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1 / 1939

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[PMID]: 29276826 [Au] Autor: Osawa R; Kamide T; Satoh Y; Kawano Y; Ohtsu I; Dairi T [Ti] Título: Heterologous and High Production of Ergothioneine in Escherichia coli. [So] Source: J Agric Food Chem;66(5):1191-1196, 2018 Feb 07. [Is] ISSN: 1520-5118 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: Ergothioneine (ERG) is a histidine-derived thiol compound suggested to function as an antioxidant and cytoprotectant in humans. Therefore, experimental trials have been conducted applying ERG from mushrooms in dietary supplements and as a cosmetic additive. However, this method of producing ERG is expensive; therefore, alternative methods for ERG supply are required. Five Mycobacterium smegmatis genes, egtABCDE, have been confirmed to be responsible for ERG biosynthesis. This enabled us to develop practical fermentative ERG production by microorganisms. In this study, we carried out heterologous and high-level production of ERG in Escherichia coli using the egt genes from M. smegmatis. By high production of each of the Egt enzymes and elimination of bottlenecks in the substrate supply, we succeeded in constructing a production system that yielded 24 mg/L (104 µM) secreted ERG. [Mh] Termos MeSH primário: Ergotioneína/biossíntese Escherichia coli/metabolismo [Mh] Termos MeSH secundário: Antioxidantes Citoproteção Escherichia coli/genética Fermentação Técnicas de Transferência de Genes Mycobacterium smegmatis/crescimento & desenvolvimento Proteínas Recombinantes/biossíntese Transfecção [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Antioxidants); 0 (Recombinant Proteins); BDZ3DQM98W (Ergothioneine) [Em] Mês de entrada: 1802 [Cu] Atualização por classe: 180226 [Lr] Data última revisão: 180226 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 171226 [St] Status: MEDLINE [do] DOI: 10.1021/acs.jafc.7b04924

2 / 1939

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[PMID]: 28743081 [Au] Autor: Yu Z; Zhang C; Zhou M; Li Q; Li H; Duan W; Li X; Feng Y; Xie J [Ad] Endereço: Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing 400715 [Ti] Título: Mycobacterium tuberculosis PPE44 (Rv2770c) is involved in response to multiple stresses and promotes the macrophage expression of IL-12 p40 and IL-6 via the p38, ERK, and NF-κB signaling axis. [So] Source: Int Immunopharmacol;50:319-329, 2017 Sep. [Is] ISSN: 1878-1705 [Cp] País de publicação: Netherlands [La] Idioma: eng [Ab] Resumo: Tuberculosis (TB), caused by Mycobacterium tuberculosis, remains a formidable threat to global public health. The successful intracellular persistence of M. tuberculosis significantly contributes to the intractability of tuberculosis. Proline-glutamic acid (PE) and proline-proline-glutamic acid (PPE) are mycobacterial exclusive protein families that widely reported to be involved in the bacterial virulence, physiology and interaction with host. Rv2770c (PPE44), a predicted virulence factor, was up-regulated upon the infected guinea pig lungs. To investigate the role of Rv2770c, we heterologously expressed the PPE44 in the nonpathogenic fast-growing M. smegmatis strain. Subcellular location analysis demonstrated that Rv2770c is a cell wall associated protein, suggestive of a potential candidate involved in host-pathogen interaction. The Rv2770c can enhance M. smegmatis survival within macrophages and under stresses such as H O , SDS, diamide exposure, and low pH condition. M. smegmatis expressing Rv2770c is more virulent as testified by the increased death of macrophages and the increased expression of interlukin-6 (IL-6) and interlukin-12p40 (IL-12p40). Moreover, Rv2770c altered the secretion of IL-6 and IL-12p40 of macrophages via NF-κB, ERK1/2 and p38 MAPK axis. Taken together, this study implicated that Rv2770c was a virulent factor actively engaged in the interaction with host macrophage. [Mh] Termos MeSH primário: Antígenos de Bactérias/metabolismo Pulmão/patologia Macrófagos/imunologia Infecções por Micobactéria não Tuberculosa/imunologia Mycobacterium smegmatis/genética Mycobacterium tuberculosis/imunologia Tuberculose/imunologia Fatores de Virulência/metabolismo [Mh] Termos MeSH secundário: Animais Antígenos de Bactérias/genética Dano ao DNA MAP Quinases Reguladas por Sinal Extracelular/metabolismo Cobaias Interações Hospedeiro-Patógeno Seres Humanos Subunidade p40 da Interleucina-12/metabolismo Interleucina-6/metabolismo Pulmão/microbiologia Sistema de Sinalização das MAP Quinases Macrófagos/microbiologia Mycobacterium tuberculosis/genética NF-kappa B/metabolismo Transdução de Sinais Células THP-1 [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Antigens, Bacterial); 0 (Interleukin-12 Subunit p40); 0 (Interleukin-6); 0 (NF-kappa B); 0 (PPE44 protein, Mycobacterium tuberculosis); 0 (Virulence Factors); EC 2.7.11.24 (Extracellular Signal-Regulated MAP Kinases) [Em] Mês de entrada: 1802 [Cu] Atualização por classe: 180221 [Lr] Data última revisão: 180221 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170726 [St] Status: MEDLINE

3 / 1939

MEDLINE

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[PMID]: 28464471 [Au] Autor: Johnson RM; Bai G; DeMott CM; Banavali NK; Montague CR; Moon C; Shekhtman A; VanderVen B; McDonough KA [Ad] Endereço: Department of Biomedical Sciences, School of Public Health, University at Albany, SUNY, Albany, NY, USA. [Ti] Título: Chemical activation of adenylyl cyclase Rv1625c inhibits growth of Mycobacterium tuberculosis on cholesterol and modulates intramacrophage signaling. [So] Source: Mol Microbiol;105(2):294-308, 2017 Jul. [Is] ISSN: 1365-2958 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: Mycobacterium tuberculosis (Mtb) uses a complex 3', 5'-cyclic AMP (cAMP) signaling network to sense and respond to changing environments encountered during infection, so perturbation of cAMP signaling might be leveraged to disrupt Mtb pathogenesis. However, understanding of cAMP signaling pathways is hindered by the presence of at least 15 distinct adenylyl cyclases (ACs). Recently, the small molecule V-58 was shown to inhibit Mtb replication within macrophages and stimulate cAMP production in Mtb. Here we determined that V-58 rapidly and directly activates Mtb AC Rv1625c to produce high levels of cAMP regardless of the bacterial environment or growth medium. Metabolic inhibition by V-58 was carbon source dependent in Mtb and did not occur in Mycobacterium smegmatis, suggesting that V-58-mediated growth inhibition is due to interference with specific Mtb metabolic pathways rather than a generalized cAMP toxicity. Chemical stimulation of cAMP production by Mtb within macrophages also caused down regulation of TNF-α production by the macrophages, indicating a complex role for cAMP in Mtb pathogenesis. Together these studies describe a novel approach for targeted stimulation of cAMP production in Mtb, and provide new insights into the myriad roles of cAMP signaling in Mtb, particularly during Mtb's interactions with macrophages. [Mh] Termos MeSH primário: Adenilil Ciclases/genética Adenilil Ciclases/metabolismo Mycobacterium tuberculosis/metabolismo [Mh] Termos MeSH secundário: Proteínas de Bactérias/metabolismo Colesterol/metabolismo AMP Cíclico/metabolismo Regulação Bacteriana da Expressão Gênica/genética Macrófagos/microbiologia Mycobacterium smegmatis/metabolismo Transdução de Sinais [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Bacterial Proteins); 97C5T2UQ7J (Cholesterol); E0399OZS9N (Cyclic AMP); EC 4.6.1.1 (Adenylyl Cyclases) [Em] Mês de entrada: 1711 [Cu] Atualização por classe: 171128 [Lr] Data última revisão: 171128 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170503 [St] Status: MEDLINE [do] DOI: 10.1111/mmi.13701

4 / 1939

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[PMID]: 28977617 [Au] Autor: Yang K; Chang JY; Cui Z; Li X; Meng R; Duan L; Thongchol J; Jakana J; Huwe CM; Sacchettini JC; Zhang J [Ad] Endereço: Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843, USA. [Ti] Título: Structural insights into species-specific features of the ribosome from the human pathogen Mycobacterium tuberculosis. [So] Source: Nucleic Acids Res;45(18):10884-10894, 2017 Oct 13. [Is] ISSN: 1362-4962 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: Ribosomes from Mycobacterium tuberculosis (Mtb) possess species-specific ribosomal RNA (rRNA) expansion segments and ribosomal proteins (rProtein). Here, we present the near-atomic structures of the Mtb 50S ribosomal subunit and the complete Mtb 70S ribosome, solved by cryo-electron microscopy. Upon joining of the large and small ribosomal subunits, a 100-nt long expansion segment of the Mtb 23S rRNA, named H54a or the 'handle', switches interactions from with rRNA helix H68 and rProtein uL2 to with rProtein bS6, forming a new intersubunit bridge 'B9'. In Mtb 70S, bridge B9 is mostly maintained, leading to correlated motions among the handle, the L1 stalk and the small subunit in the rotated and non-rotated states. Two new protein densities were discovered near the decoding center and the peptidyl transferase center, respectively. These results provide a structural basis for studying translation in Mtb as well as developing new tuberculosis drugs. [Mh] Termos MeSH primário: Mycobacterium tuberculosis/química Ribossomos/química [Mh] Termos MeSH secundário: Microscopia Crioeletrônica Modelos Moleculares Movimento (Física) Mycobacterium smegmatis/química Inibidores da Síntese de Proteínas Proteínas Ribossômicas/química Subunidades Ribossômicas Maiores de Bactérias/química Especificidade da Espécie [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Protein Synthesis Inhibitors); 0 (Ribosomal Proteins) [Em] Mês de entrada: 1711 [Cu] Atualização por classe: 171107 [Lr] Data última revisão: 171107 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 171005 [St] Status: MEDLINE [do] DOI: 10.1093/nar/gkx785

5 / 1939

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[PMID]: 28882482 [Au] Autor: Larsen EM; Stephens DC; Clarke NH; Johnson RJ [Ad] Endereço: Department of Chemistry and Biochemistry, Butler University, 4600 Sunset Ave., Indianapolis, IN 46208, USA. [Ti] Título: Ester-prodrugs of ethambutol control its antibacterial activity and provide rapid screening for mycobacterial hydrolase activity. [So] Source: Bioorg Med Chem Lett;27(19):4544-4547, 2017 10 01. [Is] ISSN: 1464-3405 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: M. tuberculosis contains an unusually high number of serine hydrolases by proteome percentage compared to other common bacteria or humans. This letter describes a method to probe the global substrate specificity of mycobacterial serine hydrolases with ester-protected prodrugs of ethambutol, a first-line antibiotic treatment for TB. These compounds were synthesized directly from ethambutol using a selective o-acylation to yield products in high yield and purity with minimal workup. A library of derivatives was screened against M. smegmatis, a non-infectious model for M. tuberculosis, which displayed significantly lowered biological activity compared to ethambutol. Incubation with a general serine hydrolase reactivated each derivative to near-ethambutol levels, demonstrating that esterification of ethambutol should provide a simple screen for mycobacterial hydrolase activity. [Mh] Termos MeSH primário: Antibacterianos/farmacologia Inibidores Enzimáticos/farmacologia Ésteres/farmacologia Etambutol/farmacologia Hidrolases/antagonistas & inibidores Pró-Fármacos/farmacologia [Mh] Termos MeSH secundário: Antibacterianos/síntese química Antibacterianos/química Relação Dose-Resposta a Droga Avaliação Pré-Clínica de Medicamentos Inibidores Enzimáticos/síntese química Inibidores Enzimáticos/química Ésteres/síntese química Ésteres/química Etambutol/síntese química Etambutol/química Hidrolases/metabolismo Testes de Sensibilidade Microbiana Estrutura Molecular Mycobacterium smegmatis/efeitos dos fármacos Mycobacterium smegmatis/metabolismo Mycobacterium tuberculosis/efeitos dos fármacos Mycobacterium tuberculosis/metabolismo Pró-Fármacos/síntese química Pró-Fármacos/química Relação Estrutura-Atividade [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL [Nm] Nome de substância: 0 (Anti-Bacterial Agents); 0 (Enzyme Inhibitors); 0 (Esters); 0 (Prodrugs); 8G167061QZ (Ethambutol); EC 3.- (Hydrolases) [Em] Mês de entrada: 1710 [Cu] Atualização por classe: 171125 [Lr] Data última revisão: 171125 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170909 [St] Status: MEDLINE

6 / 1939

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[PMID]: 28857325 [Au] Autor: Magaña Vergara C; Kallenberg CJL; Rogasch M; Hübner CG; Song YH [Ad] Endereço: Institute of Physics, University of Luebeck, Ratzeburger Allee 160, Luebeck, 23562, Germany. [Ti] Título: A versatile vector for mycobacterial protein production with a functional minimized acetamidase regulon. [So] Source: Protein Sci;26(11):2302-2311, 2017 Nov. [Is] ISSN: 1469-896X [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: Recombinant protein expression is a prerequisite for diverse investigations of proteins at the molecular level. For targets from Mycobacterium tuberculosis it is favorable to use M. smegmatis as an expression host, a species from the same genus. In the respective shuttle vectors, target gene expression is controlled by the complex tetra-cistronic acetamidase regulon. As a result, the size of those vectors is large, rendering them of limited use, especially when the target proteins are expressed from multi-cistronic operons. Therefore, in the current work we present a versatile new expression vector in which the acetamidase regulon has been minimized by deleting the two genes amiD and amiS. We assessed the functional properties of the resulting vector pMyCA and compared it with those of the existing vector pMyNT that contains the full-length acetamidase regulon. We analyzed the growth features and protein expression patterns of M. smegmatis cultures transformed with both vectors. In addition, we created mCherry expression constructs to spectroscopically monitor the expression properties of both vectors. Our experiments showed that the minimized vector exhibited several advantages over the pMyNT vector. First, the overall yield of expressed protein is higher due to the higher yield of bacterial mass. Second, the heterologous expression was regulated more tightly, offering an expression tool for diverse target proteins. Third, it is suitable for large multi-protein complexes that are expressed from multi-cistronic operons. Additionally, our results propose a new understanding of the regulation mechanism of the acetamidase regulon with the potential to construct more optimized vectors in the future. [Mh] Termos MeSH primário: Amidoidrolases/genética Proteínas de Bactérias/genética Regulação Bacteriana da Expressão Gênica Vetores Genéticos/química Mycobacterium smegmatis/genética Mycobacterium tuberculosis/genética Regulon [Mh] Termos MeSH secundário: Amidoidrolases/metabolismo Proteínas de Bactérias/metabolismo Sequência de Bases Deleção de Genes Genes Reporter Vetores Genéticos/metabolismo Proteínas Luminescentes/genética Proteínas Luminescentes/metabolismo Mycobacterium smegmatis/metabolismo Mycobacterium tuberculosis/metabolismo Óperon Regiões Promotoras Genéticas Proteínas Recombinantes/biossíntese Proteínas Recombinantes/genética Proteínas Recombinantes/isolamento & purificação Transformação Bacteriana [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Bacterial Proteins); 0 (Luminescent Proteins); 0 (Recombinant Proteins); 0 (red fluorescent protein); EC 3.5.- (Amidohydrolases); EC 3.5.1.- (acetamidase) [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: 170901 [St] Status: MEDLINE [do] DOI: 10.1002/pro.3288

7 / 1939

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[PMID]: 28855252 [Au] Autor: Rahlwes KC; Ha SA; Motooka D; Mayfield JA; Baumoel LR; Strickland JN; Torres-Ocampo AP; Nakamura S; Morita YS [Ad] Endereço: From the Department of Microbiology, University of Massachusetts, Amherst, MA 01003. [Ti] Título: The cell envelope-associated phospholipid-binding protein LmeA is required for mannan polymerization in mycobacteria. [So] Source: J Biol Chem;292(42):17407-17417, 2017 Oct 20. [Is] ISSN: 1083-351X [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: The integrity of the distinguishing, multilaminate cell envelope surrounding mycobacteria is critical to their survival and pathogenesis. The prevalence of phosphatidylinositol mannosides in the cell envelope suggests an important role in the mycobacterial life cycle. Indeed, deletion of the gene (Δ ) encoding the first committed step in phosphatidylinositol hexamannoside biosynthesis in results in the formation of smaller colonies than wild-type colonies on Middlebrook 7H10 agar. To further investigate potential contributors to cell-envelope mannan biosynthesis while taking advantage of this colony morphology defect, we isolated spontaneous suppressor mutants of Δ that reverted to wild-type colony size. Of 22 suppressor mutants, 6 accumulated significantly shorter lipomannan or lipoarabinomannan. Genome sequencing of these mutants revealed mutations in genes involved in the lipomannan/lipoarabinomannan biosynthesis, such as those encoding the arabinosyltransferase EmbC and the mannosyltransferase MptA. Furthermore, we identified three mutants carrying a mutation in a previously uncharacterized gene, _ , that we designated Complementation of these suppressor mutants with restored the original Δ phenotypes and deletion of in wild-type resulted in smaller lipomannan, as observed in the suppressor mutants. LmeA carries a predicted N-terminal signal peptide, and density gradient fractionation and detergent extractability experiments indicated that LmeA localizes to the cell envelope. Using a lipid ELISA, we found that LmeA binds to plasma membrane phospholipids, such as phosphatidylethanolamine and phosphatidylinositol. LmeA is widespread throughout the Corynebacteriales; therefore, we concluded that LmeA is an evolutionarily conserved cell-envelope protein critical for controlling the mannan chain length of lipomannan/lipoarabinomannan. [Mh] Termos MeSH primário: Proteínas de Bactérias/metabolismo Membrana Celular/metabolismo Mananas/biossíntese Manosiltransferases/metabolismo Mycobacterium smegmatis/metabolismo [Mh] Termos MeSH secundário: Proteínas de Bactérias/genética Membrana Celular/genética Lipopolissacarídeos/biossíntese Lipopolissacarídeos/genética Mananas/genética Manosiltransferases/genética Mycobacterium smegmatis/genética Fosfolipídeos/genética Fosfolipídeos/metabolismo [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Bacterial Proteins); 0 (Lipopolysaccharides); 0 (Mannans); 0 (Phospholipids); 0 (lipoarabinomannan); 0 (lipomannan); EC 2.4.1.- (Mannosyltransferases) [Em] Mês de entrada: 1710 [Cu] Atualização por classe: 171027 [Lr] Data última revisão: 171027 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170901 [St] Status: MEDLINE [do] DOI: 10.1074/jbc.M117.804377

8 / 1939

MEDLINE

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[PMID]: 28846409 [Au] Autor: Buchieri MV; Cimino M; Rebollo-Ramirez S; Beauvineau C; Cascioferro A; Favre-Rochex S; Helynck O; Naud-Martin D; Larrouy-Maumus G; Munier-Lehmann H; Gicquel B [Ad] Endereço: Unité de Génétique Mycobactérienne, Institut Pasteur , 25 Rue du Docteur Roux, 75724 Paris Cedex 15, France. [Ti] Título: Nitazoxanide Analogs Require Nitroreduction for Antimicrobial Activity in Mycobacterium smegmatis. [So] Source: J Med Chem;60(17):7425-7433, 2017 Sep 14. [Is] ISSN: 1520-4804 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: In this study, we aimed to decipher the natural resistance mechanisms of mycobacteria against novel compounds isolated by whole-cell-based high-throughput screening (HTS). We identified active compounds using Mycobacterium aurum. Further analyses were performed to determine the resistance mechanism of M. smegmatis against one hit, 3-bromo-N-(5-nitrothiazol-2-yl)-4-propoxybenzamide (3), which turned out to be an analog of the drug nitazoxanide (1). We found that the repression of the gene nfnB coding for the nitroreductase NfnB was responsible for the natural resistance of M. smegmatis against 3. The overexpression of nfnB resulted in sensitivity of M. smegmatis to 3. This compound must be metabolized into hydroxylamine intermediate for exhibiting antibacterial activity. Thus, we describe, for the first time, the activity of a mycobacterial nitroreductase against 1 analogs, highlighting the differences in the metabolism of nitro compounds among mycobacterial species and emphasizing the potential of nitro drugs as antibacterials in various bacterial species. [Mh] Termos MeSH primário: Antibacterianos/química Antibacterianos/farmacologia Mycobacterium smegmatis/efeitos dos fármacos Mycobacterium smegmatis/enzimologia Nitrorredutases/metabolismo Tiazóis/química Tiazóis/farmacologia [Mh] Termos MeSH secundário: Regulação para Baixo Farmacorresistência Bacteriana Seres Humanos Mycobacterium/efeitos dos fármacos Mycobacterium/enzimologia Mycobacterium/genética Infecções por Mycobacterium/tratamento farmacológico Infecções por Mycobacterium/microbiologia Infecções por Micobactéria não Tuberculosa/tratamento farmacológico Infecções por Micobactéria não Tuberculosa/microbiologia Mycobacterium smegmatis/genética Nitrorredutases/genética [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Anti-Bacterial Agents); 0 (Thiazoles); EC 1.7.- (Nitroreductases); SOA12P041N (nitazoxanide) [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: 170829 [St] Status: MEDLINE [do] DOI: 10.1021/acs.jmedchem.7b00726

9 / 1939

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[PMID]: 28843989 [Au] Autor: Banda S; Cao N; Tse-Dinh YC [Ad] Endereço: Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA; Biomolecular Sciences Institute, Florida International University, Miami, FL 33199, USA. [Ti] Título: Distinct Mechanism Evolved for Mycobacterial RNA Polymerase and Topoisomerase I Protein-Protein Interaction. [So] Source: J Mol Biol;429(19):2931-2942, 2017 Sep 15. [Is] ISSN: 1089-8638 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: We report here a distinct mechanism of interaction between topoisomerase I and RNA polymerase in Mycobacterium tuberculosis and Mycobacterium smegmatis that has evolved independently from the previously characterized interaction between bacterial topoisomerase I and RNA polymerase. Bacterial DNA topoisomerase I is responsible for preventing the hyper-negative supercoiling of genomic DNA. The association of topoisomerase I with RNA polymerase during transcription elongation could efficiently relieve transcription-driven negative supercoiling. Our results demonstrate a direct physical interaction between the C-terminal domains of topoisomerase I (TopoI-CTDs) and the ß' subunit of RNA polymerase of M. smegmatis in the absence of DNA. The TopoI-CTDs in mycobacteria are evolutionarily unrelated in amino acid sequence and three-dimensional structure to the TopoI-CTD found in the majority of bacterial species outside Actinobacteria, including Escherichia coli. The functional interaction between topoisomerase I and RNA polymerase has evolved independently in mycobacteria and E. coli, with distinctively different structural elements of TopoI-CTD utilized for this protein-protein interaction. Zinc ribbon motifs in E. coli TopoI-CTD are involved in the interaction with RNA polymerase. For M. smegmatis TopoI-CTD, a 27-amino-acid tail that is rich in basic residues at the C-terminal end is responsible for the interaction with RNA polymerase. Overexpression of recombinant TopoI-CTD in M. smegmatis competed with the endogenous topoisomerase I for protein-protein interactions with RNA polymerase. The TopoI-CTD overexpression resulted in decreased survival following treatment with antibiotics and hydrogen peroxide, supporting the importance of the protein-protein interaction between topoisomerase I and RNA polymerase during stress response of mycobacteria. [Mh] Termos MeSH primário: DNA Topoisomerases Tipo I/metabolismo RNA Polimerases Dirigidas por DNA/metabolismo Mycobacterium smegmatis/enzimologia Mycobacterium tuberculosis/enzimologia Mapas de Interação de Proteínas [Mh] Termos MeSH secundário: Escherichia coli/enzimologia Ligação Proteica [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: EC 2.7.7.6 (DNA-Directed RNA Polymerases); EC 5.99.1.2 (DNA Topoisomerases, Type I) [Em] Mês de entrada: 1710 [Cu] Atualização por classe: 171002 [Lr] Data última revisão: 171002 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170828 [St] Status: MEDLINE

10 / 1939

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[PMID]: 28833086 [Au] Autor: Kundu P; Dutta D; Kumar Das A [Ad] Endereço: Department of Biotechnology, Indian Institute of Technology Kharagpur, West Bengal, India. [Ti] Título: The α1ß1 region is crucial for biofilm enhancement activity of MTC28 in Mycobacterium smegmatis. [So] Source: FEBS Lett;591(20):3333-3347, 2017 Oct. [Is] ISSN: 1873-3468 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: We show here that MTC28, a secretory antigen of 28 kDa from Mycobacterium tuberculosis, is involved in biofilm formation. The exogenous addition of MTC28 to the culture medium as well its expression in Mycobacterium smegmatis mc 155 shows an enhancement in biofilm formation, which leads to drug resistance. Structural analysis of MTC28 followed by mutational studies confirms the role of its α1ß1 region in the biofilm enhancement activity. Confocal and flow cytometry studies show that the α1ß1 region of MTC28 is crucial for binding to the M. smegmatis cell wall. The enhancement in biofilm formation due to MTC28 is also observed in M. tuberculosis H37Ra. This is the first report on the structure-function relationship of MTC28. [Mh] Termos MeSH primário: Antígenos de Bactérias/química Antígenos de Bactérias/farmacologia Proteínas de Bactérias/química Proteínas de Bactérias/farmacologia Biofilmes/efeitos dos fármacos Mycobacterium smegmatis/efeitos dos fármacos Mycobacterium tuberculosis/metabolismo [Mh] Termos MeSH secundário: Sequência de Aminoácidos Antígenos de Bactérias/genética Antituberculosos/farmacologia Proteínas de Bactérias/genética Proteínas de Bactérias/secreção Biofilmes/crescimento & desenvolvimento Parede Celular/efeitos dos fármacos Parede Celular/metabolismo Clonagem Molecular Farmacorresistência Bacteriana/genética Escherichia coli/genética Escherichia coli/metabolismo Expressão Gênica Interações Hidrofóbicas e Hidrofílicas Isoniazida/farmacologia Cinética Modelos Moleculares Mycobacterium smegmatis/genética Mycobacterium smegmatis/crescimento & desenvolvimento Mycobacterium smegmatis/metabolismo Mycobacterium tuberculosis/genética Mycobacterium tuberculosis/crescimento & desenvolvimento Ligação Proteica Conformação Proteica em alfa-Hélice Conformação Proteica em Folha beta Domínios e Motivos de Interação entre Proteínas Proteínas Recombinantes/química Proteínas Recombinantes/genética Proteínas Recombinantes/farmacologia Proteínas Recombinantes/secreção Alinhamento de Sequência Relação Estrutura-Atividade Triclosan/farmacologia [Pt] Tipo de publicação: LETTER [Nm] Nome de substância: 0 (Antigens, Bacterial); 0 (Antitubercular Agents); 0 (Bacterial Proteins); 0 (MTC28 protein, Mycobacterium tuberculosis); 0 (Recombinant Proteins); 4NM5039Y5X (Triclosan); V83O1VOZ8L (Isoniazid) [Em] Mês de entrada: 1710 [Cu] Atualização por classe: 171031 [Lr] Data última revisão: 171031 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170824 [St] Status: MEDLINE [do] DOI: 10.1002/1873-3468.12823

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