Fig. 8
Molecular oxidative stress response of P. xenovorans LB400 during exposure to paraquat and H2O2. Green arrows indicate upregulation of genes and/or proteins, while red arrows indicate downregulation. Dashed arrows indicate the transport of O2, H2O2 and paraquat through the cell membranes. Dotted arrow indicates Fenton reaction, a process during which metal ions (mainly Fe2+) react with H2O2 forming hydroxyl radical. Glucose is converted into gluconate 6-phosphate (gluconate-6P) by glucokinase and the Pentose Phosphate (PP) pathway. Blue arrow indicates the transformation of the gluconate-6P to glyceraldehyde-3-phosphate (G3P) and pyruvate via the Entner–Doudoroff pathway. Purple arrow indicates the conversion of G3P into pyruvate via the lower Embden–Meyerhof–Parnas (EMP) pathway. OM outer membrane, PS periplasmic space, IM inner membrane, FumC/fumC fumarate hydratase C, AcnB aconitate hydratase, hpf high potential Fe-S protein, trxB1 thioredoxin 1, trxB2 thioredoxin 2, fpr flavodoxin/ferredoxin NADP oxidoreductase, sodB1 superoxide dismutase, DnaK GroEL and GroES, molecular chaperones, Hsp20 heat shock protein, UspA universal stress protein, ahpC1D1 and ahpC2F alkyl hydroperoxide reductases, katE catalase, DpsA ferritin protein of the DPS family, Gst/gstA1 glutathione S-transferase, Ohr organic hydroperoxide resistance protein, OhrR organic hydroperoxide resistance transcriptional regulator, MetF 5,10-methylenetetrahydrofolate reductase