Escherichia coli deltafur mutant displays low HPII catalase activity in stationary phase.
Iron is among the most important micronutrients used by bacteria. As a partner of the Fenton reaction, however, iron potentiates oxygen toxicity. Strict regulation of iron metabolism, and its coupling with regulation of defenses against oxidative stress, is an essential factor for life in the presence of oxygen. In Escherichia coli, iron metabolism is regulated by the Fur protein. A Fur-deficient mutant, in stationary phase, displayed about 30y-fold lower HPII activity than the respective, Fur-proficient parental strain. Deletion of fur seems to affect HPII catalase specifically, since the mutant was capable of inducing HPI catalase when challenged with H(2)O(2). Low HPII catalase activity appears to be among the reasons for hydrogen peroxide hypersensitivity of the deltafur mutant.
Department of Biochemistry, Faculty of Medicine, Kuwait University, Kuwait. lbenov@hsc.kuniv.edu.kw
Ludmil
L
Benov
Fatima
F
Sequeira
D001426:Bacterial Proteins / Q000378:metabolism; D002374:Catalase / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism*; D002474:Cell-Free System; D002478:Cells, Cultured; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000494:pharmacology; D007501:Iron / Q000378:metabolism*; D009154:Mutation; D010100:Oxygen / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism; D012808:Sigma Factor / Q000378:metabolism; D013997:Time Factors
D001426:Bacterial Proteins; D012097:Repressor Proteins; D012808:Sigma Factor; C068477:ferric uptake regulating proteins, bacterial; C069567:sigma factor KatF protein, Bacteria; D006861:Hydrogen Peroxide; D007501:Iron; C102664:hydroperoxidase II; D002374:Catalase; D005980:Glutathione Reductase; D010100:Oxygen