NapA protects Helicobacter pylori from oxidative stress damage, and its production is influenced by the ferric uptake regulator.
The Helicobacter pylori protein NapA has been identified as a homologue of the Escherichia coli protein Dps. It is shown in this study that, like Dps, NapA is produced maximally in stationary phase cells and contributes to the ability of H. pylori to survive under oxidative stress conditions. Moreover, NapA co-localizes with the nuclear material, suggesting that it can interact with DNA in vivo. Furthermore, it is demonstrated that repression of NapA production by iron starvation was not so pronounced in a H. pylori fur mutant, suggesting that the ferric uptake regulator (Fur) is involved in napA regulation, and a potential fur box by which this control could be mediated is identified. This finding is consistent with the regulation of iron-binding proteins by Fur and also the modulation of Fur during oxidative stress, thus allowing NapA levels to be increased in the environmental conditions under which its ability to protect DNA from attack by toxic free radicals is most beneficial to the cell.
Institute of Infections and Immunity, Queen's Medical Centre, C-floor West Block, Nottingham NG7 2UH, UK 2Division of Gastroenterology, University Hospital, Nottingham NG7 2UH, UK 3School of Pharmaceutical Sciences, Nottingham University, Nottingham NG7 2RD, UK#dReceived 10 September 2002 Accepted 21 January 2003.
Clare
C
Cooksley
Institute of Infections and Immunity, Queen's Medical Centre, C-floor West Block, Nottingham NG7 2UH, UK 2Division of Gastroenterology, University Hospital, Nottingham NG7 2UH, UK 3School of Pharmaceutical Sciences, Nottingham University, Nottingham NG7 2RD, UK#dReceived 10 September 2002 Accepted 21 January 2003.
Peter J
PJ
Jenks
Institute of Infections and Immunity, Queen's Medical Centre, C-floor West Block, Nottingham NG7 2UH, UK 2Division of Gastroenterology, University Hospital, Nottingham NG7 2UH, UK 3School of Pharmaceutical Sciences, Nottingham University, Nottingham NG7 2RD, UK#dReceived 10 September 2002 Accepted 21 January 2003.
Andrew
A
Green
Institute of Infections and Immunity, Queen's Medical Centre, C-floor West Block, Nottingham NG7 2UH, UK 2Division of Gastroenterology, University Hospital, Nottingham NG7 2UH, UK 3School of Pharmaceutical Sciences, Nottingham University, Nottingham NG7 2RD, UK#dReceived 10 September 2002 Accepted 21 January 2003.
Alan
A
Cockayne
Institute of Infections and Immunity, Queen's Medical Centre, C-floor West Block, Nottingham NG7 2UH, UK 2Division of Gastroenterology, University Hospital, Nottingham NG7 2UH, UK 3School of Pharmaceutical Sciences, Nottingham University, Nottingham NG7 2RD, UK#dReceived 10 September 2002 Accepted 21 January 2003.
Robert P H
RPH
Logan
Institute of Infections and Immunity, Queen's Medical Centre, C-floor West Block, Nottingham NG7 2UH, UK 2Division of Gastroenterology, University Hospital, Nottingham NG7 2UH, UK 3School of Pharmaceutical Sciences, Nottingham University, Nottingham NG7 2RD, UK#dReceived 10 September 2002 Accepted 21 January 2003.
Kim R
KR
Hardie
D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D004269:DNA, Bacterial / Q000737:chemistry / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D016480:Helicobacter pylori / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D007501:Iron / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008858:Microscopy, Phase-Contrast; D008969:Molecular Sequence Data; D009154:Mutation; D018384:Oxidative Stress; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000502:physiology*; D016415:Sequence Alignment
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D011994:Recombinant Proteins; D012097:Repressor Proteins; C068477:ferric uptake regulating proteins, bacterial; C092412:neutrophil-activating protein A, Helicobacter pylori; D007501:Iron