Base de dados : MEDLINE
Pesquisa : D08.811.913.400.450.780 [Categoria DeCS]
Referências encontradas : 236 [refinar]
Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 24 ir para página                         

  1 / 236 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28163025
[Au] Autor:Na S; Park M; Jo I; Cha J; Ha NC
[Ad] Endereço:Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea.
[Ti] Título:Structural basis for the transglycosylase activity of a GH57-type glycogen branching enzyme from Pyrococcus horikoshii.
[So] Source:Biochem Biophys Res Commun;484(4):850-856, 2017 Mar 18.
[Is] ISSN:1090-2104
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Glycogen branching enzyme (GBE) catalyzes the formation of α-1,6-branching points during glycogenesis by cleaving α-1,4 bonds and making new α-1,6 bonds. Most GBEs belong to the glycoside hydrolase 13 family (GH13), but new GBEs in the GH57 family have been isolated from Archaea. Here, we determined the crystal structure of a GH57 GBE from the hyperthermophilic archaeon Pyrococcus horikoshii (PhGBE) at a resolution of 2.3 Å. PhGBE exhibits both α-1,6-branching activity and endo-α-1,4 hydrolytic activity. PhGBE has a central (ß/α) -barrel domain that contains an embedded helix domain and an α-helix-rich C-terminal domain. The active-site cleft is located at the interface of the central and C-terminal domains. Amino acid substitution at Trp22, which is separate from the catalytic nucleophilic residue, abolished both enzymatic activities, indicating that Trp22 might be responsible for substrate recognition. We also observed that shortening of the flexible loop near the catalytic residue changed branched chain lengths of the reaction products with increased hydrolytic activity. Taken together, our findings propose a molecular mechanism for how GH57 GBEs exhibit the two activities and where the substrate binds the enzyme.
[Mh] Termos MeSH primário: Enzima Ramificadora de 1,4-alfa-Glucana/química
Enzima Ramificadora de 1,4-alfa-Glucana/ultraestrutura
Glicogênio/química
Peptidoglicano Glicosiltransferase/química
Peptidoglicano Glicosiltransferase/ultraestrutura
Pyrococcus horikoshii/enzimologia
[Mh] Termos MeSH secundário: Sítios de Ligação
Ativação Enzimática
Ligação Proteica
Conformação Proteica
Relação Estrutura-Atividade
Especificidade por Substrato
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
9005-79-2 (Glycogen); EC 2.4.1.129 (Peptidoglycan Glycosyltransferase); EC 2.4.1.18 (1,4-alpha-Glucan Branching Enzyme)
[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:170207
[St] Status:MEDLINE


  2 / 236 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28096447
[Au] Autor:Ranjit DK; Jorgenson MA; Young KD
[Ad] Endereço:Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
[Ti] Título:PBP1B Glycosyltransferase and Transpeptidase Activities Play Different Essential Roles during the Regeneration of Rod Morphology in Escherichia coli.
[So] Source:J Bacteriol;199(7), 2017 Apr 01.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Peptidoglycan is a vital component of nearly all cell wall-bearing bacteria and is a valuable target for antibacterial therapy. However, despite decades of work, there remain important gaps in understanding how this macromolecule is synthesized and molded into a three-dimensional structure that imparts specific morphologies to individual cells. Here, we investigated the particularly enigmatic area of how peptidoglycan is synthesized and shaped during the first stages of creating cell shape , that is, in the absence of a preexisting template. We found that when lysozyme-induced (LI) spheroplasts of were allowed to resynthesize peptidoglycan, the cells divided first and then elongated to recreate a normal rod-shaped morphology. Penicillin binding protein 1B (PBP1B) was critical for the first stage of this recovery process. PBP1B synthesized peptidoglycan , and this synthesis required that PBP1B interact with the outer membrane lipoprotein LpoB. Surprisingly, when LpoB was localized improperly to the inner membrane, recovering spheroplasts synthesized peptidoglycan and divided but then propagated as amorphous spheroidal cells, suggesting that the regeneration of a normal rod shape depends on a particular spatial interaction. Similarly, spheroplasts carrying a PBP1B variant lacking transpeptidase activity or those in which PBP1A was overproduced could synthesize new peptidoglycan and divide but then grew as oddly shaped spheroids. We conclude that cell wall synthesis requires the glycosyltransferase activity of PBP1B but that PBP1B transpeptidase activity is needed to assemble cell walls with wild-type morphology. Bacterial cell wall peptidoglycan is synthesized and modified by penicillin binding proteins (PBPs), which are targeted by about half of all currently prescribed antibiotics, including penicillin and its derivatives. Because antibiotic resistance is rising, it has become increasingly urgent that we fill the gaps in our knowledge about how PBPs create and assemble this protective wall. We report here that PBP1B plays an essential role in synthesizing peptidoglycan in the absence of a preexisting template: its glycosyltransferase activity is responsible for synthesis, while its transpeptidase activity is required to construct cell walls of a specific shape. These results highlight the importance of this enzyme and distinguish its biological roles from those of other PBPs and peptidoglycan synthases.
[Mh] Termos MeSH primário: Proteínas de Escherichia coli/metabolismo
Escherichia coli/citologia
Escherichia coli/enzimologia
Regulação Bacteriana da Expressão Gênica/fisiologia
Regulação Enzimológica da Expressão Gênica/fisiologia
Proteínas de Ligação às Penicilinas/metabolismo
Peptidoglicano Glicosiltransferase/metabolismo
D-Ala-D-Ala Carboxipeptidase Tipo Serina/metabolismo
[Mh] Termos MeSH secundário: Proliferação Celular
Proteínas de Escherichia coli/genética
Mutação
Proteínas de Ligação às Penicilinas/genética
Peptidoglicano Glicosiltransferase/genética
D-Ala-D-Ala Carboxipeptidase Tipo Serina/genética
Esferoplastos/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Escherichia coli Proteins); 0 (Penicillin-Binding Proteins); EC 2.4.1.129 (Peptidoglycan Glycosyltransferase); EC 2.4.1.129 (penicillin-binding protein 1B, E coli); EC 3.4.16.4 (Serine-Type D-Ala-D-Ala Carboxypeptidase)
[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:170119
[St] Status:MEDLINE


  3 / 236 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27956425
[Au] Autor:Baker KR; Sigurðardóttir HH; Jana B; Guardabassi L
[Ad] Endereço:Department of Veterinary Disease Biology, University of Copenhagen, Frederiksberg, Denmark KrBaker@rossvet.edu.kn BJana@rossvet.edu.kn LGuardabassi@rossvet.edu.kn.
[Ti] Título:Cephem Potentiation by Inactivation of Nonessential Genes Involved in Cell Wall Biogenesis of ß-Lactamase-Producing Escherichia coli.
[So] Source:Antimicrob Agents Chemother;61(3), 2017 Mar.
[Is] ISSN:1098-6596
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Reversal of antimicrobial resistance is an appealing and largely unexplored strategy in drug discovery. The objective of this study was to identify potential targets for "helper" drugs reversing cephem resistance in strains producing ß-lactamases. A CMY-2-encoding plasmid was transferred by conjugation to seven isogenic deletion mutants exhibiting cephem hypersusceptibility. The effect of each mutation was evaluated by comparing the MICs in the wild type and the mutant harboring the same plasmid. Mutation of two genes encoding proteins involved in cell wall biosynthesis, and , restored susceptibility to cefoxitin (FOX) and reduced the MICs of cefotaxime and ceftazidime, respectively, from the resistant to the intermediate category according to clinical breakpoints. The same mutants harboring a CTX-M-1-encoding plasmid fell into the intermediate or susceptible category for all three drugs. Individual deletion of and in a clinical isolate of CTX-M-15-producing sequence type 131 (ST131) resulted in partial reversal of ceftazidime and cefepime resistance but did not reduce MICs below susceptibility breakpoints. Growth curve analysis indicated no fitness cost in a Δ mutant, whereas a Δ mutant had a 3-fold longer lag phase than the wild type, suggesting that drugs targeting DapF may display antimicrobial activity, in addition to synergizing with selected cephems. DapF appeared to be a potential FOX helper drug target candidate, since inactivation resulted in synergistic potentiation of FOX in the genetic backgrounds tested. The study showed that individual inactivation of two nonessential genes involved in cell wall biogenesis potentiates cephem activity according to drug- and strain-specific patterns.
[Mh] Termos MeSH primário: Antibacterianos/farmacologia
Cefalosporinas/farmacologia
Escherichia coli/efeitos dos fármacos
Regulação Bacteriana da Expressão Gênica
Inativação Gênica
Resistência beta-Lactâmica/efeitos dos fármacos
[Mh] Termos MeSH secundário: Parede Celular/efeitos dos fármacos
Parede Celular/metabolismo
Conjugação Genética
Escherichia coli/genética
Escherichia coli/metabolismo
Proteínas de Escherichia coli/antagonistas & inibidores
Proteínas de Escherichia coli/genética
Proteínas de Escherichia coli/metabolismo
Testes de Sensibilidade Microbiana
Proteínas de Ligação às Penicilinas/deficiência
Proteínas de Ligação às Penicilinas/genética
Peptidoglicano Glicosiltransferase/deficiência
Peptidoglicano Glicosiltransferase/genética
Plasmídeos/química
Plasmídeos/metabolismo
D-Ala-D-Ala Carboxipeptidase Tipo Serina/deficiência
D-Ala-D-Ala Carboxipeptidase Tipo Serina/genética
Resistência beta-Lactâmica/genética
beta-Lactamases/genética
beta-Lactamases/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Bacterial Agents); 0 (Cephalosporins); 0 (Escherichia coli Proteins); 0 (Penicillin-Binding Proteins); EC 2.4.1.129 (Peptidoglycan Glycosyltransferase); EC 2.4.1.129 (penicillin-binding protein 1B, E coli); EC 3.4.16.4 (Serine-Type D-Ala-D-Ala Carboxypeptidase); EC 3.5.2.- (beta-lactamase CTX-M-15); EC 3.5.2.- (beta-lactamase TEM-3); EC 3.5.2.6 (beta-Lactamases); EC 3.5.2.6 (beta-lactamase CMY-2, E coli)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170920
[Lr] Data última revisão:
170920
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161214
[St] Status:MEDLINE


  4 / 236 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27899450
[Au] Autor:King DT; Wasney GA; Nosella M; Fong A; Strynadka NC
[Ad] Endereço:From the Department of Biochemistry and Molecular Biology and Centre for Blood Research, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada.
[Ti] Título:Structural Insights into Inhibition of Escherichia coli Penicillin-binding Protein 1B.
[So] Source:J Biol Chem;292(3):979-993, 2017 Jan 20.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In Escherichia coli, the peptidoglycan cell wall is synthesized by bifunctional penicillin-binding proteins such as PBP1b that have both transpeptidase and transglycosylase activities. The PBP1b transpeptidase domain is a major target of ß-lactams, and therefore it is important to attain a detailed understanding of its inhibition. The peptidoglycan glycosyltransferase domain of PBP1b is also considered an excellent antibiotic target yet is not exploited by any clinically approved antibacterials. Herein, we adapt a pyrophosphate sensor assay to monitor PBP1b-catalyzed glycosyltransfer and present an improved crystallographic model for inhibition of the PBP1b glycosyltransferase domain by the potent substrate analog moenomycin. We elucidate the structure of a previously disordered region in the glycosyltransferase active site and discuss its implications with regards to peptidoglycan polymerization. Furthermore, we solve the crystal structures of E. coli PBP1b bound to multiple different ß-lactams in the transpeptidase active site and complement these data with gel-based competition assays to provide a detailed structural understanding of its inhibition. Taken together, these biochemical and structural data allow us to propose new insights into inhibition of both enzymatic domains in PBP1b.
[Mh] Termos MeSH primário: Escherichia coli K12/química
Proteínas de Escherichia coli/química
Proteínas de Ligação às Penicilinas/química
Peptidoglicano Glicosiltransferase/química
D-Ala-D-Ala Carboxipeptidase Tipo Serina/química
beta-Lactamas/química
[Mh] Termos MeSH secundário: Cristalografia por Raios X
Escherichia coli K12/genética
Proteínas de Escherichia coli/genética
Proteínas de Ligação às Penicilinas/genética
Peptidoglicano Glicosiltransferase/genética
Domínios Proteicos
D-Ala-D-Ala Carboxipeptidase Tipo Serina/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Escherichia coli Proteins); 0 (Penicillin-Binding Proteins); 0 (beta-Lactams); EC 2.4.1.129 (Peptidoglycan Glycosyltransferase); EC 2.4.1.129 (penicillin-binding protein 1B, E coli); EC 3.4.16.4 (Serine-Type D-Ala-D-Ala Carboxypeptidase)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170601
[Lr] Data última revisão:
170601
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161201
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M116.718403


  5 / 236 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27895129
[Au] Autor:Hausner J; Hartmann N; Jordan M; Büttner D
[Ad] Endereço:Institute of Biology, Genetics Department, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
[Ti] Título:The Predicted Lytic Transglycosylase HpaH from Xanthomonas campestris pv. vesicatoria Associates with the Type III Secretion System and Promotes Effector Protein Translocation.
[So] Source:Infect Immun;85(2), 2017 Feb.
[Is] ISSN:1098-5522
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The pathogenicity of the Gram-negative plant-pathogenic bacterium Xanthomonas campestris pv. vesicatoria depends on a type III secretion (T3S) system, which spans both bacterial membranes and translocates effector proteins into plant cells. The assembly of the T3S system presumably involves the predicted lytic transglycosylase (LT) HpaH, which is encoded adjacent to the T3S gene cluster. Bacterial LTs degrade peptidoglycan and often promote the formation of membrane-spanning macromolecular protein complexes. In the present study, we show that HpaH localizes to the bacterial periplasm and binds to peptidoglycan as well as to components of the T3S system, including the predicted periplasmic inner rod proteins HrpB1 and HrpB2 as well as the pilus protein HrpE. In vivo translocation assays revealed that HpaH promotes the translocation of various effector proteins and of early substrates of the T3S system, suggesting a general contribution of HpaH to type III-dependent protein export. Mutant studies and the analysis of reporter fusions showed that the N-terminal region of HpaH contributes to protein function and is proteolytically cleaved. The N-terminally truncated HpaH cleavage product is secreted into the extracellular milieu by a yet-unknown transport pathway, which is independent of the T3S system.
[Mh] Termos MeSH primário: Peptidoglicano Glicosiltransferase/metabolismo
Sistemas de Secreção Tipo III
Xanthomonas campestris/fisiologia
Xanthomonas vesicatoria/fisiologia
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Sequência de Bases
Códon de Iniciação
Expressão Gênica
Regulação Bacteriana da Expressão Gênica
Modelos Moleculares
Conformação Molecular
Peptidoglicano/química
Peptidoglicano/metabolismo
Peptidoglicano Glicosiltransferase/química
Peptidoglicano Glicosiltransferase/genética
Plantas/microbiologia
Ligação Proteica
Biossíntese de Proteínas
Domínios e Motivos de Interação entre Proteínas
Transporte Proteico
Proteólise
Proteínas Recombinantes de Fusão/metabolismo
Deleção de Sequência
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Codon, Initiator); 0 (Peptidoglycan); 0 (Recombinant Fusion Proteins); 0 (Type III Secretion Systems); EC 2.4.1.129 (Peptidoglycan Glycosyltransferase)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170726
[Lr] Data última revisão:
170726
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161130
[St] Status:MEDLINE


  6 / 236 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27722959
[Au] Autor:Herlihey FA; Clarke AJ
[Ad] Endereço:Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, N1G2W1, Canada.
[Ti] Título:Controlling Autolysis During Flagella Insertion in Gram-Negative Bacteria.
[So] Source:Adv Exp Med Biol;925:41-56, 2017.
[Is] ISSN:0065-2598
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The flagellum is an important macromolecular machine for many pathogenic bacteria. It is a hetero-oligomeric structure comprised of three major sub-structures: basal body, hook and thin helical filament. An important step during flagellum assembly is the localized and controlled degradation of the peptidoglycan sacculus to allow for the insertion of the rod as well as to facilitate anchoring for proper motor function. The peptidoglycan lysis events require specialized lytic enzymes, ß-N-acetylglucosaminidases and lytic transglycosylases, which differ in flagellated proteobacteria. Due to their autolytic activity, these enzymes need to be controlled in order to prevent cellular lysis. This review summarizes are current understanding of the peptidoglycan lysis events required for flagellum assembly and motility with a main focus on Gram-negative bacteria.
[Mh] Termos MeSH primário: Acetilglucosaminidase/genética
Proteínas de Bactérias/genética
Flagelos/genética
Regulação Bacteriana da Expressão Gênica
Peptidoglicano Glicosiltransferase/genética
[Mh] Termos MeSH secundário: Acetilglucosaminidase/química
Acetilglucosaminidase/metabolismo
Sequência de Aminoácidos
Proteínas de Bactérias/química
Proteínas de Bactérias/metabolismo
Bacteriólise/genética
Escherichia coli/enzimologia
Escherichia coli/genética
Escherichia coli/ultraestrutura
Flagelos/enzimologia
Flagelos/ultraestrutura
Helicobacter pylori/enzimologia
Helicobacter pylori/genética
Helicobacter pylori/ultraestrutura
Família Multigênica
Peptidoglicano/metabolismo
Peptidoglicano Glicosiltransferase/química
Peptidoglicano Glicosiltransferase/metabolismo
Pseudomonas aeruginosa/enzimologia
Pseudomonas aeruginosa/genética
Pseudomonas aeruginosa/ultraestrutura
Salmonella typhimurium/enzimologia
Salmonella typhimurium/genética
Salmonella typhimurium/ultraestrutura
Alinhamento de Sequência
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; REVIEW
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (MotA protein, Bacteria); 0 (MotB protein, Bacteria); 0 (Peptidoglycan); EC 2.4.1.129 (Peptidoglycan Glycosyltransferase); EC 3.2.1.52 (Acetylglucosaminidase)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170907
[Lr] Data última revisão:
170907
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161011
[St] Status:MEDLINE
[do] DOI:10.1007/5584_2016_52


  7 / 236 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27597434
[Au] Autor:Ragland SA; Schaub RE; Hackett KT; Dillard JP; Criss AK
[Ad] Endereço:Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, 22908, USA.
[Ti] Título:Two lytic transglycosylases in Neisseria gonorrhoeae impart resistance to killing by lysozyme and human neutrophils.
[So] Source:Cell Microbiol;19(3), 2017 Mar.
[Is] ISSN:1462-5822
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Symptomatic infection by Neisseria gonorrhoeae (Gc) produces a potent inflammatory response, resulting in a neutrophil-rich exudate. A population of Gc can survive the killing activities of neutrophils for reasons not completely understood. Unlike other Gram-negative bacteria, Gc releases monomeric peptidoglycan (PG) extracellularly, dependent on two nonessential, nonredundant lytic transglycosylases (LTs), LtgA and LtgD. PG released by LtgA and LtgD can stimulate host immune responses. We report that ΔltgAΔltgD Gc were decreased in survival in the presence of primary human neutrophils but otherwise grew equally to wild-type Gc. Adding PG monomer failed to alter ΔltgAΔltgD Gc survival. Thus, LTs protect Gc from neutrophils independently of monomer release. We found two reasons to explain decreased survival of the double LT mutant. First, ΔltgAΔltgD Gc was more sensitive to the neutrophil antimicrobial proteins lysozyme and neutrophil elastase, but not others. Sensitivity to lysozyme correlated with decreased Gc envelope integrity. Second, exposure of neutrophils to ΔltgAΔltgD Gc increased the release of neutrophil granule contents extracellularly and into Gc phagosomes. We conclude that LtgA and LtgD protect Gc from neutrophils by contributing to envelope integrity and limiting bacterial exposure to select granule-localized antimicrobial proteins. These observations are the first to link bacterial degradation by lysozyme to increased neutrophil activation.
[Mh] Termos MeSH primário: Anti-Infecciosos/metabolismo
Viabilidade Microbiana
Muramidase/metabolismo
Neisseria gonorrhoeae/enzimologia
Neutrófilos/imunologia
Peptidoglicano Glicosiltransferase/metabolismo
Peptidoglicano/metabolismo
[Mh] Termos MeSH secundário: Deleção de Genes
Seres Humanos
Neisseria gonorrhoeae/efeitos dos fármacos
Neisseria gonorrhoeae/imunologia
Neisseria gonorrhoeae/fisiologia
Peptidoglicano Glicosiltransferase/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Infective Agents); 0 (Peptidoglycan); EC 2.4.1.129 (Peptidoglycan Glycosyltransferase); EC 3.2.1.17 (Muramidase)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170731
[Lr] Data última revisão:
170731
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160907
[St] Status:MEDLINE
[do] DOI:10.1111/cmi.12662


  8 / 236 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:27941308
[Au] Autor:Takahashi Y; Takechi K; Takio S; Takano H
[Ad] Endereço:Graduate School of Science and Technology, Kumamoto University.
[Ti] Título:Both the transglycosylase and transpeptidase functions in plastid penicillin-binding protein are essential for plastid division in Physcomitrella patens.
[So] Source:Proc Jpn Acad Ser B Phys Biol Sci;92(10):499-508, 2016.
[Is] ISSN:1349-2896
[Cp] País de publicação:Japan
[La] Idioma:eng
[Ab] Resumo:Class A penicillin-binding proteins (PBPs) are active in the final step of bacterial peptidoglycan biosynthesis. They possess a transglycosylase (TG) domain to polymerize the glycan chains and a transpeptidase (TP) domain to catalyze peptide cross-linking. We reported that knockout of the Pbp gene in the moss Physcomitrella patens (ΔPpPbp) results in a macrochloroplast phenotype by affecting plastid division. Here, expression of PpPBP-GFP in ΔPpPbp restored the wild-type phenotype and GFP fluorescence was observed mainly in the periphery of each chloroplast. Stable transformants expressing Anabaena PBP with the plastid-targeting sequence, or PpPBP replacing the Anabaena TP domain exhibited partial recovery, while chloroplast number was recovered to that of wild-type plants in the transformant expressing PpPBP replacing the Anabaena TG domain. Transient expression experiments with site-directed mutagenized PpPBP showed that mutations in the conserved amino acids in both domains interfered with phenotype recovery. These results suggest that both TG and TP functions are essential for function of PpPBP in moss chloroplast division.
[Mh] Termos MeSH primário: Bryopsida/metabolismo
Proteínas de Ligação às Penicilinas/metabolismo
Peptidoglicano Glicosiltransferase/metabolismo
Peptidil Transferases/metabolismo
Plastídeos/metabolismo
[Mh] Termos MeSH secundário: Bryopsida/enzimologia
Bryopsida/genética
Teste de Complementação Genética
Mutagênese Sítio-Dirigida
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Penicillin-Binding Proteins); EC 2.3.2.12 (Peptidyl Transferases); EC 2.4.1.129 (Peptidoglycan Glycosyltransferase)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:170322
[Lr] Data última revisão:
170322
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161213
[St] Status:MEDLINE


  9 / 236 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27709766
[Au] Autor:Van't Veer IL; Leloup NO; Egan AJ; Janssen BJ; Martin NI; Vollmer W; Breukink E
[Ad] Endereço:Department of Membrane Biochemistry and Biophysics, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
[Ti] Título:Site-Specific Immobilization of the Peptidoglycan Synthase PBP1B on a Surface Plasmon Resonance Chip Surface.
[So] Source:Chembiochem;17(23):2250-2256, 2016 Dec 02.
[Is] ISSN:1439-7633
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Surface plasmon resonance (SPR) is one of the most powerful label-free methods to determine the kinetic parameters of molecular interactions in real time and in a highly sensitive way. Penicillin-binding proteins (PBPs) are peptidoglycan synthesis enzymes present in most bacteria. Established protocols to analyze interactions of PBPs by SPR involve immobilization to an ampicillin-coated chip surface (a ß-lactam antibiotic mimicking its substrate), thereby forming a covalent complex with the PBPs transpeptidase (TP) active site. However, PBP interactions measured with a substrate-bound TP domain potentially affect interactions near the TPase active site. Furthermore, in vivo PBPs are anchored in the inner membrane by an N-terminal transmembrane helix, and hence immobilization at the C-terminal TPase domain gives an orientation contrary to the in vivo situation. We designed a new procedure: immobilization of PBP by copper-free click chemistry at an azide incorporated in the N terminus. In a proof-of-principle study, we immobilized Escherichia coli PBP1B on an SPR chip surface and used this for the analysis of the well-characterized interaction of PBP1B with LpoB. The site-specific incorporation of the azide affords control over protein orientation, thereby resulting in a homogeneous immobilization on the chip surface. This method can be used to study topology-dependent interactions of any (membrane) protein.
[Mh] Termos MeSH primário: Proteínas de Escherichia coli/química
Proteínas Imobilizadas/química
Proteínas de Ligação às Penicilinas/química
Peptidoglicano Glicosiltransferase/química
D-Ala-D-Ala Carboxipeptidase Tipo Serina/química
Ressonância de Plasmônio de Superfície
[Mh] Termos MeSH secundário: Azidas/química
Azidas/metabolismo
Ciclo-Octanos/química
Ciclo-Octanos/metabolismo
Proteínas de Escherichia coli/metabolismo
Corantes Fluorescentes/química
Corantes Fluorescentes/metabolismo
Proteínas Imobilizadas/metabolismo
Modelos Moleculares
Estrutura Molecular
Proteínas de Ligação às Penicilinas/metabolismo
Peptidoglicano Glicosiltransferase/metabolismo
D-Ala-D-Ala Carboxipeptidase Tipo Serina/metabolismo
Propriedades de Superfície
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Azides); 0 (Cyclooctanes); 0 (Escherichia coli Proteins); 0 (Fluorescent Dyes); 0 (Immobilized Proteins); 0 (Penicillin-Binding Proteins); EC 2.4.1.129 (Peptidoglycan Glycosyltransferase); EC 2.4.1.129 (penicillin-binding protein 1B, E coli); EC 3.4.16.4 (Serine-Type D-Ala-D-Ala Carboxypeptidase)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170829
[Lr] Data última revisão:
170829
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161007
[St] Status:MEDLINE
[do] DOI:10.1002/cbic.201600461


  10 / 236 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:27608412
[Au] Autor:Schaub RE; Chan YA; Lee M; Hesek D; Mobashery S; Dillard JP
[Ad] Endereço:Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, WI, 53706, USA.
[Ti] Título:Lytic transglycosylases LtgA and LtgD perform distinct roles in remodeling, recycling and releasing peptidoglycan in Neisseria gonorrhoeae.
[So] Source:Mol Microbiol;102(5):865-881, 2016 Dec.
[Is] ISSN:1365-2958
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Neisseria gonorrhoeae releases peptidoglycan (PG) fragments during infection that provoke a large inflammatory response and, in pelvic inflammatory disease, this response leads to the death and sloughing of ciliated cells of the Fallopian tube. We characterized the biochemical functions and localization of two enzymes responsible for the release of proinflammatory PG fragments. The putative lytic transglycosylases LtgA and LtgD were shown to create the 1,6-anhydromuramyl moieties, and both enzymes were able to digest a small, synthetic tetrasaccharide dipeptide PG fragment into the cognate 1,6-anhydromuramyl-containing reaction products. Degradation of tetrasaccharide PG fragments by LtgA is the first demonstration of a family 1 lytic transglycosylase exhibiting this activity. Pulse-chase experiments in gonococci demonstrated that LtgA produces a larger amount of PG fragments than LtgD, and a vast majority of these fragments are recycled. In contrast, LtgD was necessary for wild-type levels of PG precursor incorporation and produced fragments predominantly released from the cell. Additionally, super-resolution microscopy established that LtgA localizes to the septum, whereas LtgD is localized around the cell. This investigation suggests a model where LtgD produces PG monomers in such a way that these fragments are released, whereas LtgA creates fragments that are mostly taken into the cytoplasm for recycling.
[Mh] Termos MeSH primário: Neisseria gonorrhoeae/metabolismo
Peptidoglicano Glicosiltransferase/metabolismo
Peptidoglicano/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Parede Celular/enzimologia
Parede Celular/metabolismo
Mutação
Neisseria gonorrhoeae/enzimologia
Neisseria gonorrhoeae/genética
Peptidoglicano Glicosiltransferase/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Peptidoglycan); EC 2.4.1.129 (Peptidoglycan Glycosyltransferase)
[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:160909
[St] Status:MEDLINE
[do] DOI:10.1111/mmi.13496



página 1 de 24 ir para página                         
   


Refinar a pesquisa
  Base de dados : MEDLINE Formulário avançado   

    Pesquisar no campo  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde