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  1 / 10 MEDLINE  
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[PMID]:28216041
[Au] Autor:Morgan JL; Acheson JF; Zimmer J
[Ad] Endereço:Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, 480 Ray C. Hunt Drive, Charlottesville, VA 22908, USA. Electronic address: jlm2qp@virginia.edu.
[Ti] Título:Structure of a Type-1 Secretion System ABC Transporter.
[So] Source:Structure;25(3):522-529, 2017 Mar 07.
[Is] ISSN:1878-4186
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Type-1 secretion systems (T1SSs) represent a widespread mode of protein secretion across the cell envelope in Gram-negative bacteria. The T1SS is composed of an inner-membrane ABC transporter, a periplasmic membrane-fusion protein, and an outer-membrane porin. These three components assemble into a complex spanning both membranes and providing a conduit for the translocation of unfolded polypeptides. We show that ATP hydrolysis and assembly of the entire T1SS complex is necessary for protein secretion. Furthermore, we present a 3.15-Å crystal structure of AaPrtD, the ABC transporter found in the Aquifex aeolicus T1SS. The structure suggests a substrate entry window just above the transporter's nucleotide binding domains. In addition, highly kinked transmembrane helices, which frame a narrow channel not observed in canonical peptide transporters, are likely involved in substrate translocation. Overall, the AaPrtD structure supports a polypeptide transport mechanism distinct from alternating access.
[Mh] Termos MeSH primário: Transportadores de Cassetes de Ligação de ATP/química
Bactérias Gram-Negativas/metabolismo
Sistemas de Secreção Tipo I/metabolismo
[Mh] Termos MeSH secundário: Transportadores de Cassetes de Ligação de ATP/metabolismo
Trifosfato de Adenosina/química
Proteínas de Bactérias/química
Cristalografia por Raios X
Bactérias Gram-Negativas/química
Hidrólise
Modelos Moleculares
Estrutura Terciária de Proteína
Sistemas de Secreção Tipo I/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Type I Secretion Systems); 8L70Q75FXE (Adenosine Triphosphate)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170823
[Lr] Data última revisão:
170823
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170221
[St] Status:MEDLINE


  2 / 10 MEDLINE  
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[PMID]:28084193
[Au] Autor:Holland IB; Peherstorfer S; Kanonenberg K; Lenders M; Reimann S; Schmitt L
[Ad] Endereço:Institute for Integrative Biology (I2BC) and Institute of Genetics and Microbiology, University Paris-Sud, Orsay 91450, France.
[Ti] Título:Type I Protein Secretion-Deceptively Simple yet with a Wide Range of Mechanistic Variability across the Family.
[So] Source:EcoSal Plus;7(1), 2016 12.
[Is] ISSN:2324-6200
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:A very large type I polypeptide begins to reel out from a ribosome; minutes later, the still unidentifiable polypeptide, largely lacking secondary structure, is now in some cases a thousand or more residues longer. Synthesis of the final hundred C-terminal residues commences. This includes the identity code, the secretion signal within the last 50 amino acids, designed to dock with a waiting ATP binding cassette (ABC) transporter. What happens next is the subject of this review, with the main, but not the only focus on hemolysin HlyA, an RTX protein toxin secreted by the type I system. Transport substrates range from small peptides to giant proteins produced by many pathogens. These molecules, without detectable cellular chaperones, overcome enormous barriers, crossing two membranes before final folding on the cell surface, involving a unique autocatalytic process.Unfolded HlyA is extruded posttranslationally, C-terminal first. The transenvelope "tunnel" is formed by HlyB (ABC transporter), HlyD (membrane fusion protein) straddling the inner membrane and periplasm and TolC (outer membrane). We present a new evaluation of the C-terminal secretion code, and the structure function of HlyD and HlyB at the heart of this nanomachine. Surprisingly, key details of the secretion mechanism are remarkably variable in the many type I secretion system subtypes. These include alternative folding processes, an apparently distinctive secretion code for each type I subfamily, and alternative forms of the ABC transporter; most remarkably, the ABC protein probably transports peptides or polypeptides by quite different mechanisms. Finally, we suggest a putative structure for the Hly-translocon, HlyB, the multijointed HlyD, and the TolC exit.
[Mh] Termos MeSH primário: Transportadores de Cassetes de Ligação de ATP/metabolismo
Bactérias/genética
Bactérias/metabolismo
Proteínas de Bactérias/metabolismo
Sistemas de Secreção Tipo I/genética
Sistemas de Secreção Tipo I/metabolismo
[Mh] Termos MeSH secundário: Transportadores de Cassetes de Ligação de ATP/genética
Proteínas da Membrana Bacteriana Externa/química
Proteínas da Membrana Bacteriana Externa/metabolismo
Proteínas de Bactérias/química
Proteínas de Bactérias/genética
Transporte Biológico
Proteínas de Transporte/química
Proteínas de Transporte/genética
Proteínas de Transporte/metabolismo
Proteínas de Escherichia coli/química
Proteínas de Escherichia coli/genética
Proteínas de Escherichia coli/metabolismo
Proteínas Hemolisinas/química
Proteínas Hemolisinas/genética
Proteínas Hemolisinas/metabolismo
Proteínas de Membrana Transportadoras/química
Proteínas de Membrana Transportadoras/genética
Proteínas de Membrana Transportadoras/metabolismo
Estrutura Secundária de Proteína
Transporte Proteico
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (ApxII toxin, bacteria); 0 (Bacterial Outer Membrane Proteins); 0 (Bacterial Proteins); 0 (Carrier Proteins); 0 (Escherichia coli Proteins); 0 (Hemolysin Proteins); 0 (HlyD protein, E coli); 0 (Hlyb protein, Bacteria); 0 (Membrane Transport Proteins); 0 (Type I Secretion Systems); 0 (tolC protein, E coli)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171126
[Lr] Data última revisão:
171126
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170114
[St] Status:MEDLINE
[do] DOI:10.1128/ecosalplus.ESP-0019-2015


  3 / 10 MEDLINE  
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[PMID]:27260307
[Au] Autor:Velásquez JC; Hidalgo AA; Villagra N; Santiviago CA; Mora GC; Fuentes JA
[Ad] Endereço:1​ Laboratorio de Genética y Patogénesis Bacteriana, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andres Bello, República 217, Santiago, Chile.
[Ti] Título:SPI-9 of Salmonella enterica serovar Typhi is constituted by an operon positively regulated by RpoS and contributes to adherence to epithelial cells in culture.
[So] Source:Microbiology;162(8):1367-78, 2016 Aug.
[Is] ISSN:1465-2080
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The genomic island 9 (SPI-9) from Salmonella enterica serovar Typhi (S. Typhi) carries three ORFs (STY2876, STY2877, STY2878) presenting 98 % identity with a type 1 secretory apparatus (T1SS), and a single ORF (STY2875) similar to a large RTX-like protein exhibiting repeated Ig domains. BapA, the Salmonella enterica serovar Enteritidis orthologous to S. Typhi STY2875, has been associated with biofilm formation, and is described as a virulence factor in mice. Preliminary in silico analyses revealed that S. Typhi STY2875 ORF has a 600 bp deletion compared with S. Enteritidis bapA, suggesting that S. Typhi STY2875 might be non-functional. At present, SPI-9 has not been studied in S. Typhi. We found that the genes constituting SPI-9 are arranged in an operon whose promoter was up-regulated in high osmolarity and low pH in a RpoS-dependent manner. All the proteins encoded by S. Typhi SPI-9 were located at the membrane fraction, consistent with their putative role as T1SS. Furthermore, SPI-9 contributed to adherence of S. Typhi to epithelial cells when bacteria were grown under high osmolarity or low pH. Under the test conditions, S. Typhi SPI-9 did not participate in biofilm formation. SPI-9 is functional in S. Typhi and encodes an adhesin induced under conditions normally found in the intestine, such as high osmolarity. Hence, this is an example of a locus that might be designated a pseudogene by computational approaches but not by direct biological assays.
[Mh] Termos MeSH primário: Aderência Bacteriana/genética
Proteínas de Bactérias/genética
Células Epiteliais/microbiologia
Ilhas Genômicas/genética
Salmonella typhi/genética
Salmonella typhi/patogenicidade
Fator sigma/genética
Sistemas de Secreção Tipo I/genética
[Mh] Termos MeSH secundário: Adesinas Bacterianas/genética
Biofilmes/crescimento & desenvolvimento
Células CACO-2
Linhagem Celular Tumoral
Escherichia coli/genética
Seres Humanos
Salmonella enteritidis/genética
Salmonella enteritidis/patogenicidade
Fatores de Virulência/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Adhesins, Bacterial); 0 (Bacterial Proteins); 0 (Sigma Factor); 0 (Type I Secretion Systems); 0 (Virulence Factors); 0 (sigma factor KatF protein, Bacteria)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171006
[Lr] Data última revisão:
171006
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160605
[St] Status:MEDLINE
[do] DOI:10.1099/mic.0.000319


  4 / 10 MEDLINE  
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[PMID]:27058787
[Au] Autor:Bumba L; Masin J; Macek P; Wald T; Motlova L; Bibova I; Klimova N; Bednarova L; Veverka V; Kachala M; Svergun DI; Barinka C; Sebo P
[Ad] Endereço:Institute of Microbiology, ASCR, v.v.i., Videnska 1083, 14220 Prague, Czech Republic.
[Ti] Título:Calcium-Driven Folding of RTX Domain ß-Rolls Ratchets Translocation of RTX Proteins through Type I Secretion Ducts.
[So] Source:Mol Cell;62(1):47-62, 2016 Apr 07.
[Is] ISSN:1097-4164
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Calcium-binding RTX proteins are equipped with C-terminal secretion signals and translocate from the Ca(2+)-depleted cytosol of Gram-negative bacteria directly into the Ca(2+)-rich external milieu, passing through the "channel-tunnel" ducts of type I secretion systems (T1SSs). Using Bordetella pertussis adenylate cyclase toxin, we solved the structure of an essential C-terminal assembly that caps the RTX domains of RTX family leukotoxins. This is shown to scaffold directional Ca(2+)-dependent folding of the carboxy-proximal RTX repeat blocks into ß-rolls. The resulting intramolecular Brownian ratchets then prevent backsliding of translocating RTX proteins in the T1SS conduits and thereby accelerate excretion of very large RTX leukotoxins from bacterial cells by a vectorial "push-ratchet" mechanism. Successive Ca(2+)-dependent and cosecretional acquisition of a functional RTX toxin structure in the course of T1SS-mediated translocation, through RTX domain folding from the C-terminal cap toward the N terminus, sets a paradigm that opens for design of virulence inhibitors of major pathogens.
[Mh] Termos MeSH primário: Toxinas Bacterianas/química
Toxinas Bacterianas/metabolismo
Cálcio/metabolismo
Bactérias Gram-Negativas/metabolismo
Sistemas de Secreção Tipo I/metabolismo
[Mh] Termos MeSH secundário: Toxina Adenilato Ciclase/química
Toxina Adenilato Ciclase/metabolismo
Animais
Bordetella pertussis/química
Bordetella pertussis/enzimologia
Linhagem Celular
Bactérias Gram-Negativas/química
Camundongos
Modelos Moleculares
Dobramento de Proteína
Estrutura Secundária de Proteína
Transporte Proteico
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Adenylate Cyclase Toxin); 0 (Bacterial Toxins); 0 (Type I Secretion Systems); SY7Q814VUP (Calcium)
[Em] Mês de entrada:1609
[Cu] Atualização por classe:160409
[Lr] Data última revisão:
160409
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160409
[St] Status:MEDLINE


  5 / 10 MEDLINE  
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[PMID]:26833388
[Au] Autor:Kim JS; Song S; Lee M; Lee S; Lee K; Ha NC
[Ad] Endereço:Department of Agricultural Biotechnology, Center for Food Safety and Toxicology, Center for Food and Bioconvergence, Research Institute for Agricultural and Life Sciences, Seoul National University, Room #200-1041, 1 Gwanak-ro, Gwanak-gu, Seoul 151-921, Republic of Korea.
[Ti] Título:Crystal Structure of a Soluble Fragment of the Membrane Fusion Protein HlyD in a Type I Secretion System of Gram-Negative Bacteria.
[So] Source:Structure;24(3):477-85, 2016 Mar 01.
[Is] ISSN:1878-4186
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The protein toxin HlyA of Escherichia coli is exported without a periplasmic intermediate by the type I secretion system (T1SS). The T1SS is composed of an inner membrane ABC transporter HlyB, an outer-membrane channel protein TolC, and a membrane fusion protein HlyD. However, the assembly of the T1SS remains to be elucidated. In this study, we determine the crystal structure of a part of the C-terminal periplasmic domain of HlyD. The long α-helical domain consisting of three α helices and a lipoyl domain was identified in the crystal structure. Based on the HlyD structure, we modeled the hexameric assembly of HlyD with a long α-helical barrel, which formed a complex with TolC in an intermeshing cogwheel-to-cogwheel manner, as observed in tripartite RND-type drug efflux pumps. These observations provide a structural blueprint for understanding the type I secretion system in pathogenic Gram-negative bacteria.
[Mh] Termos MeSH primário: Proteínas de Escherichia coli/química
Proteínas de Escherichia coli/metabolismo
Escherichia coli/metabolismo
Proteínas Hemolisinas/química
Proteínas Hemolisinas/metabolismo
Proteínas de Membrana Transportadoras/química
Proteínas de Membrana Transportadoras/metabolismo
[Mh] Termos MeSH secundário: Proteínas da Membrana Bacteriana Externa/metabolismo
Cristalografia por Raios X
Escherichia coli/química
Modelos Moleculares
Domínios Proteicos
Estrutura Secundária de Proteína
Sistemas de Secreção Tipo I/química
Sistemas de Secreção Tipo I/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Outer Membrane Proteins); 0 (Escherichia coli Proteins); 0 (Hemolysin Proteins); 0 (HlyD protein, E coli); 0 (Membrane Transport Proteins); 0 (Type I Secretion Systems); 0 (tolC protein, E coli)
[Em] Mês de entrada:1612
[Cu] Atualização por classe:161230
[Lr] Data última revisão:
161230
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160203
[St] Status:MEDLINE


  6 / 10 MEDLINE  
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[PMID]:26575364
[Au] Autor:Sankarasubramanian J; Vishnu US; Dinakaran V; Sridhar J; Gunasekaran P; Rajendhran J
[Ad] Endereço:Department of Genetics, School of Biological Sciences, Madurai Kamaraj University, Madurai, 625021, Tamil Nadu, India. jrajendhran@gmail.com.
[Ti] Título:Computational prediction of secretion systems and secretomes of Brucella: identification of novel type IV effectors and their interaction with the host.
[So] Source:Mol Biosyst;12(1):178-90, 2016 Jan.
[Is] ISSN:1742-2051
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Brucella spp. are facultative intracellular pathogens that cause brucellosis in various mammals including humans. Brucella survive inside the host cells by forming vacuoles and subverting host defence systems. This study was aimed to predict the secretion systems and the secretomes of Brucella spp. from 39 complete genome sequences available in the databases. Furthermore, an attempt was made to identify the type IV secretion effectors and their interactions with host proteins. We predicted the secretion systems of Brucella by the KEGG pathway and SecReT4. Brucella secretomes and type IV effectors (T4SEs) were predicted through genome-wide screening using JVirGel and S4TE, respectively. Protein-protein interactions of Brucella T4SEs with their hosts were analyzed by HPIDB 2.0. Genes coding for Sec and Tat pathways of secretion and type I (T1SS), type IV (T4SS) and type V (T5SS) secretion systems were identified and they are conserved in all the species of Brucella. In addition to the well-known VirB operon coding for the type IV secretion system (T4SS), we have identified the presence of additional genes showing homology with T4SS of other organisms. On the whole, 10.26 to 14.94% of total proteomes were found to be either secreted (secretome) or membrane associated (membrane proteome). Approximately, 1.7 to 3.0% of total proteomes were identified as type IV secretion effectors (T4SEs). Prediction of protein-protein interactions showed 29 and 36 host-pathogen specific interactions between Bos taurus (cattle)-B. abortus and Ovis aries (sheep)-B. melitensis, respectively. Functional characterization of the predicted T4SEs and their interactions with their respective hosts may reveal the secrets of host specificity of Brucella.
[Mh] Termos MeSH primário: Proteínas de Bactérias/secreção
Sistemas de Secreção Bacterianos/metabolismo
Brucella/metabolismo
Simulação por Computador
Modelos Biológicos
Proteoma
[Mh] Termos MeSH secundário: Animais
Sistemas de Secreção Bacterianos/genética
Brucella/genética
Interações Hospedeiro-Patógeno
Seres Humanos
Redes e Vias Metabólicas
Mapeamento de Interação de Proteínas
Mapas de Interação de Proteínas
Transporte Proteico
Sistemas de Secreção Tipo I/genética
Sistemas de Secreção Tipo I/metabolismo
Sistemas de Secreção Tipo IV
Sistemas de Secreção Tipo V/genética
Sistemas de Secreção Tipo V/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Bacterial Secretion Systems); 0 (Proteome); 0 (Type I Secretion Systems); 0 (Type IV Secretion Systems); 0 (Type V Secretion Systems)
[Em] Mês de entrada:1609
[Cu] Atualização por classe:151216
[Lr] Data última revisão:
151216
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151118
[St] Status:MEDLINE
[do] DOI:10.1039/c5mb00607d


  7 / 10 MEDLINE  
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[PMID]:26258186
[Au] Autor:Delepelaire P; Izadi-Pruneyre N; Delepierre M; Ghigo JM; Schwartz M
[Ti] Título:A tribute to Cécile Wandersman.
[So] Source:Res Microbiol;166(5):393-8, 2015 Jun.
[Is] ISSN:1769-7123
[Cp] País de publicação:France
[La] Idioma:eng
[Mh] Termos MeSH primário: Bacteriologia/história
Genética Microbiana/história
[Mh] Termos MeSH secundário: Bacteriófagos/química
Bacteriófagos/genética
França
Bactérias Gram-Negativas/metabolismo
História do Século XX
História do Século XXI
Sistemas de Secreção Tipo I
[Pt] Tipo de publicação:BIOGRAPHY; HISTORICAL ARTICLE; JOURNAL ARTICLE; PORTRAITS
[Ps] Nome de pessoa como assunto:Wandersman C
[Nm] Nome de substância:
0 (Type I Secretion Systems)
[Em] Mês de entrada:1604
[Cu] Atualização por classe:150807
[Lr] Data última revisão:
150807
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150811
[St] Status:MEDLINE


  8 / 10 MEDLINE  
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[PMID]:26030905
[Au] Autor:Kamneva OK; Poudel S; Ward NL
[Ad] Endereço:Department of Biology, Stanford University, Stanford, CA, 94305-5020, United States of America.
[Ti] Título:Proteins Related to the Type I Secretion System Are Associated with Secondary SecA_DEAD Domain Proteins in Some Species of Planctomycetes, Verrucomicrobia, Proteobacteria, Nitrospirae and Chlorobi.
[So] Source:PLoS One;10(6):e0129066, 2015.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:A number of bacteria belonging to the PVC (Planctomycetes-Verrucomicrobia-Chlamydiae) super-phylum contain unusual ribosome-bearing intracellular membranes. The evolutionary origins and functions of these membranes are unknown. Some proteins putatively associated with the presence of intracellular membranes in PVC bacteria contain signal peptides. Signal peptides mark proteins for translocation across the cytoplasmic membrane in prokaryotes, and the membrane of the endoplasmic reticulum in eukaryotes, by highly conserved Sec machinery. This suggests that proteins might be targeted to intracellular membranes in PVC bacteria via the Sec pathway. Here, we show that canonical signal peptides are significantly over-represented in proteins preferentially present in PVC bacteria possessing intracellular membranes, indicating involvement of Sec translocase in their cellular targeting. We also characterized Sec proteins using comparative genomics approaches, focusing on the PVC super-phylum. While we were unable to detect unique changes in Sec proteins conserved among membrane-bearing PVC species, we identified (1) SecA ATPase domain re-arrangements in some Planctomycetes, and (2) secondary SecA_DEAD domain proteins in the genomes of some Planctomycetes, Verrucomicrobia, Proteobacteria, Nitrospirae and Chlorobi. This is the first report of potentially duplicated SecA in Gram-negative bacteria. The phylogenetic distribution of secondary SecA_DEAD domain proteins suggests that the presence of these proteins is not related to the occurrence of PVC endomembranes. Further genomic analysis showed that secondary SecA_DEAD domain proteins are located within genomic neighborhoods that also encode three proteins possessing domains specific for the Type I secretion system.
[Mh] Termos MeSH primário: Proteínas de Bactérias/metabolismo
Chlorobi/metabolismo
Membranas Intracelulares/metabolismo
Planctomycetales/metabolismo
Proteobactérias/metabolismo
Sistemas de Secreção Tipo I/metabolismo
Verrucomicrobia/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Chlorobi/genética
Chlorobi/crescimento & desenvolvimento
Retículo Endoplasmático/metabolismo
Evolução Molecular
Variação Genética/genética
Genoma Bacteriano
Filogenia
Planctomycetales/genética
Planctomycetales/crescimento & desenvolvimento
Estrutura Terciária de Proteína
Proteobactérias/genética
Proteobactérias/crescimento & desenvolvimento
Ribossomos/metabolismo
Sistemas de Secreção Tipo I/genética
Verrucomicrobia/genética
Verrucomicrobia/crescimento & desenvolvimento
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Type I Secretion Systems)
[Em] Mês de entrada:1604
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150602
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0129066


  9 / 10 MEDLINE  
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[PMID]:25982513
[Au] Autor:D'Amato F; Eldin C; Georgiades K; Edouard S; Delerce J; Labas N; Raoult D
[Ad] Endereço:Aix Marseille Université, URMITE, UM63, CNRS 7278, IRD 198, INSERM 1095, 13005 Marseille, France. Electronic address: felicettadamato@gmail.com.
[Ti] Título:Loss of TSS1 in hypervirulent Coxiella burnetii 175, the causative agent of Q fever in French Guiana.
[So] Source:Comp Immunol Microbiol Infect Dis;41:35-41, 2015 Aug.
[Is] ISSN:1878-1667
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:In French Guiana, the unique Coxiella burnetii circulating genotype 17 causes 24% of community-acquired pneumonia, the highest prevalence ever described. To explain this unusual virulence, we performed a comparative genomic analysis of strain Cb175, which was isolated from a patient from French Guiana. Cb175 has a greater number of mutations in genes involved in metabolism compared with the Nine Mile I strain. We found a 6105bp fragment missing in Cb175, which corresponds to the Type 1 secretion systems (T1SS) hlyCABD operon region. This deletion was detected by a specific qPCR in the 8 other strains available from this territory an in none of 298C.burnetii strains from other areas and other genotypes (8/8 vs 0/298, Fisher's exact test, p<0.0000001). Loss of genes implicated in secretion systems has been observed in other epidemic bacterial strains. Thus, the virulence of Cb175 may be linked to this genome reduction.
[Mh] Termos MeSH primário: Coxiella burnetii/genética
Coxiella burnetii/patogenicidade
Deleção de Genes
Febre Q/microbiologia
Sistemas de Secreção Tipo I/genética
[Mh] Termos MeSH secundário: Coxiella burnetii/isolamento & purificação
Guiana Francesa
Variação Genética
Genoma Bacteriano
Genótipo
Seres Humanos
Mutação
Óperon
Prevalência
Reação em Cadeia da Polimerase em Tempo Real
Virulência
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Type I Secretion Systems)
[Em] Mês de entrada:1606
[Cu] Atualização por classe:150812
[Lr] Data última revisão:
150812
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150519
[St] Status:MEDLINE


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[PMID]:25800819
[Au] Autor:Luo J; Li W; Liu Z; Guo Y; Pu X; Li M
[Ad] Endereço:College of Chemistry, Sichuan University, Chengdu, Sichuan 610064, PR China. yzguo@scu.edu.cn liml@scu.edu.cn.
[Ti] Título:A sequence-based two-level method for the prediction of type I secreted RTX proteins.
[So] Source:Analyst;140(9):3048-56, 2015 May 07.
[Is] ISSN:1364-5528
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Many Gram-negative bacteria use the type I secretion system (T1SS) to translocate a wide range of substrates (type I secreted RTX proteins, T1SRPs) from the cytoplasm across the inner and outer membrane in one step to the extracellular space. Since T1SRPs play an important role in pathogen-host interactions, identifying them is crucial for a full understanding of the pathogenic mechanism of T1SS. However, experimental identification is often time-consuming and expensive. In the post-genomic era, it becomes imperative to predict new T1SRPs using information from the amino acid sequence alone when new proteins are being identified in a high-throughput mode. In this study, we report a two-level method for the first attempt to identify T1SRPs using sequence-derived features and the random forest (RF) algorithm. At the full-length sequence level, the results show that the unique feature of T1SRPs is the presence of variable numbers of the calcium-binding RTX repeats. These RTX repeats have a strong predictive power and so T1SRPs can be well distinguished from non-T1SRPs. At another level, different from that of the secretion signal, we find that a sequence segment located at the last 20-30 C-terminal amino acids may contain important signal information for T1SRP secretion because obvious differences were shown between the corresponding positions of T1SRPs and non-T1SRPs in terms of amino acid and secondary structure compositions. Using five-fold cross-validation, overall accuracies of 97% at the full-length sequence level and 89% at the secretion signal level were achieved through feature evaluation and optimization. Benchmarking on an independent dataset, our method could correctly predict 63 and 66 of 74 T1SRPs at the full-length sequence and secretion signal levels, respectively. We believe that this study will be useful in elucidating the secretion mechanism of T1SS and facilitating hypothesis-driven experimental design and validation.
[Mh] Termos MeSH primário: Proteínas de Bactérias/química
Bactérias Gram-Negativas/química
Sistemas de Secreção Tipo I/química
[Mh] Termos MeSH secundário: Algoritmos
Sequência de Aminoácidos
Inteligência Artificial
Proteínas de Bactérias/metabolismo
Bactérias Gram-Negativas/fisiologia
Infecções por Bactérias Gram-Negativas/metabolismo
Infecções por Bactérias Gram-Negativas/microbiologia
Interações Hospedeiro-Patógeno
Seres Humanos
Modelos Moleculares
Dados de Sequência Molecular
Conformação Proteica
Sistemas de Secreção Tipo I/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Type I Secretion Systems)
[Em] Mês de entrada:1512
[Cu] Atualização por classe:150421
[Lr] Data última revisão:
150421
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150325
[St] Status:MEDLINE
[do] DOI:10.1039/c5an00311c



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