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Pesquisa : D12.776.835.725.934.750 [Categoria DeCS]
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[PMID]:28542628
[Au] Autor:Iwakura N; Yokoyama T; Quaglia F; Mitsuoka K; Mio K; Shigematsu H; Shirouzu M; Kaji A; Kaji H
[Ad] Endereço:Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Jefferson Medical College, Philadelphia, Pennsylvania, United States of America.
[Ti] Título:Chemical and structural characterization of a model Post-Termination Complex (PoTC) for the ribosome recycling reaction: Evidence for the release of the mRNA by RRF and EF-G.
[So] Source:PLoS One;12(5):e0177972, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:A model Post-Termination Complex (PoTC) used for the discovery of Ribosome Recycling Factor (RRF) was purified and characterized by cryo-electron microscopic analysis and biochemical methods. We established that the model PoTC has mostly one tRNA, at the P/E or P/P position, together with one mRNA. The structural studies were supported by the biochemical measurement of bound tRNA and mRNA. Using this substrate, we establish that the release of tRNA, release of mRNA and splitting of ribosomal subunits occur during the recycling reaction. Order of these events is tRNA release first followed by mRNA release and splitting almost simultaneously. Moreover, we demonstrate that IF3 is not involved in any of the recycling reactions but simply prevents the re-association of split ribosomal subunits. Our finding demonstrates that the important function of RRF includes the release of mRNA, which is often missed by the use of a short ORF with the Shine-Dalgarno sequence near the termination site.
[Mh] Termos MeSH primário: Escherichia coli/genética
Escherichia coli/metabolismo
Terminação Traducional da Cadeia Peptídica/genética
Fator G para Elongação de Peptídeos/metabolismo
Fatores de Terminação de Peptídeos/metabolismo
Proteínas Ribossômicas/metabolismo
Ribossomos/metabolismo
[Mh] Termos MeSH secundário: Microscopia Crioeletrônica
Fator de Iniciação 3 em Procariotos/metabolismo
RNA Mensageiro/metabolismo
RNA de Transferência/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Peptide Elongation Factor G); 0 (Peptide Termination Factors); 0 (Prokaryotic Initiation Factor-3); 0 (RNA, Messenger); 0 (Ribosomal Proteins); 0 (ribosome releasing factor); 9014-25-9 (RNA, Transfer)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170918
[Lr] Data última revisão:
170918
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170526
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0177972


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[PMID]:28320882
[Au] Autor:Ayyub SA; Dobriyal D; Varshney U
[Ad] Endereço:Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India.
[Ti] Título:Contributions of the N- and C-Terminal Domains of Initiation Factor 3 to Its Functions in the Fidelity of Initiation and Antiassociation of the Ribosomal Subunits.
[So] Source:J Bacteriol;199(11), 2017 Jun 01.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Initiation factor 3 (IF3) is one of the three conserved prokaryotic translation initiation factors essential for protein synthesis and cellular survival. Bacterial IF3 is composed of a conserved architecture of globular N- and C-terminal domains (NTD and CTD) joined by a linker region. IF3 is a ribosome antiassociation factor which also modulates selection of start codon and initiator tRNA. All the functions of IF3 have been attributed to its CTD by studies. However, the relevance of these findings has not been investigated. By generating complete and partial IF3 ( ) knockouts in and by complementation analyses using various deletion constructs, we show that while the CTD is essential for survival, the NTD is not. Polysome profiles reaffirm that CTD alone can bind to the 30S ribosomal subunit and carry out the ribosome antiassociation function. Importantly, in the absence of the NTD, bacterial growth is compromised, indicating a role for the NTD in the fitness of cellular growth. Using reporter assays for initiation, we show that the NTD plays a crucial role in the fidelity function of IF3 by avoiding (i) initiation from non-AUG codons and (ii) initiation by initiator tRNAs lacking the three highly conserved consecutive GC pairs (in the anticodon stem) known to function in concert with IF3. Initiation factor 3 regulates the fidelity of eubacterial translation initiation by ensuring the formation of an initiation complex with an mRNA bearing a canonical start codon and with an initiator tRNA at the ribosomal P site. Additionally, IF3 prevents premature association of the 50S ribosomal subunit with the 30S preinitiation complex. The significance of our work in is in demonstrating that while the C-terminal domain alone sustains for its growth, the N-terminal domain adds to the fidelity of initiation of protein synthesis and to the fitness of the bacterial growth.
[Mh] Termos MeSH primário: Proteínas de Escherichia coli/química
Proteínas de Escherichia coli/metabolismo
Escherichia coli/metabolismo
Iniciação Traducional da Cadeia Peptídica
Fator de Iniciação 3 em Procariotos/química
Fator de Iniciação 3 em Procariotos/metabolismo
Subunidades Ribossômicas/metabolismo
[Mh] Termos MeSH secundário: Códon de Iniciação/genética
Códon de Iniciação/metabolismo
Escherichia coli/química
Escherichia coli/genética
Escherichia coli/crescimento & desenvolvimento
Proteínas de Escherichia coli/genética
Domínios Proteicos
Subunidades Ribossômicas/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Codon, Initiator); 0 (Escherichia coli Proteins); 0 (Prokaryotic Initiation Factor-3)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:171109
[Lr] Data última revisão:
171109
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170322
[St] Status:MEDLINE


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[PMID]:27739094
[Au] Autor:Pathak BK; Mondal S; Barat C
[Ad] Endereço:Post Graduate Department of Biotechnology, St. Xavier's College, Kolkata, India.
[Ti] Título:Inhibition of Escherichia coli ribosome subunit dissociation by chloramphenicol and Blasticidin: a new mode of action of the antibiotics.
[So] Source:Lett Appl Microbiol;64(1):79-85, 2017 Jan.
[Is] ISSN:1472-765X
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The ability of the ribosome to assist in folding of proteins both in vitro and in vivo is well documented and is a nontranslational function of the ribosome. The interaction of the unfolded protein with the peptidyl transferase centre (PTC) of the bacterial large ribosomal subunit is followed by release of the protein in the folding competent state and rapid dissociation of ribosomal subunits. Our study demonstrates that the PTC-specific antibiotics, chloramphenicol and blasticidin S inhibit unfolded protein-mediated subunit dissociation. During post-termination stage of translation in bacteria, ribosome recycling factor (RRF) is used together with elongation factor G to recycle the 30S and 50S ribosomal subunits for the next round of translation. Ribosome dissociation mediated by RRF and induced at low magnesium concentration was also inhibited by the antibiotics indicating that the PTC antibiotics exert an associative effect on ribosomal subunits. In vivo, the antibiotics can also reduce the ribosomal degradation during carbon starvation, a process requiring ribosome subunit dissociation. This study reveals a new mode of action of the broad-spectrum antibiotics chloramphenicol and blasticidin. SIGNIFICANCE AND IMPACT OF THE STUDY: Ribosome synthesizes protein in all organisms and is the target for multiple antimicrobial agents. Our study demonstrates that chloramphenicol and blasticidin S that target the peptidyl transferase centre of the bacterial ribosome can then inhibit dissociation of 70S ribosome mediated by (i) unfolded protein, (ii) translation factors or (iii) low Mg concentrations in vitro and thereby suppresses ribosomal degradation during carbon starvation in vivo. The demonstration of this new mode of action furthers the understanding of these broad-spectrum antibiotics that differentially inhibit protein synthesis in prokaryotic and eukaryotic cells.
[Mh] Termos MeSH primário: Antibacterianos/farmacologia
Cloranfenicol/farmacologia
Escherichia coli/efeitos dos fármacos
Inibidores da Síntese de Proteínas/farmacologia
Proteínas Ribossômicas/antagonistas & inibidores
Subunidades Ribossômicas/metabolismo
[Mh] Termos MeSH secundário: Cristalografia por Raios X
Nucleosídeos/farmacologia
Fator G para Elongação de Peptídeos
Peptidil Transferases/antagonistas & inibidores
Fator de Iniciação 3 em Procariotos
Ligação Proteica
Subunidades Ribossômicas/efeitos dos fármacos
Subunidades Ribossômicas/ultraestrutura
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Bacterial Agents); 0 (Nucleosides); 0 (Peptide Elongation Factor G); 0 (Prokaryotic Initiation Factor-3); 0 (Protein Synthesis Inhibitors); 0 (Ribosomal Proteins); 0 (ribosome releasing factor); 66974FR9Q1 (Chloramphenicol); 83U64J9U23 (blasticidin S); EC 2.3.2.12 (Peptidyl Transferases)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170817
[Lr] Data última revisão:
170817
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161015
[St] Status:MEDLINE
[do] DOI:10.1111/lam.12686


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[PMID]:27662086
[Au] Autor:Hussain T; Llácer JL; Wimberly BT; Kieft JS; Ramakrishnan V
[Ad] Endereço:MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK.
[Ti] Título:Large-Scale Movements of IF3 and tRNA during Bacterial Translation Initiation.
[So] Source:Cell;167(1):133-144.e13, 2016 Sep 22.
[Is] ISSN:1097-4172
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In bacterial translational initiation, three initiation factors (IFs 1-3) enable the selection of initiator tRNA and the start codon in the P site of the 30S ribosomal subunit. Here, we report 11 single-particle cryo-electron microscopy (cryoEM) reconstructions of the complex of bacterial 30S subunit with initiator tRNA, mRNA, and IFs 1-3, representing different steps along the initiation pathway. IF1 provides key anchoring points for IF2 and IF3, thereby enhancing their activities. IF2 positions a domain in an extended conformation appropriate for capturing the formylmethionyl moiety charged on tRNA. IF3 and tRNA undergo large conformational changes to facilitate the accommodation of the formylmethionyl-tRNA (fMet-tRNA(fMet)) into the P site for start codon recognition.
[Mh] Termos MeSH primário: Códon de Iniciação
Iniciação Traducional da Cadeia Peptídica
Fator de Iniciação 3 em Procariotos/química
RNA Mensageiro/química
RNA de Transferência de Metionina/química
Subunidades Ribossômicas Menores de Bactérias/química
Thermus thermophilus/metabolismo
[Mh] Termos MeSH secundário: Microscopia Crioeletrônica
Cristalografia
Conformação Proteica
Thermus thermophilus/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Codon, Initiator); 0 (Prokaryotic Initiation Factor-3); 0 (RNA, Messenger); 0 (RNA, Transfer, Met); 0 (fMet-tRNA(fMet)); 0 (tRNA, formylmethionine-)
[Em] Mês de entrada:1612
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160924
[St] Status:MEDLINE


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[PMID]:27535792
[Au] Autor:Zheng M; Liu X; Liang S; Fu S; Qi Y; Zhao J; Shao J; An L; Yu F
[Ad] Endereço:State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China (M.Z., X.L., S.L., S.F., Y.Q., J.Z., J.S., L.A., F.Y.).
[Ti] Título:Chloroplast Translation Initiation Factors Regulate Leaf Variegation and Development.
[So] Source:Plant Physiol;172(2):1117-1130, 2016 Oct.
[Is] ISSN:1532-2548
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Chloroplast development requires the coordinated expressions of nuclear and chloroplast genomes, and both anterograde and retrograde signals exist and work together to facilitate this coordination. We have utilized the Arabidopsis yellow variegated (var2) mutant as a tool to dissect the genetic regulatory network of chloroplast development. Here, we report the isolation of a new (to our knowledge) var2 genetic suppressor locus, SUPPRESSOR OF VARIEGATION9 (SVR9). SVR9 encodes a chloroplast-localized prokaryotic type translation initiation factor 3 (IF3). svr9-1 mutant can be fully rescued by the Escherichia coli IF3 infC, suggesting that SVR9 functions as a bona fide IF3 in the chloroplast. Genetic and molecular evidence indicate that SVR9 and its close homolog SVR9-LIKE1 (SVR9L1) are functionally interchangeable and their combined activities are essential for chloroplast development and plant survival. Interestingly, we found that SVR9 and SVR9L1 are also involved in normal leaf development. Abnormalities in leaf anatomy, cotyledon venation patterns, and leaf margin development were identified in svr9-1 and mutants that are homozygous for svr9-1 and heterozygous for svr9l1-1 (svr9-1 svr9l1-1/+). Meanwhile, as indicated by the auxin response reporter DR5:GUS, auxin homeostasis was disturbed in svr9-1, svr9-1 svr9l1-1/+, and plants treated with inhibitors of chloroplast translation. Genetic analysis established that SVR9/SVR9L1-mediated leaf margin development is dependent on CUP-SHAPED COTYLEDON2 activities and is independent of their roles in chloroplast development. Together, our findings provide direct evidence that chloroplast IF3s are essential for chloroplast development and can also regulate leaf development.
[Mh] Termos MeSH primário: Proteínas de Arabidopsis/genética
Cloroplastos/genética
Folhas de Planta/genética
Fator de Iniciação 3 em Procariotos/genética
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Arabidopsis/anatomia & histologia
Arabidopsis/genética
Arabidopsis/metabolismo
Proteínas de Arabidopsis/metabolismo
Cloroplastos/metabolismo
Cotilédone/genética
Cotilédone/crescimento & desenvolvimento
Cotilédone/metabolismo
Regulação da Expressão Gênica de Plantas
Teste de Complementação Genética
Microscopia Confocal
Mutação
Filogenia
Folhas de Planta/anatomia & histologia
Folhas de Planta/crescimento & desenvolvimento
Folhas de Planta/metabolismo
Plantas Geneticamente Modificadas
Fator de Iniciação 3 em Procariotos/classificação
Fator de Iniciação 3 em Procariotos/metabolismo
Biossíntese de Proteínas
Reação em Cadeia da Polimerase Via Transcriptase Reversa
Homologia de Sequência de Aminoácidos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Arabidopsis Proteins); 0 (CUC2 protein, Arabidopsis); 0 (Prokaryotic Initiation Factor-3)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171010
[Lr] Data última revisão:
171010
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160819
[St] Status:MEDLINE


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[PMID]:27333287
[Au] Autor:Liu K; Lei Z; Yao H; Lei S; Zhao H
[Ad] Endereço:Department of General Surgery, The Second Xiangya Hospital, Central South University, Changsha, PR China.
[Ti] Título:Impact of a Eukaryotic Translation Initiation Factor 3a Polymorphism on Susceptibility to Gastric Cancer.
[So] Source:Med Princ Pract;25(5):461-5, 2016.
[Is] ISSN:1423-0151
[Cp] País de publicação:Switzerland
[La] Idioma:eng
[Ab] Resumo:OBJECTIVE: To investigate single nucleotide polymorphisms in the eukaryotic translation initiation factor 3a (eIF3a) gene and the risk for gastric cancer within the Chinese population. SUBJECTS AND METHODS: A total of 322 patients with gastric cancer were selected as the patient group and 340 non-gastric cancer patients were selected as the control group using the case-control method. Polymerase chain reaction-sequence-specific primer technology was leveraged to genotype the rs77382849 single nucleotide polymorphism in the eIF3a gene. The demographic characteristics of the study population and other exposures to risk factors were collected. Unconditional logistic regression analysis was performed to determine the association between the risk factors and gastric cancer. RESULTS: A higher frequency of the eIF3a rs77382849 GG homozygote genotype was observed in the gastric cancer patients compared with the controls (63.98 vs. 54.41%, p < 0.05). After adjustment of exposure risks, such as age, gender, smoking, and drinking, the rs77382849 single nucleotide polymorphism was still associated with susceptibility to gastric cancer. When the eIF3a rs77382849 GG homozygote genotype was used as the reference group, the GA genotype (GA vs. GG: OR = 0.545, 95% CI: 0.386-0.769, p = 0.001) and AA genotype (AA vs. GG: OR = 0.245, 95% CI: 0.072-0.836, p = 0.025) were both correlated with a significantly decreased risk for gastric cancer development. CONCLUSION: An association between eIF3a rs77382849 polymorphism and susceptibility to gastric cancer was observed in these Chinese patients.
[Mh] Termos MeSH primário: Fator de Iniciação 3 em Procariotos/genética
Neoplasias Gástricas/genética
[Mh] Termos MeSH secundário: Idoso
Idoso de 80 Anos ou mais
Grupo com Ancestrais do Continente Asiático
Estudos de Casos e Controles
China
Feminino
Predisposição Genética para Doença
Genótipo
Comportamentos Relacionados com a Saúde
Seres Humanos
Estilo de Vida
Masculino
Meia-Idade
Reação em Cadeia da Polimerase
Polimorfismo de Nucleotídeo Único
Fatores de Risco
Fatores Socioeconômicos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Prokaryotic Initiation Factor-3)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:171102
[Lr] Data última revisão:
171102
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160623
[St] Status:MEDLINE
[do] DOI:10.1159/000447741


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[PMID]:27261258
[Au] Autor:Qin B; Yamamoto H; Ueda T; Varshney U; Nierhaus KH
[Ad] Endereço:Max-Planck-Institut für molekulare Genetik, Ihnestrasse 73, D-14195 Berlin, Germany; Institut für Medizinische Physik und Biophysik, Charité, Charitéplatz 1, 10117 Berlin, Germany.
[Ti] Título:The Termination Phase in Protein Synthesis is not Obligatorily Followed by the RRF/EF-G-Dependent Recycling Phase.
[So] Source:J Mol Biol;428(18):3577-87, 2016 Sep 11.
[Is] ISSN:1089-8638
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:It is general wisdom that termination of bacterial protein synthesis is obligatorily followed by recycling governed by the factors ribosomal recycling factor (RRF), EF-G, and IF3, where the ribosome dissociates into its subunits. In contrast, a recently described 70S-scanning mode of initiation holds that after termination, scanning of 70S can be triggered by fMet-tRNA to the initiation site of a downstream cistron. Here, we analyze the apparent conflict. We constructed a bicistronic mRNA coding for luciferases and showed with a highly resolved in vitro system that the expression of the second cistron did not at all depend on the presence of active RRF. An in vivo analysis cannot be performed in a straightforward way, since RRF is essential for viability and therefore, the RRF gene cannot be knocked out. However, we found an experimental window, where the RRF amount could be reduced to below 2.5%, and in this situation, the expression of the second cistron of a bicistronic luciferase mRNA was only moderately reduced. Both in vitro and in vivo results suggested that RRF-dependent recycling is not an obligatory step after termination, in agreement with the previous findings concerning 70S-scanning initiation. In this view, recycling after termination is a special case of the general RRF function, which happens whenever fMet-tRNA is not available for triggering 70S scanning.
[Mh] Termos MeSH primário: Fator G para Elongação de Peptídeos/metabolismo
RNA Mensageiro/metabolismo
Proteínas Ribossômicas/metabolismo
Ribossomos/metabolismo
[Mh] Termos MeSH secundário: Escherichia coli/genética
Escherichia coli/metabolismo
Genes
Genes Reporter
Luciferases/análise
Luciferases/genética
Modelos Biológicos
Terminação Traducional da Cadeia Peptídica
Fator de Iniciação 3 em Procariotos/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Peptide Elongation Factor G); 0 (Prokaryotic Initiation Factor-3); 0 (RNA, Messenger); 0 (Ribosomal Proteins); 0 (ribosome releasing factor); EC 1.13.12.- (Luciferases)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170623
[Lr] Data última revisão:
170623
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160605
[St] Status:MEDLINE


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[PMID]:26668356
[Au] Autor:Ling C; Ermolenko DN
[Ad] Endereço:Department of Biochemistry and Biophysics and Center for RNA Biology, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642.
[Ti] Título:Initiation factor 2 stabilizes the ribosome in a semirotated conformation.
[So] Source:Proc Natl Acad Sci U S A;112(52):15874-9, 2015 Dec 29.
[Is] ISSN:1091-6490
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Intersubunit rotation and movement of the L1 stalk, a mobile domain of the large ribosomal subunit, have been shown to accompany the elongation cycle of translation. The initiation phase of protein synthesis is crucial for translational control of gene expression; however, in contrast to elongation, little is known about the conformational rearrangements of the ribosome during initiation. Bacterial initiation factors (IFs) 1, 2, and 3 mediate the binding of initiator tRNA and mRNA to the small ribosomal subunit to form the initiation complex, which subsequently associates with the large subunit by a poorly understood mechanism. Here, we use single-molecule FRET to monitor intersubunit rotation and the inward/outward movement of the L1 stalk of the large ribosomal subunit during the subunit-joining step of translation initiation. We show that, on subunit association, the ribosome adopts a distinct conformation in which the ribosomal subunits are in a semirotated orientation and the L1 stalk is positioned in a half-closed state. The formation of the semirotated intermediate requires the presence of an aminoacylated initiator, fMet-tRNA(fMet), and IF2 in the GTP-bound state. GTP hydrolysis by IF2 induces opening of the L1 stalk and the transition to the nonrotated conformation of the ribosome. Our results suggest that positioning subunits in a semirotated orientation facilitates subunit association and support a model in which L1 stalk movement is coupled to intersubunit rotation and/or IF2 binding.
[Mh] Termos MeSH primário: Proteínas de Escherichia coli/metabolismo
Fator de Iniciação 2 em Procariotos/metabolismo
Biossíntese de Proteínas
Ribossomos/metabolismo
[Mh] Termos MeSH secundário: Escherichia coli/genética
Escherichia coli/metabolismo
Transferência Ressonante de Energia de Fluorescência
Guanosina Trifosfato/metabolismo
Microscopia de Fluorescência
Modelos Moleculares
Conformação Molecular
Fator de Iniciação 1 em Procariotos/metabolismo
Fator de Iniciação 3 em Procariotos/metabolismo
RNA Mensageiro/genética
RNA Mensageiro/metabolismo
RNA de Transferência de Metionina/genética
RNA de Transferência de Metionina/metabolismo
Subunidades Ribossômicas/química
Subunidades Ribossômicas/metabolismo
Ribossomos/química
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Nm] Nome de substância:
0 (Escherichia coli Proteins); 0 (Prokaryotic Initiation Factor-1); 0 (Prokaryotic Initiation Factor-2); 0 (Prokaryotic Initiation Factor-3); 0 (RNA, Messenger); 0 (RNA, Transfer, Met); 86-01-1 (Guanosine Triphosphate)
[Em] Mês de entrada:1608
[Cu] Atualização por classe:161019
[Lr] Data última revisão:
161019
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151216
[St] Status:MEDLINE
[do] DOI:10.1073/pnas.1520337112


  9 / 182 MEDLINE  
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[PMID]:26338773
[Au] Autor:Goyal A; Belardinelli R; Maracci C; Milón P; Rodnina MV
[Ad] Endereço:Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
[Ti] Título:Directional transition from initiation to elongation in bacterial translation.
[So] Source:Nucleic Acids Res;43(22):10700-12, 2015 Dec 15.
[Is] ISSN:1362-4962
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The transition of the 30S initiation complex (IC) to the translating 70S ribosome after 50S subunit joining provides an important checkpoint for mRNA selection during translation in bacteria. Here, we study the timing and control of reactions that occur during 70S IC formation by rapid kinetic techniques, using a toolbox of fluorescence-labeled translation components. We present a kinetic model based on global fitting of time courses obtained with eight different reporters at increasing concentrations of 50S subunits. IF1 and IF3 together affect the kinetics of subunit joining, but do not alter the elemental rates of subsequent steps of 70S IC maturation. After 50S subunit joining, IF2-dependent reactions take place independent of the presence of IF1 or IF3. GTP hydrolysis triggers the efficient dissociation of fMet-tRNA(fMet) from IF2 and promotes the dissociation of IF2 and IF1 from the 70S IC, but does not affect IF3. The presence of non-hydrolyzable GTP analogs shifts the equilibrium towards a stable 70S-mRNA-IF1-IF2-fMet-tRNA(fMet) complex. Our kinetic analysis reveals the molecular choreography of the late stages in translation initiation.
[Mh] Termos MeSH primário: Bactérias/genética
Elongação Traducional da Cadeia Peptídica
Iniciação Traducional da Cadeia Peptídica
[Mh] Termos MeSH secundário: Escherichia coli/genética
Escherichia coli/metabolismo
Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo
Guanosina Trifosfato/metabolismo
Cinética
Fator de Iniciação 1 em Procariotos/metabolismo
Fator de Iniciação 3 em Procariotos/metabolismo
Subunidades Ribossômicas Maiores de Bactérias/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Prokaryotic Initiation Factor-1); 0 (Prokaryotic Initiation Factor-3); 37589-80-3 (Guanosine 5'-O-(3-Thiotriphosphate)); 86-01-1 (Guanosine Triphosphate)
[Em] Mês de entrada:1606
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150905
[St] Status:MEDLINE
[do] DOI:10.1093/nar/gkv869


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[PMID]:25743365
[Au] Autor:Sun BG; Hu YH
[Ad] Endereço:Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, People's Republic of China.
[Ti] Título:Evaluation of potential internal references for quantitative real-time RT-PCR normalization of gene expression in red drum (Sciaenops ocellatus).
[So] Source:Fish Physiol Biochem;41(3):695-704, 2015 Jun.
[Is] ISSN:1573-5168
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) has been used extensively for studying gene expression in diverse organisms including fish. In this study, with an aim to identify reliable reference genes for qRT-PCR in red drum (Sciaenops ocellatus), an economic fish species, we determined the expression stability of seven housekeeping genes in healthy and bacterium-infected red drum. Each of the selected candidate genes was amplified by qRT-PCR from the brain, gill, heart, intestine, kidney, liver, muscle, and spleen of red drum infected with or without a bacterial pathogen for 12 and 48 h. The mRNA levels of the genes were analyzed with the geNorm and NormFinder algorithms. The results showed that in the absence of bacterial infection, translation initiation factor 3, NADH dehydrogenase 1, and QM-like protein may be used together as internal references across the eight examined tissues. Bacterial infection caused variations in the rankings of the most stable genes in a tissue-dependent manner. For all tissues, two genes sufficed for reliable normalization at both 12 and 48 h post-infection. However, the optimal gene pairs differed among tissues and, for four of the examined eight tissues, between infection points. These results indicate that when studying gene expression in red drum under conditions of bacterial infection, the optimal reference genes should be selected on the basis of tissue type and, for accurate normalization, infection stage.
[Mh] Termos MeSH primário: Regulação da Expressão Gênica/genética
Genes Essenciais/genética
Perciformes/genética
RNA Mensageiro/genética
Reação em Cadeia da Polimerase em Tempo Real/veterinária
[Mh] Termos MeSH secundário: Animais
Encéfalo/metabolismo
Complexo I de Transporte de Elétrons/genética
Complexo I de Transporte de Elétrons/metabolismo
Brânquias/metabolismo
Músculo Esquelético/metabolismo
Fator de Iniciação 3 em Procariotos/genética
Fator de Iniciação 3 em Procariotos/metabolismo
Reação em Cadeia da Polimerase em Tempo Real/métodos
Reação em Cadeia da Polimerase em Tempo Real/normas
Padrões de Referência
Vísceras/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Prokaryotic Initiation Factor-3); 0 (RNA, Messenger); EC 1.6.5.3 (Electron Transport Complex I)
[Em] Mês de entrada:1602
[Cu] Atualização por classe:171020
[Lr] Data última revisão:
171020
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150307
[St] Status:MEDLINE
[do] DOI:10.1007/s10695-015-0039-8



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