Journal article
Characterization of Virulence Factor Regulation by SrrAB, a Two-Component System in Staphylococcus aureus
Journal of bacteriology, Vol.186(8), pp.2430-2438
04/2004
DOI: 10.1128/JB.186.8.2430-2438.2004
PMCID: PMC412142
PMID: 15060046
Abstract
Workers in our laboratory have previously identified the staphylococcal respiratory response AB (SrrAB), a
Staphylococcus aureus
two-component system that acts in the global regulation of virulence factors. This system down-regulates production of
agr
RNAIII, protein A, and toxic shock syndrome toxin 1 (TSST-1), particularly under low-oxygen conditions. In this study we investigated the localization and membrane orientation of SrrA and SrrB, transcription of the
srrAB
operon, the DNA-binding properties of SrrA, and the effect of SrrAB expression on
S. aureus
virulence. We found that SrrA is localized to the
S. aureus
cytoplasm, while SrrB is localized to the membrane and is properly oriented to function as a histidine kinase.
srrAB
has one transcriptional start site which results in either an
srrA
transcript or a full-length
srrAB
transcript;
srrB
must be cotranscribed with
srrA
. Gel shift assays of the
agr
P2,
agr
P3, protein A (
spa
), TSST-1 (
tst
), and
srr
promoters revealed SrrA binding at each of these promoters. Analysis of SrrAB-overexpressing strains by using the rabbit model of bacterial endocarditis demonstrated that overexpression of SrrAB decreased the virulence of the organisms compared to the virulence of isogenic strains that do not overexpress SrrAB. We concluded that SrrAB is properly localized and oriented to function as a two-component system. Overexpression of SrrAB, which represses
agr
RNAIII, TSST-1, and protein A in vitro, decreases virulence in the rabbit endocarditis model. Repression of these virulence factors is likely due to a direct interaction between SrrA and the
agr
,
tst
, and
spa
promoters.
Details
- Title: Subtitle
- Characterization of Virulence Factor Regulation by SrrAB, a Two-Component System in Staphylococcus aureus
- Creators
- Alexa A Pragman - Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455Jeremy M Yarwood - Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455Timothy J Tripp - Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455Patrick M Schlievert - Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455
- Resource Type
- Journal article
- Publication Details
- Journal of bacteriology, Vol.186(8), pp.2430-2438
- DOI
- 10.1128/JB.186.8.2430-2438.2004
- PMID
- 15060046
- PMCID
- PMC412142
- NLM abbreviation
- J Bacteriol
- ISSN
- 0021-9193
- eISSN
- 1098-5530
- Publisher
- American Society for Microbiology
- Language
- English
- Date published
- 04/2004
- Academic Unit
- Microbiology and Immunology; Internal Medicine
- Record Identifier
- 9984002394802771
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