The Experts below are selected from a list of 14709 Experts worldwide ranked by ideXlab platform
Bryan Swingle - One of the best experts on this subject based on the ideXlab platform.
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regulons of three pseudomonas syringae pv tomato dc3000 iron starvation Sigma Factors
Applied and Environmental Microbiology, 2013Co-Authors: Eric Markel, Bronwyn G Butcher, Christopher R Myers, Paul Stodghill, Sam Cartinhour, Bryan SwingleAbstract:Pseudomonas syringae pv. tomato DC3000 contains genes for 15 Sigma Factors. The majority are members of the extracytoplasmic function class of Sigma Factors, including five that belong to the iron starvation subgroup. In this study, we identified the genes controlled by three iron starvation Sigma Factors. Their regulons are composed of a small number of genes likely to be involved in iron uptake.
Eric Markel - One of the best experts on this subject based on the ideXlab platform.
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regulons of three pseudomonas syringae pv tomato dc3000 iron starvation Sigma Factors
Applied and Environmental Microbiology, 2013Co-Authors: Eric Markel, Bronwyn G Butcher, Christopher R Myers, Paul Stodghill, Sam Cartinhour, Bryan SwingleAbstract:Pseudomonas syringae pv. tomato DC3000 contains genes for 15 Sigma Factors. The majority are members of the extracytoplasmic function class of Sigma Factors, including five that belong to the iron starvation subgroup. In this study, we identified the genes controlled by three iron starvation Sigma Factors. Their regulons are composed of a small number of genes likely to be involved in iron uptake.
Sam Cartinhour - One of the best experts on this subject based on the ideXlab platform.
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regulons of three pseudomonas syringae pv tomato dc3000 iron starvation Sigma Factors
Applied and Environmental Microbiology, 2013Co-Authors: Eric Markel, Bronwyn G Butcher, Christopher R Myers, Paul Stodghill, Sam Cartinhour, Bryan SwingleAbstract:Pseudomonas syringae pv. tomato DC3000 contains genes for 15 Sigma Factors. The majority are members of the extracytoplasmic function class of Sigma Factors, including five that belong to the iron starvation subgroup. In this study, we identified the genes controlled by three iron starvation Sigma Factors. Their regulons are composed of a small number of genes likely to be involved in iron uptake.
Arun K Chatterjee - One of the best experts on this subject based on the ideXlab platform.
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gaca the response regulator of a two component system acts as a master regulator in pseudomonas syringae pv tomato dc3000 by controlling regulatory rna transcriptional activators and alternate Sigma Factors
Molecular Plant-microbe Interactions, 2003Co-Authors: Asita Chatterjee, Hailian Yang, Alan Collmer, James R Alfano, Arun K ChatterjeeAbstract:Concerted investigations of Factors affecting host-pathogen interactions are now possible with the model plant Arabidopsis thaliana and its model pathogen Pseudomo-nas syringae pv. tomato DC3000, as their whole genome sequences have become available. As a prelude to analysis of the regulatory genes and their targets, we have focused on GacA, the response regulator of a two-component system. The DC3000 gene was cloned by testing for the reversal of phenotypes of an Erwinia GacA− mutant. A GacA− mutant of DC3000 constructed by marker exchange produces much-reduced levels of transcripts of three alternate Sigma Factors: HrpL, required for the production of effector proteins and their translocation via the type III secretion system; RpoS, required for stress responses and secondary metabolite production; and RpoN, required for an assortment of metabolic processes and expression of hrpL. GacA deficiency also reduces the expression of hrpR and hrpS, which specify enhancer-binding proteins of the NtrC family req...
Riccardo Manganelli - One of the best experts on this subject based on the ideXlab platform.
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the alternative Sigma Factors sige and sigb are involved in tolerance and persistence to antitubercular drugs
Antimicrobial Agents and Chemotherapy, 2017Co-Authors: Davide Pisu, Roberta Provvedi, Dulce Mata Espinosa, Jorge Barrios Payan, Francesca Boldrin, Giorgio Palu, Rogelio Hernandezpando, Riccardo ManganelliAbstract:: The emergence and spread of drug-resistant Mycobacterium tuberculosis strains possibly threaten our ability to treat this disease in the future. Even though two new antitubercular drugs have recently been introduced, there is still the need to design new molecules whose mechanisms of action could reduce the length of treatment. We show that two alternative Sigma Factors of M. tuberculosis (SigE and SigB) have a major role in determining the level of basal resistance to several drugs and the amount of persisters surviving long-duration drug treatment. We also demonstrate that ethambutol, a bacteriostatic drug, is highly bactericidal for M. tuberculosis mutants missing either SigE or SigB. We suggest that molecules able to interfere with the activity of SigE or SigB not only could reduce M. tuberculosis virulence in vivo but also could boost the effect of other drugs by increasing the sensitivity of the organism and reducing the number of persisters able to escape killing.
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14 Mycobacterial Sigma Factors and Surface Biology
The Mycobacterial Cell Envelope, 2008Co-Authors: Sahadevan Raman, Alessandro Cascioferro, Robert N. Husson, Riccardo ManganelliAbstract:Sigma Factors are interchangeable subunits of bacterial RNA polymerase that are required for promoter selectivity and transcription initiation. Sigma Factors regulate processes involved in cell surface biology in many bacterial species. The characterization of stress response systems used by bacteria to respond to surface stress is extremely important because it can contribute to a better understanding of both bacterial sensing and signaling through different cell compartments, and cell envelope physiology and biogenesis. Cell integrity stress, like other forms of stress, may lead to increased expression of chaperone/heat shock genes, and the activity of these heat shock proteins (Hsps) is likely to be essential for maintaining cell envelope homeostasis. Mpt53 is a secreted DsbE-like protein containing a thioredoxin-active site. This protein was recently characterized and hypothesized to be a functional homologue of DsbA, able to catalyze the formation of disulfide bonds in unfolded secreted proteins. Even though at the current state of knowledge it is difficult to assign many of the Sigma Factors specific functions, one can hypothesize that some of them, such as σF, σD and σE, regulate genes responsible for the maintenance of surface homeostasis following damage that can occur during stationary phase or following exposure to surface damaging host effector molecules. Others such as σL and σM appear to be involved in the regulation of the composition of the mycobacterial surface in response to still unknown stimuli and can play an important role in modulating Mycobacterium tuberculosis interactions with the host.
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the Sigma Factors of mycobacterium tuberculosis
Fems Microbiology Reviews, 2006Co-Authors: Sebastien Rodrigue, Roberta Provvedi, Pierreetienne Jacques, Luc Gaudreau, Riccardo ManganelliAbstract:: Mycobacterium tuberculosis is a remarkable pathogen capable of adapting and surviving in various harsh conditions. Correct gene expression regulation is essential for the success of this process. The reversible association of different Sigma Factors is a common mechanism for reprogramming bacterial RNA polymerase and modulating the transcription of numerous genes. Thirteen putative Sigma Factors are encoded in the M. tuberculosis genome, several being important for virulence. Here, we analyse the latest information available on mycobacterial Sigma Factors and discuss their roles in the physiology and virulence of M. tuberculosis.
