Characterization of Brucella suis clpB and clpAB mutants and participation of the genes in stress responses.
Pathogens often encounter stressful conditions inside their hosts. In the attempt to characterize the stress response in Brucella suis, a gene highly homologous to Escherichia coli clpB was isolated from Brucella suis, and the deduced amino acid sequence showed features typical of the ClpB ATPase family of stress response proteins. Under high-temperature stress conditions, ClpB of B. suis was induced, and an isogenic B. suis clpB mutant showed increased sensitivity to high temperature, but also to ethanol stress and acid pH. The effects were reversible by complementation. Simultaneous inactivation of clpA and clpB resulted in a mutant that was sensitive to oxidative stress. In B. suis expressing gfp, ClpA but not ClpB participated in degradation of the green fluorescent protein at 42 degrees C. We concluded that ClpB was responsible for tolerance to several stresses and that the lethality caused by harsh environmental conditions may have similar molecular origins.
Institut National de la Santé et de la Recherche Médicale U-431, Université Montpellier II, F-34095 Montpellier, France.
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E
Ekaza
J
J
Teyssier
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Ouahrani-Bettache
J P
JP
Liautard
S
S
Köhler
D000251:Adenosine Triphosphatases / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002002:Brucella / Q000235:genetics* / Q000502:physiology*; D049071:Endopeptidase Clp; D029968:Escherichia coli Proteins; D000431:Ethanol / Q000494:pharmacology; D005798:Genes, Bacterial; D049452:Green Fluorescent Proteins; D006360:Heat-Shock Proteins / Q000235:genetics* / Q000378:metabolism; D018869:Heat-Shock Response; D006863:Hydrogen-Ion Concentration; D008164:Luminescent Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D018384:Oxidative Stress; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism; D012697:Serine Endopeptidases / Q000235:genetics* / Q000378:metabolism; D013696:Temperature
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; D008164:Luminescent Proteins; D015800:Protozoan Proteins; D049452:Green Fluorescent Proteins; D000431:Ethanol; D012697:Serine Endopeptidases; C483568:ClpA protease, E coli; D049071:Endopeptidase Clp; D000251:Adenosine Triphosphatases; C424712:ClpB protein, Brucella suis; C095049:ClpB protein, Leishmania