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Alireza Hadizadeh Tasbiti, Shamsi Yari, Mostafa Ghanei, Seyed Davar Siadat, Amir Amanzadeh, Payam Tabarsi, Keyvan Saeedfar, Ahmadreza Bahrmand
OBJECTIVE: Tuberculosis (TB) is a devastating disease that remains a major health threat worldwide. The appearance of Mycobacterium tuberculosis strains resistance to current antibiotics is a growing problem, both in the third world and in developed countries. Completion of genomic sequencing of M. tuberculosis provides a strong foundation for subsequent identification of proteins to aid the understanding of protein function and the discovery of new drug targets or a TB vaccine. This study employed a proteomics approach to identify proteins from antibiotic resistant M...
December 2016: International Journal of Mycobacteriology
Georgia Maciel Dias de Moraes, Louricélia Rodrigues de Abreu, Antônio Silvio do Egito, Hévila Oliveira Salles, Liana Maria Ferreira da Silva, Luís Augusto Nero, Svetoslav Dimitrov Todorov, Karina Maria Olbrich Dos Santos
The search for probiotic candidates among lactic acid bacteria (LAB) isolated from food may uncover new strains with promising health and technological properties. Lactobacillus mucosae strains attracted recent research attention due to their ability to adhere to intestinal mucus and to inhibit pathogens in the gastrointestinal tract, both related to a probiotic potential. Properties of interest and safety aspects of three Lb. mucosae strains (CNPC006, CNPC007, and CNPC009) isolated from goat milk were investigated employing in vitro tests...
December 10, 2016: Probiotics and Antimicrobial Proteins
Atul Kumar Agrawal, Rajeev Ranjan, Sharat Chandra, Tofan Kumar Rout, Amit Misra, Thota Jagadeshwar Reddy
Host-pathogen dialectics in tuberculosis (TB) via DNA-protein interactions are emerging. We investigated whether proteins produced by Mycobacterium tuberculosis (Mtb) could translocate to the host nucleus. Using lysates of nuclei purified from Mtb-infected THP-1-derived macrophages, we identified at least 15 proteins of Mtb-origin by electrophoretic and chromatographic separation and mass spectrometry. Western blotting confirmed time-dependent accumulation of Mtb EF-Tu, GroEL, GroES and MtrA in the host nucleus...
December 2016: Tuberculosis
Ka-Weng Ieong, Ülkü Uzun, Maria Selmer, Måns Ehrenberg
Aminoacyl-tRNAs (aa-tRNAs) are selected by the messenger RNA programmed ribosome in ternary complex with elongation factor Tu (EF-Tu) and GTP and then, again, in a proofreading step after GTP hydrolysis on EF-Tu. We use tRNA mutants with different affinities for EF-Tu to demonstrate that proofreading of aa-tRNAs occurs in two consecutive steps. First, aa-tRNAs in ternary complex with EF-Tu·GDP are selected in a step where the accuracy increases linearly with increasing aa-tRNA affinity to EF-Tu. Then, following dissociation of EF-Tu·GDP from the ribosome, the accuracy is further increased in a second and apparently EF-Tu-independent step...
November 29, 2016: Proceedings of the National Academy of Sciences of the United States of America
Jeffrey K Noel, Paul C Whitford
It has long been recognized that the thermodynamics of mRNA-tRNA base pairing is insufficient to explain the high fidelity and efficiency of aminoacyl-tRNA (aa-tRNA) selection by the ribosome. To rationalize this apparent inconsistency, Hopfield proposed that the ribosome may improve accuracy by utilizing a multi-step kinetic proofreading mechanism. While biochemical, structural and single-molecule studies have provided a detailed characterization of aa-tRNA selection, there is a limited understanding of how the physical-chemical properties of the ribosome enable proofreading...
October 31, 2016: Nature Communications
Kuo-Hsun Chiu, Ling-Hui Wang, Tsung-Ting Tsai, Huan-Yao Lei, Pao-Chi Liao
The secreted proteins of bacteria are usually accompanied by virulence factors, which can cause inflammation and damage host cells. Identifying the secretomes arising from the interactions of bacteria and host cells could, therefore, increase understanding of the mechanisms during initial pathogenesis. The present study used a host-pathogen coculture system of Helicobacter pylori and monocytes (THP-1 cells) to investigate the secreted proteins associated with initial H. pylori pathogenesis. The secreted proteins from the conditioned media from H...
October 20, 2016: Journal of Proteome Research
Malgorzata Dobosz-Bartoszek, Mark H Pinkerton, Zbyszek Otwinowski, Srinivas Chakravarthy, Dieter Söll, Paul R Copeland, Miljan Simonović
Selenocysteine is the only proteinogenic amino acid encoded by a recoded in-frame UGA codon that does not operate as the canonical opal stop codon. A specialized translation elongation factor, eEFSec in eukaryotes and SelB in prokaryotes, promotes selenocysteine incorporation into selenoproteins by a still poorly understood mechanism. Our structural and biochemical results reveal that four domains of human eEFSec fold into a chalice-like structure that has similar binding affinities for GDP, GTP and other guanine nucleotides...
October 6, 2016: Nature Communications
Malick Mbengue, Gildas Bourdais, Fabio Gervasi, Martina Beck, Ji Zhou, Thomas Spallek, Sebastian Bartels, Thomas Boller, Takashi Ueda, Hannah Kuhn, Silke Robatzek
Sensing of potential pathogenic bacteria is of critical importance for immunity. In plants, this involves plasma membrane-resident pattern recognition receptors, one of which is the FLAGELLIN SENSING 2 (FLS2) receptor kinase. Ligand-activated FLS2 receptors are internalized into endosomes. However, the extent to which these spatiotemporal dynamics are generally present among pattern recognition receptors (PRRs) and their regulation remain elusive. Using live-cell imaging, we show that at least three other receptor kinases associated with plant immunity, PEP RECEPTOR 1/2 (PEPR1/2) and EF-TU RECEPTOR (EFR), internalize in a ligand-specific manner...
September 27, 2016: Proceedings of the National Academy of Sciences of the United States of America
Naile Dame-Teixeira, Clarissa Cavalcanti Fatturi Parolo, Marisa Maltz, Aradhna Tugnait, Deirdre Devine, Thuy Do
BACKGROUND: The studies of the distribution of Actinomyces spp. on carious and non-carious root surfaces have not been able to confirm the association of these bacteria with root caries, although they were extensively implicated as a prime suspect in root caries. OBJECTIVE: The aim of this study was to observe the gene expression of Actinomyces spp. in the microbiota of root surfaces with and without caries. DESIGN: The oral biofilms from exposed sound root surface (SRS; n=10) and active root caries (RC; n=30) samples were collected...
2016: Journal of Oral Microbiology
Caroline Maria Marcos, Haroldo Cesar de Oliveira, Julhiany de Fátima da Silva, Patricia Akemi Assato, Daniella Sayuri Yamazaki, Rosângela Aparecida Moraes da Silva, Cláudia Tavares Santos, Norival Alves Santos-Filho, Deivys Leandro Portuondo, Maria José Soares Mendes-Giannini, Ana Marisa Fusco-Almeida
Paracoccidioides spp., which are temperature-dependent dimorphic fungi, are responsible for the most prevalent human systemic mycosis in Latin America, the paracoccidioidomycosis. The aim of this study was to characterise the involvement of elongation factor Tu (EF-Tu) in Paracoccidioides brasiliensis-host interaction. Adhesive properties were examined using recombinant PbEF-Tu proteins and the respective polyclonal anti-rPbEF-Tu antibody. Immunogold analysis demonstrated the surface location of EF-Tu in P...
November 2016: FEMS Yeast Research
Evelina Ines De Laurentiis, Evan Mercier, Hans-Joachim Wieden
Little is known about the conservation of critical kinetic parameters and the mechanistic strategies of elongation factor (EF) Ts-catalyzed nucleotide exchange in EF-Tu in bacteria and particularly in clinically relevant pathogens. EF-Tu from the clinically relevant pathogen Pseudomonas aeruginosa shares over 84% sequence identity with the corresponding elongation factor from Escherichia coli Interestingly, the functionally closely linked EF-Ts only shares 55% sequence identity. To identify any differences in the nucleotide binding properties, as well as in the EF-Ts-mediated nucleotide exchange reaction, we performed a comparative rapid kinetics and mutagenesis analysis of the nucleotide exchange mechanism for both the E...
October 28, 2016: Journal of Biological Chemistry
Ryoji Funadani, Yoichiro Sogame, Katsuhiko Kojima, Toshikazu Takeshita, Keisuke Yamamoto, Tomoya Tsujizono, Futoshi Suizu, Seiji Miyata, Ken-Ichi Yagyu, Tomohiko Suzuki, Mikihiko Arikawa, Tatsuomi Matsuoka
The cyst wall of the resting cyst of the ciliated protozoan Colpoda cucullus (Nag-1 strain) is composed of several layers of endocyst, a single layer of ectocyst associated with a mucous layer and lepidosomes composed of a fibrous or crystal-like structure. SDS-PAGE showed that the ectocyst associated with lepidosomes and mucous materials contained proteins corresponding to 27 kDa, 31 kDa, 45 kDa and smear bands ranging from 50 to 60 kDa. LC-MS/MS of these proteins revealed that the 45-kDa protein (p45) was elongation factor Tu (EF-Tu)...
August 28, 2016: FEMS Microbiology Letters
Giulia Degiacomi, Yoann Personne, Guillaume Mondésert, Xueliang Ge, Chandra Sekhar Mandava, Ruben C Hartkoorn, Francesca Boldrin, Pavitra Goel, Kristin Peisker, Andrej Benjak, Maria Belén Barrio, Marcello Ventura, Amanda C Brown, Véronique Leblanc, Armin Bauer, Suparna Sanyal, Stewart T Cole, Sophie Lagrange, Tanya Parish, Riccardo Manganelli
The lack of proper treatment for serious infectious diseases due to the emergence of multidrug resistance reinforces the need for the discovery of novel antibiotics. This is particularly true for tuberculosis (TB) for which 3.7% of new cases and 20% of previously treated cases are estimated to be caused by multi-drug resistant strains. In addition, in the case of TB, which claimed 1.5 million lives in 2014, the treatment of the least complicated, drug sensitive cases is lengthy and disagreeable. Therefore, new drugs with novel targets are urgently needed to control resistant Mycobacterium tuberculosis strains...
September 2016: Tuberculosis
Fei Jiang, Jinyan He, Nalu Navarro-Alvarez, Jian Xu, Xia Li, Peng Li, Wenxue Wu
Chronic non-progressive pneumonia, a disease that has become a worldwide epidemic has caused considerable loss to sheep industry. Mycoplasma ovipneumoniae (M. ovipneumoniae) is the causative agent of interstitial pneumonia in sheep, goat and bighorn. We here have identified by immunogold and immunoblotting that elongation factor Tu (EF-Tu) and heat shock protein 70 (HSP 70) are membrane-associated proteins on M. ovipneumonaiea. We have evaluated the humoral and cellular immune responses in vivo by immunizing BALB/c mice with both purified recombinant proteins rEF-Tu and rHSP70...
2016: PloS One
John VanNice, Steven T Gregory, Divya Kamath, Michael O'Connor
Ribosomal protein L19 is an essential ribosomal protein and is a component of bridge B8, one of the protein-RNA bridges linking the large and small ribosomal subunits. Bridge B8 also contributes to the accuracy of translation by affecting GTPase activation by ribosome-bound aminoacyl tRNA-EF-Tu•GTP ternary complexes. Previous work has identified a limited number of accuracy-altering alterations in protein L19 of Salmonella enterica and Thermus thermophilus. Here, we have targeted the Escherichia coli rplS gene encoding L19 for mutagenesis and have screened for mutants with altered levels of miscoding...
September 2016: Biochimie
Ramachandra Dongre, Gert E Folkers, Claudio O Gualerzi, Rolf Boelens, Hans Wienk
Bacterial translation initiation factor IF2 complexed with GTP binds to the 30S ribosomal subunit, promotes ribosomal binding of fMet-tRNA, and favors the joining of the small and large ribosomal subunits yielding a 70S initiation complex ready to enter the translation elongation phase. Within the IF2 molecule subdomain G3, which is believed to play an important role in the IF2-30S interaction, is positioned between the GTP-binding G2 and the fMet-tRNA binding C-terminal subdomains. In this study the solution structure of subdomain G3 of Geobacillus stearothermophilus IF2 has been elucidated...
September 2016: Protein Science: a Publication of the Protein Society
Madlen Vetter, Talia L Karasov, Joy Bergelson
A first line of defense against pathogen attack for both plants and animals involves the detection of microbe-associated molecular patterns (MAMPs), followed by the induction of a complex immune response. Plants, like animals, encode several receptors that recognize different MAMPs. While these receptors are thought to function largely redundantly, the physiological responses to different MAMPs can differ in detail. Responses to MAMP exposure evolve quantitatively in natural populations of Arabidopsis thaliana, perhaps in response to environment specific differences in microbial threat...
June 2016: PLoS Genetics
Claudia Parada, Maite Orruño, Vladimir Kaberdin, Zaloa Bravo, Isabel Barcina, Inés Arana
Previous work demonstrated that physiological, morphological, and gene expression changes as well as the time-dependent entry into the viable but not culturable (VBNC) state are used by Vibrio species to survive and cope with diverse stress conditions including seasonal temperature downshifts and starvation. To learn more about the nature and specific contribution of membrane proteins to cell adaptation and survival, we analyzed variations in the protein composition of cell envelope and related them to morphological and physiological changes that were taking place during the long-term permanence of Vibrio harveyi in seawater microcosm at 4 °C...
October 2016: Microbial Ecology
Yu-Hung Yeh, Dario Panzeri, Yasuhiro Kadota, Yi-Chun Huang, Pin-Yao Huang, Chia-Nan Tao, Milena Roux, Hsiao-Chiao Chien, Tzu-Chuan Chin, Po-Wei Chu, Cyril Zipfel, Laurent Zimmerli
Plasma membrane-localized pattern recognition receptors (PRRs) such as FLAGELLIN SENSING2 (FLS2), EF-TU RECEPTOR (EFR), and CHITIN ELICITOR RECEPTOR KINASE1 (CERK1) recognize microbe-associated molecular patterns (MAMPs) to activate pattern-triggered immunity (PTI). A reverse genetics approach on genes responsive to the priming agent β-aminobutyric acid (BABA) revealed IMPAIRED OOMYCETE SUSCEPTIBILITY1 (IOS1) as a critical PTI player. Arabidopsis thaliana ios1 mutants were hypersusceptible to Pseudomonas syringae bacteria...
July 2016: Plant Cell
Urszula M McCaughan, Uma Jayachandran, Vadim Shchepachev, Zhuo Angel Chen, Juri Rappsilber, David Tollervey, Atlanta G Cook
Budding yeast Tsr1 is a ribosome biogenesis factor with sequence similarity to GTPases, which is essential for cytoplasmic steps in 40S subunit maturation. Here we present the crystal structure of Tsr1 at 3.6 Å. Tsr1 has a similar domain architecture to translational GTPases such as EF-Tu and the selenocysteine incorporation factor SelB. However, active site residues required for GTP binding and hydrolysis are absent, explaining the lack of enzymatic activity in previous analyses. Modelling of Tsr1 into cryo-electron microscopy maps of pre-40S particles shows that a highly acidic surface of Tsr1 is presented on the outside of pre-40S particles, potentially preventing premature binding to 60S subunits...
2016: Nature Communications
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