scholarly journals Regulation of Expression of Oxacillin-Inducible Methionine Sulfoxide Reductases inStaphylococcus aureus

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Kyle R. Baum ◽  
Zulfiqar Ahmad ◽  
Vineet K. Singh
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Methionine Sulfoxide ◽  
Galactosidase Activity ◽  
Growth Phases ◽  
Wild Type ◽  
Regulation Of Expression ◽  
Methionine Sulfoxide Reductases ◽  
Reporter Strains ◽  
Dna Fragment

Cell wall-active antibiotics cause induction of a locus that leads to elevated synthesis of two methionine sulfoxide reductases (MsrA1 and MsrB) inStaphylococcus aureus. To understand the regulation of this locus, reporter strains were constructed by integrating a DNA fragment consisting of themsrA1/msrBpromoter in front of a promoterlesslacZgene in the chromosome of wild-type and MsrA1-, MsrB-, MsrA1/MsrB-, and SigB-deficient methicillin-sensitiveS. aureusstrain SH1000 and methicillin-resistantS. aureusstrain COL. These reporter strains were cultured in TSB and the cellular levels ofβ-galactosidase activity in these cultures were assayed during different growth phases.β-galactosidase activity assays demonstrated that the lack of MsrA1, MsrB, and SigB upregulated themsrA1/msrBpromoter inS. aureusstrain SH1000. InS. aureusstrain COL, the highest level ofβ-galactosidase activity was observed under the conditions when both MsrA1 and MsrB proteins were absent. The data suggest that themsrA1/msrBlocus, in part, is negatively regulated by MsrA1, MsrB, and SigB inS. aureus.

scholarly journals Expression of Four Methionine Sulfoxide Reductases inStaphylococcus aureus

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Kuldeep Singh ◽  
Vineet K. Singh
Keyword(s):  
Staphylococcus Aureus ◽  
Stationary Phase ◽  
Expression Pattern ◽  
Growth Phase ◽  
Methionine Sulfoxide ◽  
Phase Growth ◽  
Methionine Sulfoxide Reductases ◽  
Reporter Strains

Staphylococcus aureuspossesses three MsrA enzymes (MsrA1, MsrA2, MsrA3) that reduce the S-epimer of methionine sulfoxide (MetO) and an MsrB enzyme that reduces R-MetO. The fourmsrgenes are expressed from three different promoters. ThemsrA1/msrBgenes are coexpressed. To determine the expression pattern ofmsrgenes, three independent reporter strains were constructed wheremsrpromoter was cloned in front of a promoterlesslacZand the resulting construct was integrated in the chromosome. Using these strains, it was determined that themsrA1/Bexpression is significantly higher inS. aureuscompared tomsrA2ormsrA3. Expression ofmsrA1/Bwas highest during stationary phase growth, but the expression ofmsrA2andmsrA3was highest during the early to midexponential growth phase. Expression ofmsrA1/Bwas induced by oxacillin and the expression ofmsrA3was upregulated by salt. Expression ofmsrA2remained unchanged under all tested conditions.

scholarly journals The Role of Methionine Sulfoxide Reductases in Oxidative Stress Tolerance and Virulence of Staphylococcus aureus and Other Bacteria

Antioxidants ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 128 ◽  
Author(s):  
Vineet Singh ◽  
Kuldeep Singh ◽  
Kyle Baum
Keyword(s):  
Oxidative Stress ◽  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Regulatory Network ◽  
Current Knowledge ◽  
Methionine Sulfoxide ◽  
Oxidative Stress Tolerance ◽  
Methionine Sulfoxide Reductases ◽  
Encoding Genes

Methionine sulfoxide reductases (MSRA1 and MSRB) are proteins overproduced in Staphylococcus aureus during exposure with cell wall-active antibiotics. Later studies identified the presence of two additional MSRA proteins (MSRA2 and MSRA3) in S. aureus. These MSR proteins have been characterized in many other bacteria as well. This review provides the current knowledge about the conditions and regulatory network that mimic the expression of these MSR encoding genes and their role in defense from oxidative stress and virulence.

scholarly journals Methionine Sulfoxide Reductases Protect against Oxidative Stress in Staphylococcus aureus Encountering Exogenous Oxidants and Human Neutrophils

2013 ◽  
Vol 6 (3) ◽  
pp. 353-364 ◽  
Author(s):  
Yun Yun Pang ◽  
Jamie Schwartz ◽  
Sarah Bloomberg ◽  
Jeffrey M. Boyd ◽  
Alexander R. Horswill ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Staphylococcus Aureus ◽  
Methionine Sulfoxide ◽  
Human Neutrophils ◽  
Methionine Sulfoxide Reductases

scholarly journals Alterations in the DNA topoisomerase IV grlA gene responsible for quinolone resistance in Staphylococcus aureus.

1996 ◽  
Vol 40 (5) ◽  
pp. 1157-1163 ◽  
Author(s):  
J Yamagishi ◽  
T Kojima ◽  
Y Oyamada ◽  
K Fujimoto ◽  
H Hattori ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Gene Dosage ◽  
Dna Gyrase ◽  
Quinolone Resistance ◽  
Wild Type Allele ◽  
Wild Type ◽  
Topoisomerase Iv ◽  
Dna Topoisomerase ◽  
Transformation Experiment ◽  
Dna Fragment

A 4.2-kb DNA fragment conferring quinolone resistance was cloned from a quinolone-resistant clinical isolate of Staphylococcus aureus and was shown to possess a part of the grlB gene and a mutated grlA gene. S-80-->F and E-84-->K mutations in the grlA gene product were responsible for the quinolone resistance. The mutated grlA genes responsible for quinolone resistance were dominant over the wild-type allele, irrespective of gene dosage in a transformation experiment with the grlA gene alone. However, dominance by mutated grlA genes depended on gene dosage when bacteria were transformed with the grlA and grlB genes in combination. Quinolone-resistant gyrA mutants were easily isolated from a strain, S. aureus RN4220, carrying a plasmid with the mutated grlA gene, though this was not the case for other S. aureus strains lacking the plasmid. The elimination of this plasmid from such quinolone-resistant gyrA mutants resulted in marked increases in quinolone susceptibility. These results suggest that both DNA gyrase and DNA topoisomerase IV may be targets of quinolones and that the quinolone susceptibility of organisms may be determined by which of these enzymes is most quinolone sensitive.

scholarly journals Control of Glucose- and NaCl-Induced Biofilm Formation by rbf in Staphylococcus aureus

2004 ◽  
Vol 186 (3) ◽  
pp. 722-729 ◽  
Author(s):  
Yong Lim ◽  
Malabendu Jana ◽  
Thanh T. Luong ◽  
Chia Y. Lee
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Wild Type ◽  
High Concentration ◽  
Phenotypic Analysis ◽  
Consensus Region ◽  
Dna Fragment ◽  
Aggregation Step

ABSTRACT Both Staphylococcus aureus and S. epidermidis are capable of forming biofilm on biomaterials. We used Tn917 mutagenesis to identify a gene, rbf, affecting biofilm formation in S. aureus NCTC8325-4. Sequencing revealed that Rbf contained a consensus region signature of the AraC/XylS family of regulators, suggesting that Rbf is a transcriptional regulator. Insertional duplication inactivation of the rbf gene confirmed that the gene was involved in biofilm formation on polystyrene and glass. Phenotypic analysis of the wild type and the mutant suggested that the rbf gene mediates the biofilm formation of S. aureus at the multicellular aggregation stage rather than at initial attachment. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis demonstrated that the mutation resulted in the loss of an ∼190-kDa protein. Biofilm production by the mutant could be restored by complementation with a 2.5-kb DNA fragment containing the rbf gene. The rbf-specific mutation affected the induction of biofilm formation by glucose and a high concentration of NaCl but not by ethanol. The mutation did not affect the transcription of the ica genes previously shown to be required for biofilm formation. Taken together, our results suggest that the rbf gene is involved in the regulation of the multicellular aggregation step of S. aureus biofilm formation in response to glucose and salt and that this regulation may be mediated through the 190-kDa protein.

scholarly journals ThemsaABCROperon Regulates Resistance in Vancomycin-Intermediate Staphylococcus aureus Strains

2014 ◽  
Vol 58 (11) ◽  
pp. 6685-6695 ◽  
Author(s):  
Dhritiman Samanta ◽  
Mohamed O. Elasri
Keyword(s):  
Public Health ◽  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Binding Capacity ◽  
Difficult Problem ◽  
Cell Wall Synthesis ◽  
Wild Type ◽  
Content Type ◽  
Type Strains

ABSTRACTVancomycin-intermediateStaphylococcus aureus(VISA) strains present an increasingly difficult problem in terms of public health. However, the molecular mechanism for this resistance is not yet understood. In this study, we define the role of themsaABCRoperon in vancomycin resistance in three clinical VISA strains, i.e., Mu50, HIP6297, and LIM2. Deletion of themsaABCRoperon resulted in significant decreases in the vancomycin MIC (from 6.25 to 1.56 μg/ml) and significant reductions of cell wall thickness in strains Mu50 and HIP6297. Growth of the mutants in medium containing vancomycin at concentrations greater than 2 μg/ml resulted in decreases in the growth rate, compared with the wild-type strains. Mutation of themsaABCRoperon also reduced the binding capacity for vancomycin. We conclude that themsaABCRoperon contributes to resistance to vancomycin and cell wall synthesis inS. aureus.

scholarly journals Epigallocatechin Gallate Induces Upregulation of the Two-Component VraSR System by Evoking a Cell Wall Stress Response in Staphylococcus aureus

2012 ◽  
Vol 78 (22) ◽  
pp. 7954-7959 ◽  
Author(s):  
Oren Levinger ◽  
Tamar Bikels-Goshen ◽  
Elad Landau ◽  
Merav Fichman ◽  
Roni Shapira
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Epigallocatechin Gallate ◽  
Wall Stress ◽  
Null Mutant ◽  
Wild Type ◽  
Content Type ◽  
Cell Wall Stress ◽  
Two Component ◽  
A Cell

ABSTRACTWe previously found that a short exposure ofStaphylococcus aureusto subinhibitory (SI) doses of epigallocatechin gallate (EGCG) results in increased cell wall thickness, adaptation, and enhanced tolerance to cell-wall-targeted antibiotics. In this study, the response to EGCG ofsigBandvraSRtranscription factor mutants was characterized. We show that in contrast to the results observed for wild-type (WT) strains, anS. aureus315vraSRnull mutant exposed to SI doses of EGCG did not exhibit increased tolerance to EGCG and oxacillin. A diminished increase in tolerance to ampicillin (from 16-fold to 4-fold) and no change in the magnitude of resistance to vancomycin were observed. Preexposure to EGCG enhanced the tolerance of wild-type andsigBnull mutant cells to lysostaphin, but this enhancement was much weaker in thevraSRnull mutant. Marked upregulation (about 60-fold) ofvraRand upregulation of the peptidoglycan biosynthesis-associated genesmurA,murF, andpbp2(2-, 5-, and 6-fold, respectively) in response to SI doses of EGCG were determined by quantitative reverse transcription-PCR (qRT-PCR). EGCG also induced the promoter ofsas016(encoding a cell wall stress protein of unknown function which is not induced invraSRnull mutants) in a concentration-dependent manner, showing kinetics comparable to those of cell-wall-targeting antibiotics. Taken together, our results suggest that the two-component VraSR system is involved in modulating the cell response to SI doses of EGCG.

scholarly journals The Thioredoxin Domain of Neisseria gonorrhoeae PilB Can Use Electrons from DsbD to Reduce Downstream Methionine Sulfoxide Reductases

2006 ◽  
Vol 281 (43) ◽  
pp. 32668-32675 ◽  
Author(s):  
Nathan Brot ◽  
Jean-François Collet ◽  
Lynnette C. Johnson ◽  
Thomas J. Jönsson ◽  
Herbert Weissbach ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Methionine Sulfoxide ◽  
Methionine Sulfoxide Reductase ◽  
Wild Type ◽  
Methionine Sulfoxide Reductase A ◽  
Surface Loop ◽  
Methionine Sulfoxide Reductases ◽  
Domain Interactions ◽  
Frame Work

The PilB protein from Neisseria gonorrhoeae is located in the periplasm and made up of three domains. The N-terminal, thioredoxin-like domain (NT domain) is fused to tandem methionine sulfoxide reductase A and B domains (MsrA/B). We show that the α domain of Escherichia coli DsbD is able to reduce the oxidized NT domain, which suggests that DsbD in Neisseria can transfer electrons from the cytoplasmic thioredoxin to the periplasm for the reduction of the MsrA/B domains. An analysis of the available complete genomes provides further evidence for this proposition in other bacteria where DsbD/CcdA, Trx, MsrA, and MsrB gene homologs are all located in a gene cluster with a common transcriptional direction. An examination of wild-type PilB and a panel of Cys to Ser mutants of the full-length protein and the individually expressed domains have also shown that the NT domain more efficiently reduces the MsrA/B domains when in the polyprotein context. Within this frame-work there does not appear to be a preference for the NT domain to reduce the proximal MsrA domain over MsrB domain. Finally, we report the 1.6Å crystal structure of the NT domain. This structure confirms the presence of a surface loop that makes it different from other membrane-tethered, Trx-like molecules, including TlpA, CcmG, and ResA. Subtle differences are observed in this loop when compared with the Neisseria meningitidis NT domain structure. The data taken together supports the formation of specific NT domain interactions with the MsrA/B domains and its in vivo recycling partner, DsbD.

Lack of a functional methionine sulfoxide reductase (MsrB) increases oxacillin and H2O2 stress resistance and enhances pigmentation in Staphylococcus aureus

2014 ◽  
Vol 60 (9) ◽  
pp. 625-628 ◽  
Author(s):  
Vineet K. Singh
Keyword(s):  
Staphylococcus Aureus ◽  
Stress Resistance ◽  
Methionine Sulfoxide ◽  
Methionine Sulfoxide Reductase ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Wild Type ◽  
Genes Encoding ◽  
Increased Sensitivity ◽  
Mutant Cells

Staphylococcus aureus produces 3 MsrA enzymes (MsrA1, MsrA2, and MsrA3) and 1 MsrB enzyme. The genes encoding MsrA1 and MsrB are the first and second genes of a 4-gene operon in S. aureus. In a previous study, MsrA1-deficient S. aureus cells showed increased sensitivity to oxidative stress conditions in spite of a higher production of MsrB. In this study, an msrB mutant of S. aureus was created by site-directed mutagenesis that left the first gene of this locus, msrA1, intact. Studies with this mutant suggest that a deletion of MsrB increases resistance of S. aureus to H2O2 and oxacillin and that the mutant cells produce a higher level of carotenoids relative to wild-type S. aureus cells.

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