Resistance to hydrogen peroxide in Helicobacter pylori: Role of catalase (KatA) and Fur, and functional analysis of a novel gene product designated 'KatA-associated protein', KapA (HP0874)

Harris, A. G., Hinds, F. E., Beckhouse, A. G., Kolesnikow, T. and Hazell, S. L. (2002) Resistance to hydrogen peroxide in Helicobacter pylori: Role of catalase (KatA) and Fur, and functional analysis of a novel gene product designated 'KatA-associated protein', KapA (HP0874). Microbiology, 148 12: 3813-3825.

Author Harris, A. G.
Hinds, F. E.
Beckhouse, A. G.
Kolesnikow, T.
Hazell, S. L.
Title Resistance to hydrogen peroxide in Helicobacter pylori: Role of catalase (KatA) and Fur, and functional analysis of a novel gene product designated 'KatA-associated protein', KapA (HP0874)
Journal name Microbiology   Check publisher's open access policy
ISSN 1350-0872
1465-2080
Publication date 2002-12
Sub-type Article (original research)
Volume 148
Issue 12
Start page 3813
End page 3825
Total pages 13
Place of publication Reading, Berks, United Kingdom
Publisher Society for General Microbiology
Language eng
Abstract Helicobacter pylori infection elicits an aggressive inflammatory response that the bacterium is able to resist by virtue of its well-adapted antioxidant defence mechanisms. Catalase (KatA) appears to be a key enzyme in this resistance. Upstream of katA, a low-affinity ferric uptake regulator (Fur)-box has been identified. Downstream of katA, an ORF (HP0874) with no known function has also been identified. Non-polar isogenic mutants of katA, fur and HP0874 were constructed by allelic exchange. The impact of these mutations on the catalase activities and bacterial viability following exposure to hydrogen peroxide was studied. Concurrently, the effect of variation in the iron content of the media used to grow the cells was determined. The data showed that catalase-deficient isolates of H. pylori were hypersensitive to hydrogen peroxide, whereas wild-type cells could resist Ο 100 mM hydrogen peroxide. Fur-deficient mutants and cells grown on low-iron-containing medium showed a distinct reduction in catalase activity and increased sensitivity to hydrogen peroxide. The data suggest a direct or indirect effect of Fur and iron on the activity of catalase. HP0874-deficient mutants showed no reduction in catalase activity but showed an increased sensitivity to hydrogen peroxide. That is, the protein encoded by HP0874 appears to have a role in resistance to hydrogen peroxide not directly related to catalase activity. This is the first report of a functional relationship of the product of this ORF. There is evidence of protein-protein interaction between KatA and the product encoded by HP0874, and the name 'KatA-associated protein' (KapA) is proposed.
Keyword Influence of iron on catalase activity
Oxidative stress response
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: Australian Institute for Bioengineering and Nanotechnology Publications
 
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