The Experts below are selected from a list of 2061 Experts worldwide ranked by ideXlab platform
Gary M Dunny - One of the best experts on this subject based on the ideXlab platform.
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enterococcal sex Pheromones evolutionary pathways to complex two signal systems
Journal of Bacteriology, 2016Co-Authors: Gary M Dunny, Ronnie P A BerntssonAbstract:Gram-positive bacteria carry out intercellular communication using secreted Peptides. Important examples of this type of communication are the enterococcal sex Pheromone systems, in which the transfer of conjugative plasmids is controlled by intercellular signaling among populations of donors and recipients. This review focuses on the Pheromone response system of the conjugative plasmid pCF10. The Peptide Pheromones regulating pCF10 transfer act by modulating the ability of the PrgX transcription factor to repress the transcription of an operon encoding conjugation functions. Many Gram-positive bacteria regulate important processes, including the production of virulence factors, biofilm formation, sporulation, and genetic exchange using Peptide-mediated signaling systems. The key master regulators of these systems comprise the RRNPP (RggRap/NprR/PlcR/PrgX) family of intracellular Peptide receptors; these regulators show conserved structures. While many RRNPP systems include a core module of two linked genes encoding the regulatory protein and its cognate signaling Peptide, the enterococcal sex Pheromone plasmids have evolved to a complex system that also recognizes a second host-encoded signaling Peptide. Additional regulatory genes not found in most RRNPP systems also modulate signal production and signal import in the enterococcal Pheromone plasmids. This review summarizes several structural studies that cumulatively demonstrate that the ability of three pCF10 regulatory proteins to recognize the same 7-amino-acid Pheromone Peptide arose by convergent evolution of unrelated proteins from different families. We also focus on the selective pressures and structure/function constraints that have driven the evolution of pCF10 from a simple, single-Peptide system resembling current RRNPPs in other bacteria to the current complex inducible plasmid transfer system.
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cell associated Pheromone Peptide ccf10 production and Pheromone inhibition in enterococcus faecalis
Journal of Bacteriology, 2000Co-Authors: B A Buttaro, Michelle H Antiporta, Gary M DunnyAbstract:In Enterococcus faecalis, the Peptide cCF10 acts as a Pheromone, inducing transfer of the conjugative plasmid pCF10 from plasmid-containing donor cells to plasmid-free recipient cells. In these studies, it was found that a substantial amount of cCF10 associates with the envelope of the producing cell. Pheromone activity was detected in both wall and membrane fractions, with the highest activity associated with the wall. Experiments examining the effects of protease inhibitor treatments either prior to or following cell fractionation suggested the presence of a cell envelope-associated pro-cCF10 that can be processed to mature cCF10 by a maturase or protease. A pCF10-encoded membrane protein, PrgY, was shown to prevent self-induction of donor cells by reducing the level of Pheromone activity in the cell wall fraction.
B A Buttaro - One of the best experts on this subject based on the ideXlab platform.
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cell associated Pheromone Peptide ccf10 production and Pheromone inhibition in enterococcus faecalis
Journal of Bacteriology, 2000Co-Authors: B A Buttaro, Michelle H Antiporta, Gary M DunnyAbstract:In Enterococcus faecalis, the Peptide cCF10 acts as a Pheromone, inducing transfer of the conjugative plasmid pCF10 from plasmid-containing donor cells to plasmid-free recipient cells. In these studies, it was found that a substantial amount of cCF10 associates with the envelope of the producing cell. Pheromone activity was detected in both wall and membrane fractions, with the highest activity associated with the wall. Experiments examining the effects of protease inhibitor treatments either prior to or following cell fractionation suggested the presence of a cell envelope-associated pro-cCF10 that can be processed to mature cCF10 by a maturase or protease. A pCF10-encoded membrane protein, PrgY, was shown to prevent self-induction of donor cells by reducing the level of Pheromone activity in the cell wall fraction.
Michelle H Antiporta - One of the best experts on this subject based on the ideXlab platform.
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cell associated Pheromone Peptide ccf10 production and Pheromone inhibition in enterococcus faecalis
Journal of Bacteriology, 2000Co-Authors: B A Buttaro, Michelle H Antiporta, Gary M DunnyAbstract:In Enterococcus faecalis, the Peptide cCF10 acts as a Pheromone, inducing transfer of the conjugative plasmid pCF10 from plasmid-containing donor cells to plasmid-free recipient cells. In these studies, it was found that a substantial amount of cCF10 associates with the envelope of the producing cell. Pheromone activity was detected in both wall and membrane fractions, with the highest activity associated with the wall. Experiments examining the effects of protease inhibitor treatments either prior to or following cell fractionation suggested the presence of a cell envelope-associated pro-cCF10 that can be processed to mature cCF10 by a maturase or protease. A pCF10-encoded membrane protein, PrgY, was shown to prevent self-induction of donor cells by reducing the level of Pheromone activity in the cell wall fraction.
Jay Kant Yadav - One of the best experts on this subject based on the ideXlab platform.
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Pheromone Peptide cob1 from native enterococcus faecalis forms amyloid like structures a new paradigm for Peptide Pheromones
Journal of Peptide Science, 2019Co-Authors: Shalini Gour, Vijay Kumar, Monika Rana, Jay Kant YadavAbstract:Pheromone Peptides are an important component of bacterial quorum-sensing system. The Pheromone Peptide cOB1 (VAVLVLGA) of native commensal Enterococcus faecalis has also been identified as an antimicrobial Peptide (AMP) and reported to kill the prototype clinical isolate strain of E. faecalis V583. In this study, the Pheromone Peptide cOB1 has shown to form amyloid-like structures, a characteristic which is never reported for a Pheromone Peptide so far. With in silico analysis, the Peptide was predicted to be highly amyloidogenic. Further, under experimental conditions, cOB1 formed aggregates displaying characteristics of amyloid structures such as bathochromic shift in Congo red absorbance, enhancement in thioflavin T fluorescence, and fibrillar morphology under transmission electron microscopy. This novel property of Pheromone Peptide cOB1 may have some direct effects on the binding of the Pheromone to the receptor cells and subsequent conjugative transfer, making this observation more important for the therapeutics, dealing with the generation of virulent and multidrug-resistant pathogenic strains.
Friedrich Gotz - One of the best experts on this subject based on the ideXlab platform.
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structure of the Pheromone Peptide of the staphylococcus epidermidis agr system
FEBS Letters, 1998Co-Authors: Michael Otto, Roderich Susmuth, Gunther Jung, Friedrich GotzAbstract:The agr quorum-sensing system is responsible for the regulation of several virulence factors in staphylococci, with an extracellular Pheromone Peptide as signalling molecule. By monitoring the biological activity of synthetic Peptides, it could be demonstrated that the Pheromone of the agr system in Staphylococcus epidermidis is an octaPeptide containing a thiolester linkage between the central cysteine and the C-terminal carboxyl group. The Peptide was active at nanomolar concentrations. The N-terminus of the Peptide Pheromone, which is encoded as part of a protein precursor, proved to be crucial for biological activity.