A homologue to the Escherichia coli alkyl hydroperoxide reductase AhpC is induced by osmotic upshock in Staphylococcus aureus

Armstrong-Buisseret, Lindsay; Cole, M.; Stewart, Gordon S. A. B.

doi:10.1099/13500872-141-7-1655

Cited by 38 publications

(26 citation statements)

References 10 publications

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“…The induction of ahpC by peroxides was similar to that reported for other bacteria, except for Staphylococcus aureus, which has an oxidative stress-noninducible phenotype (2). The superoxide generators were potent inducers of ahpC.…”

Section: Resultssupporting

confidence: 59%

Characterization of transcription organization and analysis of unique expression patterns of an alkyl hydroperoxide reductase C gene (ahpC) and the peroxide regulator operon ahpF-oxyR-orfX from Xanthomonas campestris pv. phaseoli

et al. 1997

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We have analyzed the transcription organization of ahpC, ahpF, oxyR, and orfX from Xanthomonas campestris pv. phaseoli. ahpC was transcribed as a monocistronic 0.6-kb mRNA, while ahpF-oxyR-orfX were transcribed as a polycistronic approximately 3.0-kb-long mRNA. The novel transcription organization of these genes has not observed in other bacteria. Western analysis showed that oxidants (peroxides and superoxide anions), a thiol reagent (N-ethylmaleimide), and CdCl 2 caused large increases in the steady-state level of AhpC. Growth at alkaline pH also moderately induced AhpC accumulation. Thermal and osmotic stresses did not alter the levels of AhpC. Northern blotting results confirmed that oxidant-and CdCl 2 -induced AhpC accumulation was due to increased levels of ahpC transcripts. Analysis of oxyR expression revealed a unique pattern. Unlike other bacterial systems, peroxides and a superoxide generator induced accumulation of OxyR. Northern blotting results confirmed that these oxidants induced expression of oxyR operon. This novel regulatory pattern could be generally important. The transcription organization and patterns of chemicals and stress induction of ahpC and oxyR differed from those of other bacteria and are likely to be important for X. campestris pv. phaseoli survival during exposure to oxidants.

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Section: Resultssupporting

confidence: 59%

Characterization of transcription organization and analysis of unique expression patterns of an alkyl hydroperoxide reductase C gene (ahpC) and the peroxide regulator operon ahpF-oxyR-orfX from Xanthomonas campestris pv. phaseoli

et al. 1997

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“…The complete sequence of ahpF was inferred by combining the sequence of this HindIII fragment with that of a HindIII fragment sequenced by Zhang and Aronson (51) and was later verified when the complete sequence of this region of the chromosome was determined as part of the B. subtilis genome project (22) and by Antelmann et al (4). The B. subtilis AhpC and AhpF proteins are highly similar to related proteins from other organisms; both are over 50% identical to the corresponding homologs from Salmonella typhimurium (9,44) and have substantially higher identity to homologs from other gram-positive organisms, including Amphibacillus xylanus (27), Bacillus alcalophilus (48), and Staphylococcus aureus (5 (18), we inspected the gnt-ahp intergenic region for possible per box sequences (Fig. 2).…”

Section: Resultsmentioning

confidence: 99%

Mutation of the Bacillus subtilis alkyl hydroperoxide reductase (ahpCF) operon reveals compensatory interactions among hydrogen peroxide stress genes

1996

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In Bacillus subtilis, hydrogen peroxide induces the synthesis of catalase (KatA), alkyl hydroperoxide reductase (AhpCF), and a DNA-binding protein of the Dps family (MrgA). KatA, AhpCF, heme biosynthesis enzymes, and MrgA are also induced upon entry into stationary phase under conditions of iron and manganese limitation. In an effort to define the peroxide regulon repressor, PerR, we used mini-Tn10 mutagenesis to identify loci affecting the regulation of mrgA. From this screen, we isolated two mini-Tn10 insertions in ahpC, the gene encoding the small subunit of AhpCF, that increase the transcription of mrgA-lacZ even in ironsupplemented minimal medium. Indeed, these ahpC::Tn10 insertions lead to elevated expression from all peroxide regulon promoters, including those for mrgA, katA, hemAXCDBL, and ahpCF. As a result, the ahpC::Tn10 mutants display an increased resistance to H 2 O 2 . The ahpCF promoter region contains three sequences similar to the peroxide regulon consensus operator (per box). We demonstrate that the ability of ahpC::Tn10 mutations to derepress mrgA requires aerobic growth. In contrast, a second distinct trans-acting regulatory mutation bypasses this requirement for aerobic growth. Since the peroxide regulon is activated in the absence of AhpCF, which degrades alkyl hydroperoxides, we propose that organic hydroperoxides may be physiologically relevant inducers in vivo.

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“…The high degree of homology between these proteins suggested that they might have similar enzyme mechanisms. Cysteine residues involved in disulfide bridges, an ac- (2); DIR, C. diphtheriae (27); MYC, M. tuberculosis (8); and SUL, Sulfolobus sp. (U36479).…”

Section: Resultsmentioning

confidence: 99%

Isolation and analysis of the Xanthomonas alkyl hydroperoxide reductase gene and the peroxide sensor regulator genes ahpC and ahpF-oxyR-orfX

et al. 1997

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From Xanthomonas campestris pv. phaseoli, we have isolated by two independent methods genes involved in peroxide detoxification (ahpC and ahpF), a gene involved in peroxide sensing and transcription regulation (oxyR), and a gene of unknown function (orfX). Amino acid sequence analysis of AhpC, AhpF, and OxyR showed high identity with bacterial homologs. OrfX was a small cysteine-rich protein with no significant homology to known proteins. The genes ahpC, ahpF, oxyR, and orfX were arranged in a head-to-tail fashion. This unique arrangement was conserved in all of the Xanthomonas strains tested. The functionalities of both the ahpC and oxyR genes were demonstrated. In X. campestris pv. phaseoli, increased expression of ahpC alone conferred partial protection against growth retardation and killing by organic hydroperoxides but not by H 2 O 2 or superoxide generators. These genes are likely to have important physiological roles in protection against peroxide toxicity in Xanthomonas.

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A homologue to the Escherichia coli alkyl hydroperoxide reductase AhpC is induced by osmotic upshock in Staphylococcus aureus

Cited by 38 publications

References 10 publications

Characterization of transcription organization and analysis of unique expression patterns of an alkyl hydroperoxide reductase C gene (ahpC) and the peroxide regulator operon ahpF-oxyR-orfX from Xanthomonas campestris pv. phaseoli

Characterization of transcription organization and analysis of unique expression patterns of an alkyl hydroperoxide reductase C gene (ahpC) and the peroxide regulator operon ahpF-oxyR-orfX from Xanthomonas campestris pv. phaseoli

Mutation of the Bacillus subtilis alkyl hydroperoxide reductase (ahpCF) operon reveals compensatory interactions among hydrogen peroxide stress genes

Isolation and analysis of the Xanthomonas alkyl hydroperoxide reductase gene and the peroxide sensor regulator genes ahpC and ahpF-oxyR-orfX

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