Disease relevance of katB

• The amino acid sequence of the P. aeruginosa katB was approximately 65% identical to that of a catalase from a related species, Pseudomonas syringae [1].
• Identification of a non-haem catalase in Salmonella and its regulation by RpoS (sigmaS) [2].
• When cloned into a catalase-deficient mutant of Escherichia coli (UM255), the recombinant P. aeruginosa KatB was expressed (229 U/mg) and afforded this strain resistance to hydrogen peroxide nearly equivalent to that of the wild-type E. coli strain (HB101) [1].
• Of the other pseudomonads, many produced proteinase, esterase, and catalase, several were able to grow at 42 degrees C and reduce nitrate, and some also produced lipase and hemolysin and, like P. aeruginosa, might serve to initiate (or sustain) the dermatitis frequently associated with fleece rot in sheep [3].
• Consortia of catalase positive bacteria consisting of Pseudomonas aeruginosa, Pseudomonas fluorescens, and Klebsiella pneumoniae, in both the planktonic form and as biofilms, disproportionate hydrogen peroxide into oxygen and water [4].

High impact information on katB

• The same concentrations also disturbed other aspects of the bacterium's iron metabolism, manifested by reduced cellular levels of cytochromes and catalase. beta-lactams, except for cefotaxime, and ciprofloxacin did not reduce alginate excretion [5].
• The ability of reducing agents and catalase to suppress the temperature-sensitive phenotype and of catalase to partially suppress antibiotic sensitivity suggested that increased levels of reactive oxygen species might be the cause of the observed phenotypes [6].
• A KatN recombinant protein, containing six histidine residues at its C-terminus, was purified, and its catalase activity was observed on a non-denaturing polyacrylamide gel [2].
• Mutants devoid of one or both autoinducers were more sensitive to hydrogen peroxide and phenazine methosulphate, and some PAI mutant strains also demonstrated decreased expression of two superoxide dismutases (SODs), Mn-SOD and Fe-SOD, and the major catalase, KatA [7].
• Exposure of P. aeruginosa to hyperoxia (100% O2) for 1 h increased superoxide dismutase, catalase, and glutathione levels [8].

Chemical compound and disease context of katB

• A Pseudomonas aeruginosa oxyR mutant was dramatically sensitive to H(2)O(2), despite possessing wild-type catalase activity [9].
• Defects in a quinol oxidase lead to loss of KatC catalase activity in Pseudomonas aeruginosa: KatC activity is temperature dependent and it requires an intact disulphide bond formation system [10].
• The cells of a newly isolated neomycin sensitive and neomycin resistant strains of Pseudomonas aeruginosa contained similar level of catalase activity [11].

Biological context of katB

• RNase protection and KatB- and AnkB-LacZ translational fusion analyses indicated that katB and ankB are part of a small operon whose transcription is induced dramatically by H(2)O(2), and controlled by the global transactivator OxyR [12].
• Reporter gene data obtained with a katB::lacZ transcriptional reporter strain confirmed katB induction and that the increase in total cellular catalase activity was attributable to KatB [13].
• When provided on a multicopy plasmid, the P. aeruginosa katA gene complemented a catalase-deficient strain of Escherichia coli [14].
• A protease-resistant catalase, KatA, released upon cell lysis during stationary phase is essential for aerobic survival of a Pseudomonas aeruginosa oxyR mutant at low cell densities [9].
• Catalase activity assays, activity stains in nondenaturing polyacrylamide gels, and lacZ reporter genes were used to characterize the oxidative stress responses of planktonic cultures and biofilms [13].

Anatomical context of katB

• The locations of cytochrome c peroxidase and catalase activities in the two Gram-negative bacteria Pseudomonas stutzeri (N.C.I.B. 9721) and Paracoccus denitrificans (N.C.I.B. 8944) were investigated by the production of spheroplasts [15].
• To better understand biofilm physiology, we examined possible explanations for the differential expression of catalase in cells cultured in these two different conditions [16].
• The amine oxidase appeared to be soluble and localized in the periplasm, but catalase and NAD-dependent aromatic aldehyde dehydrogenase, enzymes catalysing the conversion of its reaction products, were found in the cytoplasm [17].

Associations of katB with chemical compounds

• When provided in trans and expressed constitutively, the OxyR-regulated genes katB, ahpB, and ahpCF could not restore both the serial dilution defect and H(2)O(2) resistance; only oxyR itself could do so [9].
• Under culture conditions of limited phosphate, both pyocyanin production and catalase activity were enhanced [18].
• Nitrate-respiring planktonic cultures produced approximately twice as much catalase activity as aerobic cultures grown in the presence of nitrate; the nitrate stimulation effect could also be demonstrated in biofilms [16].
• Iron deprivation by the addition of the iron chelator 2,2'-dipyridyl to wild-type bacteria produced an increase in Mn-SOD activity and a decrease in total catalase activity, similar to the fur mutant phenotype [19].
• Cultures fermenting arginine had reduced catalase levels; however, catalase repression was also observed in aerobic cultures grown in the presence of arginine [16].

Other interactions of katB

• Planktonic cultures and biofilms formed by the wild-type strain PAO1 and the katA and katB catalase mutants were compared for their susceptibility to H(2)O(2) [13].

Analytical, diagnostic and therapeutic context of katB

• The penetration of hydrogen peroxide into biofilms formed by wild-type and catalase-deficient Pseudomonas aeruginosa strains was measured using microelectrodes [20].

References