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Pesquisa : D12.776.835.725.934.374 [Categoria DeCS]
Referências encontradas : 38 [refinar]
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[PMID]:28575317
[Au] Autor:Chengguang H; Sabatini P; Brandi L; Giuliodori AM; Pon CL; Gualerzi CO
[Ad] Endereço:College of Life Sciences, Engineering Research Centre of the Chinese Ministry of Education for Bioreactor and Pharmaceutical Development, Jilin Agricultural University, Changchun 130118, Jilin, China.
[Ti] Título:Ribosomal selection of mRNAs with degenerate initiation triplets.
[So] Source:Nucleic Acids Res;45(12):7309-7325, 2017 Jul 07.
[Is] ISSN:1362-4962
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:To assess the influence of degenerate initiation triplets on mRNA recruitment by ribosomes, five mRNAs identical but for their start codon (AUG, GUG, UUG, AUU and AUA) were offered to a limiting amount of ribosomes, alone or in competition with an identical AUGmRNA bearing a mutation conferring different electrophoretic mobility to the product. Translational efficiency and competitiveness of test mRNAs toward this AUGmRNA were determined quantifying the relative amounts of the electrophoretically separated wt and mutated products synthesized in vitro and found to be influenced to different extents by the nature of their initiation triplet and by parameters such as temperature and nutrient availability in the medium. The behaviors of AUAmRNA, UUGmRNA and AUGmRNA were the same between 20 and 40°C whereas the GUG and AUUmRNAs were less active and competed poorly with the AUGmRNA, especially at low temperature. Nutrient limitation and preferential inhibition by ppGpp severely affected activity and competitiveness of all mRNAs bearing non-AUG starts, the UUGmRNA being the least affected. Overall, our data indicate that beyond these effects exclusively due to the degenerate start codons within an optimized translational initiation region, an important role is played by the context in which the rare start codons are present.
[Mh] Termos MeSH primário: Códon de Iniciação
Escherichia coli/genética
Iniciação Traducional da Cadeia Peptídica
Fator de Iniciação 1 em Procariotos/genética
RNA Mensageiro/genética
[Mh] Termos MeSH secundário: Ligação Competitiva
Escherichia coli/química
Escherichia coli/metabolismo
Cinética
Mutação
Fator de Iniciação 1 em Procariotos/metabolismo
RNA Mensageiro/metabolismo
Ribossomos/genética
Ribossomos/metabolismo
Frações Subcelulares/química
Temperatura Ambiente
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Codon, Initiator); 0 (Prokaryotic Initiation Factor-1); 0 (RNA, Messenger)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171017
[Lr] Data última revisão:
171017
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170603
[St] Status:MEDLINE
[do] DOI:10.1093/nar/gkx472


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[PMID]:27636899
[Au] Autor:Hu Y; Bernal A; Bullard JM; Zhang Y
[Ad] Endereço:Department of Chemistry, The University of Texas Rio Grande Valley, Edinburg, Texas.
[Ti] Título:Solution structure of protein synthesis initiation factor 1 from Pseudomonas aeruginosa.
[So] Source:Protein Sci;25(12):2290-2296, 2016 Dec.
[Is] ISSN:1469-896X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Pseudomonas aeruginosa is an opportunistic bacterial pathogen and a primary cause of nosocomial infection in humans. The rate of antibiotic resistance in P. aeruginosa is increasing worldwide leading to an unmet need for discovery of new chemical compounds distinctly different from present antimicrobials. Protein synthesis is an essential metabolic process and a validated target for the development of new antibiotics. Initiation factor 1 from P. aeruginosa (Pa-IF1) is the smallest of the three initiation factors that act to establish the 30S initiation complex during initiation of protein biosynthesis. Here we report the characterization and solution NMR structure of Pa-IF1. Pa-IF1 consists of a five-stranded ß-sheet with an unusual extended ß-strand at the C-terminus and one short α-helix arranged in the sequential order ß1-ß2-ß3-α1-ß4-ß5. The structure adopts a typical ß-barrel fold and contains an oligomer-binding motif. A cluster of basic residues (K39, R41, K42, K64, R66, R70, and R72) located on the surface of strands ß4 and ß5 near the short α-helix may compose the binding interface with the 30S subunit.
[Mh] Termos MeSH primário: Proteínas de Bactérias/química
Fator de Iniciação 1 em Procariotos/química
Pseudomonas aeruginosa/química
[Mh] Termos MeSH secundário: Motivos de Aminoácidos
Ressonância Magnética Nuclear Biomolecular
Domínios Proteicos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Prokaryotic Initiation Factor-1)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170713
[Lr] Data última revisão:
170713
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160917
[St] Status:MEDLINE
[do] DOI:10.1002/pro.3042


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[PMID]:26855259
[Au] Autor:Nag JK; Chahar D; Shrivastava N; Gupta CL; Bajpai P; Chandra D; Misra-Bhattacharya S
[Ad] Endereço:Division of Parasitology, CSIR-Central Drug Research Institute, BS 10/1, Sector 10, Jankipuram Extension, Sitapur Road, Lucknow (UP) 226031, India.
[Ti] Título:Functional attributes of evolutionary conserved Arg45 of Wolbachia (Brugia malayi) translation initiation factor-1.
[So] Source:Future Microbiol;11(2):195-214, 2016.
[Is] ISSN:1746-0921
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:AIM: Wolbachia is a promising antifilarial chemotherapeutic target. Translation initiation factor-1 (Tl IF-1) is an essential factor in prokaryotes. Functional characterization of Wolbachia's novel proteins/enzymes is necessary for the development of adulticidal drugs. MATERIALS & METHODS: Mutant, Wol Tl IF-1 R45D was constructed by site directed mutagenesis. Fluorimetry and size exclusion chromatography were used to determine the biophysical characteristics. Mobility shift assay and fluorescence resonance energy transfer were used to investigate the functional aspect of Wol Tl IF-1 with its mutant. RESULTS: Both wild and mutant were in monomeric native conformations. Wild exhibits nonspecific binding with ssRNA/ssDNA fragments under electrostatic conditions and showed annealing and displacement of RNA strands in comparison to mutant. CONCLUSION: Point mutation impaired RNA chaperone activity of the mutant and its interaction with nucleotides.
[Mh] Termos MeSH primário: Arginina
Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Fator de Iniciação 1 em Procariotos/genética
Fator de Iniciação 1 em Procariotos/metabolismo
Wolbachia/genética
Wolbachia/metabolismo
[Mh] Termos MeSH secundário: Animais
Proteínas de Bactérias/química
Evolução Biológica
Brugia Malayi/microbiologia
DNA/metabolismo
Ensaio de Desvio de Mobilidade Eletroforética
Seres Humanos
Mutagênese Sítio-Dirigida
Filogenia
Mutação Puntual
Fator de Iniciação 1 em Procariotos/química
Ligação Proteica
RNA/metabolismo
Alinhamento de Sequência
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Prokaryotic Initiation Factor-1); 63231-63-0 (RNA); 9007-49-2 (DNA); 94ZLA3W45F (Arginine)
[Em] Mês de entrada:1611
[Cu] Atualização por classe:161230
[Lr] Data última revisão:
161230
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160209
[St] Status:MEDLINE
[do] DOI:10.2217/fmb.15.135


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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


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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]:24929215
[Au] Autor:Nag JK; Shrivastava N; Tiwari M; Gupta Cl; Bajpai P; Chahar D; Misra-Bhattacharya S
[Ad] Endereço:Division of Parasitology, CSIR-Central Drug Research Institute, BS 10/1, Sector 10 Jankipuram Extension, Sitapur Road, Lucknow 226031, UP, India.
[Ti] Título:Wolbachia translation initiation factor-1 is copiously expressed by the adult, microfilariae and infective larvae of Brugia malayi and competitively inhibited by tetracycline.
[So] Source:Acta Trop;138:51-9, 2014 Oct.
[Is] ISSN:1873-6254
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:The intracellular alphaproteobacteria, Wolbachia, is considered to be a future antimacrofilarial drug target as it is obligatory for filarial endurance. Characterizing wolbachial proteins is necessary to understand wolbachial mechanisms and also for discovering new drug entities. Translation initiation factor-1 (Tl IF-1) is an indispensable prokaryotic factor concerned with bacterial viability. This factor is prioritized as one of the most potent antibacterial drug target. To investigate its role in filarial biology, recombinant Wol Tl IF-1 was purified on metal ion column. The factor was found folded in its monomeric native conformation, and contained a buried fluorophore. Molecular modeling revealed that the factor belonged to the Oligomer Binding family, and consisted of the highly conserved S1 domain with 81.6% of the amino acids occupying the allowed regions in Ramachandran plot. In addition, Wol Tl IF-1 exhibited selective binding to the 30S ribosomal subunit, which declined progressively with tetracycline addition. Tetracycline perturbs interaction of Thr18 and Asn32 of the factor with ribosomal protein S4. The factor was immune-localized in adult, microfilariae (Mf) and infective larvae (L3) of Brugia malayi by immunoblotting. High expression was also observed in Wolbachia within B. malayi Mf, L3 and female adult parasite along the gravid uteri by the confocal microscopy. Therefore, Wol Tl IF-1 appears to be an essential Wolbachia factor whose inhibition leads to extensive cell apoptosis and premature killing of adult worms, validating the antifilarial potential of the factor.
[Mh] Termos MeSH primário: Antibacterianos/farmacologia
Brugia Malayi/microbiologia
Fator de Iniciação 1 em Procariotos/biossíntese
Biossíntese de Proteínas/efeitos dos fármacos
Tetraciclina/farmacologia
Wolbachia/efeitos dos fármacos
Wolbachia/genética
[Mh] Termos MeSH secundário: Animais
Feminino
Perfilação da Expressão Gênica
Immunoblotting
Masculino
Camundongos Endogâmicos BALB C
Microscopia Confocal
Modelos Moleculares
Fator de Iniciação 1 em Procariotos/química
Fator de Iniciação 1 em Procariotos/isolamento & purificação
Ligação Proteica/efeitos dos fármacos
Conformação Proteica
Dobramento de Proteína
Proteínas Ribossômicas/metabolismo
Subunidades Ribossômicas Menores de Bactérias/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Anti-Bacterial Agents); 0 (Prokaryotic Initiation Factor-1); 0 (Ribosomal Proteins); 0 (ribosomal protein S4); F8VB5M810T (Tetracycline)
[Em] Mês de entrada:1505
[Cu] Atualização por classe:140906
[Lr] Data última revisão:
140906
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140615
[St] Status:MEDLINE


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[PMID]:23079772
[Au] Autor:Nag JK; Shrivastava N; Gupta J; Misra-Bhattacharya S
[Ad] Endereço:Division of Parasitology, CSIR-Central Drug Research Institute, Lucknow, Uttar Pradesh, India.
[Ti] Título:Recombinant translation initiation factor-1 of Wolbachia is an immunogenic excretory secretory protein that elicits Th2 mediated immune protection against Brugia malayi.
[So] Source:Comp Immunol Microbiol Infect Dis;36(1):25-38, 2013 Jan.
[Is] ISSN:1878-1667
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Wolbachia, the intracellular alpha-proteobacteria are required for the development, fertility and survival of filarial parasites. Wolbachia Translation initiation factor-1 (Wol Tl IF-1) is one of the factors required for Wolbachia growth and viability. In the present study, we cloned, over expressed and purified Wol Tl IF-1 that exhibited strong immuno-reactivity with various categories of bancroftian sera. Immunization with the recombinant protein resulted into significant reduction in microfilarial density (70-72%) and adult worm establishment (61-63%) in susceptible Mastomys coucha. Protection offered by Wol Tl IF-1 was found associated with humoral immune arm as observed by an increased antibody level with preponderance of IgE, IgM, IgG1 and IgG2a isotypes. The anti-Wol Tl IF-1 antibodies promoted profound adherence of peritoneal exudates cells to the surface of microfilariae and infective larvae causing cytotoxicity and their death. The present study indicates potential of recombinant Wol Tl IF-1 as a promising vaccine candidate against human lymphatic filarial infection.
[Mh] Termos MeSH primário: Brugia Malayi/imunologia
Filariose Linfática/prevenção & controle
Fator de Iniciação 1 em Procariotos/imunologia
Células Th2/imunologia
Wolbachia/imunologia
[Mh] Termos MeSH secundário: Animais
Linfócitos B/imunologia
Adesão Celular/imunologia
Clonagem Molecular
Reações Cruzadas/imunologia
Citocinas/imunologia
Citocinas/metabolismo
Citotoxicidade Imunológica
Feminino
Expressão Gênica
Antígenos de Histocompatibilidade Classe II/imunologia
Imunoglobulina E/sangue
Imunoglobulina E/imunologia
Imunoglobulina G/sangue
Imunoglobulina G/imunologia
Imunoglobulina M/sangue
Imunoglobulina M/imunologia
Ativação Linfocitária
Ativação de Macrófagos/imunologia
Macrófagos/imunologia
Masculino
Camundongos
Murinae
Fator de Iniciação 1 em Procariotos/genética
Fator de Iniciação 1 em Procariotos/secreção
Espécies Reativas de Oxigênio/metabolismo
Proteínas Recombinantes/administração & dosagem
Proteínas Recombinantes/genética
Proteínas Recombinantes/imunologia
Wolbachia/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Cytokines); 0 (Histocompatibility Antigens Class II); 0 (Immunoglobulin G); 0 (Immunoglobulin M); 0 (Prokaryotic Initiation Factor-1); 0 (Reactive Oxygen Species); 0 (Recombinant Proteins); 37341-29-0 (Immunoglobulin E)
[Em] Mês de entrada:1306
[Cu] Atualização por classe:121220
[Lr] Data última revisão:
121220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:121020
[St] Status:MEDLINE


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[PMID]:21791000
[Au] Autor:Belotserkovsky JM; Dabbs ER; Isaksson LA
[Ad] Endereço:Department of Genetics, Microbiology and Toxicology, Stockholm University, Stockholm, Sweden.
[Ti] Título:Mutations in 16S rRNA that suppress cold-sensitive initiation factor 1 affect ribosomal subunit association.
[So] Source:FEBS J;278(18):3508-17, 2011 Sep.
[Is] ISSN:1742-4658
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:A mutation in the infA gene encoding initiation factor 1 (IF1) gives rise to a cold-sensitive phenotype. An Escherichia coli strain with this mutation was used as a tool to select for second-site suppressors that compensate for the cold sensitivity and map specifically to rRNA. Several suppressor mutants with altered 16S rRNA that partially restore growth of an IF1 mutant strain in the cold were isolated and characterized. Suppressor mutations were found in helix (h)18, h32, h34 and h41 in 16S rRNA. These mutations are not clustered to any particular region in 16S rRNA and none overlap previously reported sites of interaction with IF1. While the isolated suppressors are structurally diverse, they are functionally related because all affect ribosomal subunit association in vivo. Furthermore, in vitro subunit-association experiments indicate that most of the suppressor mutations directly influence ribosomal subunit association even though none of these are confined to any of the known intersubunit bridges. These results are consistent with the model that IF1 is an rRNA chaperone that induces large-scale conformational changes in the small ribosomal subunit, and as a consequence modulates initiation of translation by affecting subunit association.
[Mh] Termos MeSH primário: Temperatura Baixa/efeitos adversos
Proteínas de Escherichia coli/metabolismo
Escherichia coli/crescimento & desenvolvimento
Mutação
Fator de Iniciação 1 em Procariotos/metabolismo
RNA Ribossômico 16S/metabolismo
Subunidades Ribossômicas/metabolismo
[Mh] Termos MeSH secundário: Substituição de Aminoácidos
Escherichia coli/genética
Escherichia coli/metabolismo
Proteínas de Escherichia coli/genética
Metiltransferases/genética
Metiltransferases/metabolismo
Modelos Moleculares
Chaperonas Moleculares/genética
Chaperonas Moleculares/metabolismo
Mutagênese Insercional
Mutagênese Sítio-Dirigida
Proteínas Mutantes/metabolismo
Conformação de Ácido Nucleico
Fator de Iniciação 1 em Procariotos/genética
Multimerização Proteica
RNA Bacteriano/química
RNA Bacteriano/genética
RNA Bacteriano/metabolismo
RNA Ribossômico 16S/química
RNA Ribossômico 16S/genética
Proteínas Recombinantes/metabolismo
Deleção de Sequência
Supressão Genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Escherichia coli Proteins); 0 (Molecular Chaperones); 0 (Mutant Proteins); 0 (Prokaryotic Initiation Factor-1); 0 (RNA, Bacterial); 0 (RNA, Ribosomal, 16S); 0 (Recombinant Proteins); EC 2.1.1.- (Methyltransferases); EC 2.1.1.- (rsmC protein, E coli)
[Em] Mês de entrada:1111
[Cu] Atualização por classe:110907
[Lr] Data última revisão:
110907
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:110728
[St] Status:MEDLINE
[do] DOI:10.1111/j.1742-4658.2011.08272.x


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[PMID]:21418143
[Au] Autor:Belotserkovsky JM; Isak GI; Isaksson LA
[Ad] Endereço:Department of Genetics, Microbiology and Toxicology, Stockholm University, Stockholm, Sweden.
[Ti] Título:Suppression of a cold-sensitive mutant initiation factor 1 by alterations in the 23S rRNA maturation region.
[So] Source:FEBS J;278(10):1745-56, 2011 May.
[Is] ISSN:1742-4658
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Genetic selection has been used to isolate second-site suppressors of a defective cold-sensitive initiation factor I (IF1) R69L mutant of Escherichia coli. The suppressor mutants specifically map to a single rRNA operon on a plasmid in a strain with all chromosomal rRNA operons deleted. Here, we describe a set of suppressor mutations that are located in the processing stem of precursor 23S rRNA. These mutations interfere with processing of the 23S rRNA termini. A lesion of RNase III also suppresses the cold sensitivity. Our results suggest that the mutant IF1 strain is perturbed at the level of ribosomal subunit association, and the suppressor mutations partially compensate for this defect by disrupting rRNA maturation. These results support the notion that IF1 is an RNA chaperone and that translation initiation is coupled to ribosomal maturation.
[Mh] Termos MeSH primário: Fator de Iniciação 1 em Procariotos/genética
RNA Ribossômico 23S/genética
[Mh] Termos MeSH secundário: Sequência de Bases
Temperatura Baixa
Escherichia coli/genética
Escherichia coli/crescimento & desenvolvimento
Dados de Sequência Molecular
Mutação
Ribonuclease III/genética
Supressão Genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Prokaryotic Initiation Factor-1); 0 (RNA, Ribosomal, 23S); EC 3.1.26.3 (Ribonuclease III)
[Em] Mês de entrada:1107
[Cu] Atualização por classe:110504
[Lr] Data última revisão:
110504
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:110323
[St] Status:MEDLINE
[do] DOI:10.1111/j.1742-4658.2011.08099.x


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[PMID]:21054500
[Au] Autor:Song WS; Ryou SM; Kim HM; Jeon CO; Kim JM; Han SH; Kim SW; Szatkiewicz JP; Cunningham PR; Lee K
[Ad] Endereço:Department of Life Sciences (BK21 program), Chung-Ang University, Seoul, Korea.
[Ti] Título:Functional investigation of residue G791 of Escherichia coli 16S rRNA: implication of initiation factor 1 in the restoration of P-site function.
[So] Source:FEMS Microbiol Lett;313(2):141-7, 2010 Dec.
[Is] ISSN:1574-6968
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Using a specialized ribosome system, previous studies have identified G791 in Escherichia coli 16S rRNA as an invariant and essential residue for ribosome function. To investigate the functional role of G791, we searched for multicopy suppressors that partially restored the protein synthesis ability of mutant ribosomes bearing a G to U substitution at position 791 (U791 ribosomes). Analyses of isolated multicopy suppressors showed that overexpression of initiation factor 1 (IF1) enhanced the protein synthesis ability of U791 ribosomes. In contrast, overexpression of initiation factor 2 (IF2) or IF3 did not enhance the protein synthesis ability of wild-type or U791 ribosomes, and overexpression of IF1 did not affect the function of wild-type or mutant ribosomes bearing nucleotide substitutions in other regions of 16S rRNA. Analyses of sucrose gradient profiles of ribosomes showed that overexpression of IF1 marginally enhanced the subunit association of U791 ribosomes and indicated lower binding affinity of U791 ribosomes to IF1. Our findings suggest the involvement of IF1 in the restoration of the P-site function that was impaired by a nucleotide substitution at residue G791.
[Mh] Termos MeSH primário: Escherichia coli/metabolismo
Fator de Iniciação 1 em Procariotos/metabolismo
Biossíntese de Proteínas
RNA Ribossômico 16S/metabolismo
Ribossomos/metabolismo
[Mh] Termos MeSH secundário: Escherichia coli/genética
Mutação Puntual
Fator de Iniciação 1 em Procariotos/genética
Fator de Iniciação 2 em Procariotos/genética
Fator de Iniciação 3 em Procariotos/genética
RNA Ribossômico 16S/genética
Subunidades Ribossômicas/metabolismo
Ribossomos/genética
Supressão Genética
[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-2); 0 (Prokaryotic Initiation Factor-3); 0 (RNA, Ribosomal, 16S)
[Em] Mês de entrada:1102
[Cu] Atualização por classe:101122
[Lr] Data última revisão:
101122
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:101109
[St] Status:MEDLINE
[do] DOI:10.1111/j.1574-6968.2010.02137.x



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