Localisation of<i>Helicobacter pylori</i>catalase in both the periplasm and cytoplasm, and its dependence on the twin-arginine target protein, KapA, for activity

Harris, Andrew G.; Hazell, Stuart L.

doi:10.1016/s0378-1097(03)00850-4

Cited by 44 publications

(51 citation statements)

References 38 publications

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“…The conservation of Cj1386 and its genetic organization among diverse microorganisms underscores its importance in bacterial physiology. Studies involving genes that affect catalase activity have been carried out in other bacterial species such as Helicobacter pylori (20) and Pseudomonas aeruginosa (25); however, our findings demonstrate a novel role for Cj1386 compared to these previous studies.…”

Section: Discussioncontrasting

confidence: 66%

“…Altogether, these results indicate that that Cj1386 is important in promoting proper catalase activity in C. jejuni and that C. jejuni catalase is located in both the periplasmic and cytoplasmic fractions. Catalase enzymes have also been shown to be present within both the cytoplasmic and periplasmic spaces of other bacterial species, including KatA in Helicobacter pylori (20), Vibrio rumoiensis (51), and Pseudomonas aeruginosa (14); CatF in Pseudomonas syringae (29); and a catalase/peroxidase in Caulobacter crescentus (38).…”

Section: Resultsmentioning

confidence: 99%

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Cj1386 Is an Ankyrin-Containing Protein Involved in Heme Trafficking to Catalase in Campylobacter jejuni

2012

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Campylobacter jejuni, a microaerophilic bacterium, is the most frequent cause of human bacterial gastroenteritis. C. jejuni is exposed to harmful reactive oxygen species (ROS) produced during its own normal metabolic processes and during infection from the host immune system and from host intestinal microbiota. These ROS will damage DNA and proteins and cause peroxidation of lipids. Consequently, identifying ROS defense mechanisms is important for understanding how Campylobacter survives this environmental stress during infection. Construction of a ⌬Cj1386 isogenic deletion mutant and phenotypic assays led to its discovery as a novel oxidative stress defense gene. The ⌬Cj1386 mutant has an increased sensitivity toward hydrogen peroxide. The Cj1386 gene is located directly downstream from katA (catalase) in the C. jejuni genome. A ⌬katA⌬ Cj1386 double deletion mutant was constructed and exhibited a sensitivity to hydrogen peroxide similar to that seen in the ⌬Cj1386 and ⌬katA single deletion mutants. This observation suggests that Cj1386 may be involved in the same detoxification pathway as catalase. Despite identical KatA abundances, catalase activity assays showed that the ⌬Cj1386 mutant had a reduced catalase activity relative to that of wild-type C. jejuni. Heme quantification of KatA protein from the ⌬Cj1386 mutant revealed a significant decrease in heme concentration. This indicates an important role for Cj1386 in heme trafficking to KatA within C. jejuni. Interestingly, the ⌬Cj1386 mutant had a reduced ability to colonize the ceca of chicks and was outcompeted by the wild-type strain for colonization of the gastrointestinal tract of neonate piglets. These results indicate an important role for Cj1386 in Campylobacter colonization and pathogenesis.

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Section: Discussioncontrasting

confidence: 66%

Section: Resultsmentioning

confidence: 99%

Cj1386 Is an Ankyrin-Containing Protein Involved in Heme Trafficking to Catalase in Campylobacter jejuni

2012

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“…periplasm) where the lipid hydroperoxides could be much more concentrated. In this regard, it is of note that approximately half of the total catalase is located in the periplasm of H. pylori cells (43).…”

Section: Fig 2 Catalase Activities and The Epr Signals In Various Hmentioning

confidence: 99%

Role of a Bacterial Organic Hydroperoxide Detoxification System in Preventing Catalase Inactivation

Wang¹,

Conover

Benoit³

et al. 2004

Journal of Biological Chemistry

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In the gastric pathogen Helicobacter pylori, catalase (KatA) and alkyl hydroperoxide reductase (AhpC) are two highly abundant enzymes that are crucial for oxidative stress resistance and survival of the bacterium in the host. Here we report a connection unidentified previously between the two stress resistance enzymes. We observed that the catalase in ahpC mutant cells in comparison with the parent strain is inactivated partially (approximately 50%). The decrease of catalase activity is well correlated with the perturbation of the heme environment in catalase, as detected by electron paramagnetic resonance spectroscopy. To understand the reason for this catalase inactivation, we examined the inhibitory effects of hydroperoxides on H. pylori catalase (either present in cell extracts or added to the purified enzyme) by monitoring the enzyme activity and the EPR signal of catalase. H. pylori catalase is highly resistant to its own substrate, without the loss of enzyme activity by treatment with a molar ratio of 1:3000 H 2 O 2 . However, it is inactivated by lower concentrations of organic hydroperoxides (the substrate of AhpC). Treatment with a molar ratio of 1:400 t-butyl hydroperoxide resulted in an inactivation of catalase by approximately 50%. UV-visible absorption spectra indicated that the catalase inactivation by organic hydroperoxides is caused by the formation of a catalytically incompetent compound II species. To further support the idea that organic hydroperoxides, which accumulate in the ahpC mutant cells, are responsible for the inactivation of catalase, we compared the level of lipid peroxidation found in ahpC mutant cells with that found in wild type cells. The results showed that the total amount of extractable lipid hydroperoxides in the ahpC mutant cells is approximately three times that in the wild type cells. Our findings reveal a novel role of the organic hydroperoxide detoxification system in preventing catalase inactivation.

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“…The function of KatA appears to be associated with a downstream gene, kapA, which encodes the KatAassociated protein (KapA) (46). There is evidence that KapA may be involved in translocation of the catalase enzyme into the periplasmic space, as H. pylori KapA mutants had reduced catalase activity in the periplasmic fraction (45). In addition to its occurrence in the cytoplasm and periplasmic space, catalase has been characterized as a secreted protein (4,89) and an outer membrane protein (4,7,86), supporting a role for the enzyme in defense against exogenous ROS.…”

mentioning

confidence: 99%

Helicobacter pyloridefense against oxidative attack

Stent

Every

Sutton

2012

American Journal of Physiology-Gastrointestinal and Liver Physi

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Localisation ofHelicobacter pyloricatalase in both the periplasm and cytoplasm, and its dependence on the twin-arginine target protein, KapA, for activity

Cited by 44 publications

References 38 publications

Cj1386 Is an Ankyrin-Containing Protein Involved in Heme Trafficking to Catalase in Campylobacter jejuni

Cj1386 Is an Ankyrin-Containing Protein Involved in Heme Trafficking to Catalase in Campylobacter jejuni

Role of a Bacterial Organic Hydroperoxide Detoxification System in Preventing Catalase Inactivation

Helicobacter pyloridefense against oxidative attack

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