and secondary metabolism of actinomycetes and stimulates the production of a few antibiotics, such as lincomycin and rifamycin. However, the mechanism of this nitrate-stimulating effect was not fully understood. Two putative ABC-type nitrate transporters were identified in Streptomyces lincolnensis NRRL2936 and verified to be involved in lincomycin biosynthesis. With nitrate supplementation, the transcription of nitrogen assimilation genes, nitrate-specific ABC1 transporter genes, and lincomycin exporter gene lmrA was found to be enhanced and positively regulated by the global regulator GlnR, whose expression was also improved. Moreover, heterologous expression of ABC2 transporter genes in Streptomyces coelicolor M145 resulted in an increased actinorhodin production. Further incorporation of a nitrite-specific transporter gene nirC, as in nirC-ABC2 cassette, led to an even higher actinorhodin production. Similarly, the titers of salinomycin, ansamitocin, lincomycin, and geldanamycin were increased with the integration of this cassette to Streptomyces albus BK3-25, Actinosynnema pretiosum ATCC31280, S. lincolnensis LC-G, and Streptomyces hygroscopicus XM201, respectively. Our work expanded the nitrate-stimulating effect to many antibiotic producers by utilizing the nirC-ABC2 cassette for enhanced nitrate utilization, which could become a general tool for titer increase of antibiotics in actinomycetes.
[Mh] Termos MeSH primário: Actinobacteria/genética
Antibacterianos/biossíntese
Lincomicina/biossíntese
Nitratos/metabolismo
Streptomyces/genética
[Mh] Termos MeSH secundário: Actinobacteria/metabolismo
Proteínas de Transporte de Ânions/genética
Antraquinonas/metabolismo
Antibacterianos/metabolismo
Proteínas de Bactérias/genética
Regulação Bacteriana da Expressão Gênica
Nitrogênio/metabolismo
Piranos/metabolismo
Streptomyces/metabolismo
Streptomyces coelicolor/genética
Transativadores/genética
Transativadores/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anion Transport Proteins); 0 (Anthraquinones); 0 (Anti-Bacterial Agents); 0 (Bacterial Proteins); 0 (GlnR protein, Streptomyces coelicolor); 0 (NirC protein, Bacteria); 0 (Nitrates); 0 (Pyrans); 0 (Trans-Activators); 62UXS86T64 (salinomycin); BOD072YW0F (Lincomycin); G4HH387T6Z (actinorhodin); N762921K75 (Nitrogen)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180104
[Lr] Data última revisão:
180104
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170430
[St] Status:MEDLINE
[do] DOI:10.1007/s00253-017-8292-7


  5 / 1080 MEDLINE  
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[PMID]:28967743
[Au] Autor:Blank PN; Barrow GH; Chou WKW; Duan L; Cane DE; Christianson DW
[Ad] Endereço:Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104-6323, United States.
[Ti] Título:Substitution of Aromatic Residues with Polar Residues in the Active Site Pocket of epi-Isozizaene Synthase Leads to the Generation of New Cyclic Sesquiterpenes.
[So] Source:Biochemistry;56(43):5798-5811, 2017 Oct 31.
[Is] ISSN:1520-4995
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The sesquiterpene cyclase epi-isozizaene synthase (EIZS) catalyzes the cyclization of farnesyl diphosphate to form the tricyclic hydrocarbon precursor of the antibiotic albaflavenone. The hydrophobic active site pocket of EIZS serves as a template as it binds and chaperones the flexible substrate and carbocation intermediates through the conformations required for a multistep reaction sequence. We previously demonstrated that the substitution of hydrophobic residues with other hydrophobic residues remolds the template and expands product chemodiversity [Li, R., Chou, W. K. W., Himmelberger, J. A., Litwin, K. M., Harris, G. G., Cane, D. E., and Christianson, D. W. (2014) Biochemistry 53, 1155-1168]. Here, we show that the substitution of hydrophobic residues-specifically, Y69, F95, F96, and W203-with polar side chains also yields functional enzyme catalysts that expand product chemodiversity. Fourteen new EIZS mutants are reported that generate product arrays in which eight new sesquiterpene products have been identified. Of note, some mutants generate acyclic and cyclic hydroxylated products, suggesting that the introduction of polarity in the hydrophobic pocket facilitates the binding of water capable of quenching carbocation intermediates. Furthermore, the substitution of polar residues for F96 yields high-fidelity sesquisabinene synthases. Crystal structures of selected mutants reveal that residues defining the three-dimensional contour of the hydrophobic pocket can be substituted without triggering significant structural changes elsewhere in the active site. Thus, more radical nonpolar-polar amino acid substitutions should be considered when terpenoid cyclase active sites are remolded by mutagenesis with the goal of exploring and expanding product chemodiversity.
[Mh] Termos MeSH primário: Substituição de Aminoácidos
Proteínas de Bactérias/química
Carbono-Carbono Liases/química
Modelos Moleculares
Streptomyces coelicolor/enzimologia
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Carbono-Carbono Liases/genética
Carbono-Carbono Liases/metabolismo
Domínio Catalítico
Cristalografia por Raios X
Interações Hidrofóbicas e Hidrofílicas
Mutação de Sentido Incorreto
Sesquiterpenos/química
Sesquiterpenos/metabolismo
Streptomyces coelicolor/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Sesquiterpenes); EC 4.1.- (Carbon-Carbon Lyases); EC 4.2.3.6 (trichodiene synthetase)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171103
[Lr] Data última revisão:
171103
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171003
[St] Status:MEDLINE
[do] DOI:10.1021/acs.biochem.7b00895


  6 / 1080 MEDLINE  
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[PMID]:28692281
[Au] Autor:Buchko GW; Echols N; Flynn EM; Ng HL; Stephenson S; Kim HB; Myler PJ; Terwilliger TC; Alber T; Kim CY
[Ad] Endereço:Seattle Structural Genomics Center for Infectious Diseases.
[Ti] Título:Structural and Biophysical Characterization of the Mycobacterium tuberculosis Protein Rv0577, a Protein Associated with Neutral Red Staining of Virulent Tuberculosis Strains and Homologue of the Streptomyces coelicolor Protein KbpA.
[So] Source:Biochemistry;56(30):4015-4027, 2017 Aug 01.
[Is] ISSN:1520-4995
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Mycobacterium tuberculosis protein Rv0577 is a prominent antigen in tuberculosis patients, the component responsible for neutral red staining of virulent strains of M. tuberculosis, a putative component in a methylglyoxal detoxification pathway, and an agonist of toll-like receptor 2. It also has an amino acid sequence that is 36% identical to that of Streptomyces coelicolor AfsK-binding protein A (KbpA), a component in the complex secondary metabolite pathways in the Streptomyces genus. To gain insight into the biological function of Rv0577 and the family of KpbA kinase regulators, the crystal structure for Rv0577 was determined to a resolution of 1.75 Å, binding properties with neutral red and deoxyadenosine were surveyed, backbone dynamics were measured, and thermal stability was assayed by circular dichroism spectroscopy. The protein is composed of four approximate repeats with a ßαßßß topology arranged radially in consecutive pairs to form two continuous eight-strand ß-sheets capped on both ends with an α-helix. The two ß-sheets intersect in the center at roughly a right angle and form two asymmetric deep "saddles" that may serve to bind ligands. Nuclear magnetic resonance chemical shift perturbation experiments show that neutral red and deoxyadenosine bind to Rv0577. Binding to deoxyadenosine is weaker with an estimated dissociation constants of 4.1 ± 0.3 mM for saddle 1. Heteronuclear steady-state { H}- N nuclear Overhauser effect, T , and T values were generally uniform throughout the sequence with only a few modest pockets of differences. Circular dichroism spectroscopy characterization of the thermal stability of Rv0577 indicated irreversible unfolding upon heating with an estimated melting temperature of 56 °C.
[Mh] Termos MeSH primário: Proteínas de Bactérias/metabolismo
Desoxiadenosinas/metabolismo
Modelos Moleculares
Mycobacterium tuberculosis/metabolismo
Vermelho Neutro/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Bactérias/química
Proteínas de Bactérias/genética
Sítios de Ligação
Proteínas de Transporte/química
Proteínas de Transporte/genética
Proteínas de Transporte/metabolismo
Dicroísmo Circular
Cristalografia por Raios X
Desoxiadenosinas/química
Temperatura Alta/efeitos adversos
Cinética
Ligantes
Conformação Molecular
Vermelho Neutro/química
Isótopos de Nitrogênio
Ressonância Magnética Nuclear Biomolecular
Conformação Proteica
Conformação Proteica em alfa-Hélice
Conformação Proteica em Folha beta
Estabilidade Proteica
Proteínas Recombinantes de Fusão/química
Proteínas Recombinantes de Fusão/metabolismo
Streptomyces coelicolor/metabolismo
Homologia Estrutural de Proteína
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Carrier Proteins); 0 (Cfp32 protein, Mycobacterium tuberculosis); 0 (Deoxyadenosines); 0 (KbpA protein, Steptomyces coelicolor); 0 (Ligands); 0 (Nitrogen Isotopes); 0 (Recombinant Fusion Proteins); 261QK3SSBH (Neutral Red); P582C98ULC (2'-deoxyadenosine)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170811
[Lr] Data última revisão:
170811
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170711
[St] Status:MEDLINE
[do] DOI:10.1021/acs.biochem.7b00511


  7 / 1080 MEDLINE  
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[PMID]:28393452
[Au] Autor:Tang X; Li J; Moore BS
[Ad] Endereço:Center of Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0204, USA.
[Ti] Título:Minimization of the Thiolactomycin Biosynthetic Pathway Reveals that the Cytochrome P450 Enzyme TlmF Is Required for Five-Membered Thiolactone Ring Formation.
[So] Source:Chembiochem;18(12):1072-1076, 2017 Jun 19.
[Is] ISSN:1439-7633
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Thiolactomycin (TLM) belongs to a class of rare and unique thiotetronate antibiotics that inhibit bacterial fatty acid synthesis. Although this group of natural product antibiotics was first discovered over 30 years ago, the study of TLM biosynthesis remains in its infancy. We recently discovered the biosynthetic gene cluster (BGC) for TLM from the marine bacterium Salinispora pacifica CNS-863. Here, we report the investigation of TLM biosynthetic logic through mutagenesis and comparative metabolic analyses. Our results revealed that only four genes (tlmF, tlmG, tlmH, and tlmI) are required for the construction of the characteristic γ-thiolactone skeleton of this class of antibiotics. We further showed that the cytochrome P450 TlmF does not directly participate in sulfur insertion and C-S bond formation chemistry but rather in the construction of the five-membered thiolactone ring as, upon its deletion, we observed the alternative production of the six-membered δ-thiolactomycin. Our findings pave the way for future biochemical investigation of the biosynthesis of this structurally unique group of thiotetronic acid natural products.
[Mh] Termos MeSH primário: Antibacterianos/biossíntese
Proteínas de Bactérias/genética
Sistema Enzimático do Citocromo P-450/genética
Regulação Bacteriana da Expressão Gênica
Micromonosporaceae/genética
[Mh] Termos MeSH secundário: Antibacterianos/química
Organismos Aquáticos
Proteínas de Bactérias/metabolismo
Vias Biossintéticas/genética
Clonagem Molecular
Ciclização
Sistema Enzimático do Citocromo P-450/metabolismo
Escherichia coli/genética
Escherichia coli/metabolismo
Engenharia Genética
Micromonosporaceae/enzimologia
Família Multigênica
Mutagênese
Plasmídeos/química
Plasmídeos/metabolismo
Estereoisomerismo
Streptomyces coelicolor/genética
Streptomyces coelicolor/metabolismo
Tiofenos/química
Tiofenos/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Bacterial Agents); 0 (Bacterial Proteins); 0 (Thiophenes); 82079-32-1 (thiolactomycin); 9035-51-2 (Cytochrome P-450 Enzyme System)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170830
[Lr] Data última revisão:
170830
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170411
[St] Status:MEDLINE
[do] DOI:10.1002/cbic.201700090


  8 / 1080 MEDLINE  
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[PMID]:28369604
[Au] Autor:Yang CC; Tseng SM; Pan HY; Huang CH; Chen CW
[Ad] Endereço:Department of Chemistry, Chung-Yuan Christian University, Chung-li, Taiwan.
[Ti] Título:Telomere associated primase Tap repairs truncated telomeres of Streptomyces.
[So] Source:Nucleic Acids Res;45(10):5838-5849, 2017 Jun 02.
[Is] ISSN:1362-4962
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Replication of the linear chromosomes of soil bacteria Streptomyces proceeds from an internal origin towards the telomeres, followed by patching of the resulting terminal single-strand overhangs by DNA synthesis using terminal proteins as the primer, which remains covalently bound to the 5΄ ends of the DNA. In most Streptomyces chromosomes, the end patching requires the single-strand overhangs, terminal protein Tpg, and terminal associated protein Tap. The telomere overhangs contain several palindromic sequences capable of forming stable hairpins. Previous in vitro deoxynucleotidylation studies indicated that Tap adds the Palindrome I sequence to Tpg, which is extended by a polymerase to fill the gap. In this study, the stringency of Palindrome I sequence was examined by an in vitro deoxynucleotidylation system and in vivo replication. Several nt in Palindrome I were identified to be critical for priming. While the first 3 G on the template were required for deoxynucleotidylation in vitro, deletions of them could be suppressed by the presence of dGTP. In vivo, deletions of these G were also tolerated, and the telomere sequence was restored in the linear plasmid DNA. Our results indicated that the truncated telomeres were repaired by extension synthesis by Tap on the foldback Palindrome I sequence.
[Mh] Termos MeSH primário: Proteínas de Bactérias/genética
DNA Primase/genética
Reparo do DNA
Replicação do DNA
Streptomyces coelicolor/genética
Streptomyces lividans/genética
Telômero/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Bactérias/metabolismo
Pareamento de Bases
Sequência de Bases
Cromossomos Bacterianos/química
DNA Primase/metabolismo
Conformação de Ácido Nucleico
Plasmídeos/química
Plasmídeos/metabolismo
Streptomyces coelicolor/metabolismo
Streptomyces lividans/metabolismo
Telômero/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); EC 2.7.7.- (DNA Primase)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170919
[Lr] Data última revisão:
170919
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170404
[St] Status:MEDLINE
[do] DOI:10.1093/nar/gkx189


  9 / 1080 MEDLINE  
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[PMID]:28338903
[Au] Autor:Tanghe M; Danneels B; Last M; Beerens K; Stals I; Desmet T
[Ad] Endereço:Centre for Synthetic Biology (CSB), Department of Biochemical and Microbial Technology, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
[Ti] Título:Disulfide bridges as essential elements for the thermostability of lytic polysaccharide monooxygenase LPMO10C from Streptomyces coelicolor.
[So] Source:Protein Eng Des Sel;30(5):401-408, 2017 May 01.
[Is] ISSN:1741-0134
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Lytic polysaccharide monooxygenases (LPMOs) are crucial components of cellulase mixtures but their stability has not yet been studied in detail, let alone been engineered for industrial applications. In this work, we have evaluated the importance of disulfide bridges for the thermodynamic stability of Streptomyces coelicolor LPMO10C. Interestingly, this enzyme was found to retain 34% of its activity after 2-h incubation at 80°C while its apparent melting temperature (Tm) is only 51°C. When its three disulfide bridges were broken, however, irreversible unfolding occurred and no residual activity could be detected after a similar heat treatment. Based on these findings, additional disulfide bridges were introduced, as predicted by computational tools (MOdelling of DIsulfide bridges in Proteins (MODiP) and Disulfide by Design (DbD)) and using the most flexible positions in the structure as target sites. Four out of 16 variants displayed an improvement in Tm, ranging from 2 to 9°C. Combining the positive mutations yielded additional improvements (up to 19°C) but aberrant unfolding patterns became apparent in some cases, resulting in a diminished capacity for heat resistance. Nonetheless, the best variant, a combination of A143C-P183C and S73C-A115C, displayed a 12°C increase in Tm and was able to retain and was able to retain no less than 60% of its activity after heat treatment.
[Mh] Termos MeSH primário: Proteínas de Bactérias/química
Dissulfetos/química
Oxigenases de Função Mista/química
Modelos Moleculares
Software
Streptomyces coelicolor/enzimologia
[Mh] Termos MeSH secundário: Estabilidade Enzimática
Temperatura Alta
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Disulfides); EC 1.- (Mixed Function Oxygenases)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170717
[Lr] Data última revisão:
170717
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170325
[St] Status:MEDLINE
[do] DOI:10.1093/protein/gzx014


  10 / 1080 MEDLINE  
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[PMID]:28293039
[Au] Autor:Martín JF; Rodríguez-García A; Liras P
[Ad] Endereço:Microbiology Area, Department of Molecular Biology, University of León, León, Spain.
[Ti] Título:The master regulator PhoP coordinates phosphate and nitrogen metabolism, respiration, cell differentiation and antibiotic biosynthesis: comparison in Streptomyces coelicolor and Streptomyces avermitilis.
[So] Source:J Antibiot (Tokyo);70(5):534-541, 2017 May.
[Is] ISSN:0021-8820
[Cp] País de publicação:Japan
[La] Idioma:eng
[Ab] Resumo:Phosphate limitation is important for production of antibiotics and other secondary metabolites in Streptomyces. Phosphate control is mediated by the two-component system PhoR-PhoP. Following phosphate depletion, PhoP stimulates expression of genes involved in scavenging, transport and mobilization of phosphate, and represses the utilization of nitrogen sources. PhoP reduces expression of genes for aerobic respiration and activates nitrate respiration genes. PhoP activates genes for teichuronic acid formation and reduces expression of genes for phosphate-rich teichoic acid biosynthesis. In Streptomyces coelicolor, PhoP repressed several differentiation and pleiotropic regulatory genes, which affects development and indirectly antibiotic biosynthesis. A new bioinformatics analysis of the putative PhoP-binding sequences in Streptomyces avermitilis was made. Many sequences in S. avermitilis genome showed high weight values and were classified according to the available genetic information. These genes encode phosphate scavenging proteins, phosphate transporters and nitrogen metabolism genes. Among of the genes highlighted in the new studies was aveR, located in the avermectin gene cluster, encoding a LAL-type regulator, and afsS, which is regulated by PhoP and AfsR. The sequence logo for S. avermitilis PHO boxes is similar to that of S. coelicolor, with differences in the weight value for specific nucleotides in the sequence.
[Mh] Termos MeSH primário: Antibacterianos/biossíntese
Proteínas de Bactérias/metabolismo
Streptomyces/metabolismo
[Mh] Termos MeSH secundário: Genes Bacterianos/genética
Genoma Bacteriano
Nitrogênio/metabolismo
Fosfatos/metabolismo
Metabolismo Secundário
Especificidade da Espécie
Streptomyces/genética
Streptomyces coelicolor/genética
Streptomyces coelicolor/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Anti-Bacterial Agents); 0 (Bacterial Proteins); 0 (Phosphates); 125360-99-8 (PhoP protein, Bacteria); N762921K75 (Nitrogen)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170620
[Lr] Data última revisão:
170620
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170316
[St] Status:MEDLINE
[do] DOI:10.1038/ja.2017.19



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