Fig. 7

Overview of P. xenovorans physiological response during 4-HPA catabolism in presence of FldX1. 4-HPA enters the cell through a transmembrane protein and is catabolized via homoprotocatechuate and homogentisate degradation pathways. The preferred route, homogentisate, generates ROS via the MhaAB enzyme, during an enzymatic reaction facilitated by FldX1, which serves as electron shuttle. This is reflected by a downregulation of the antioxidant response (antioxidant proteins and genes), enhancing bacterial fitness. The long-chain flavodoxin FldX1 acts as electron shuttle between sources of reducing power and metabolic pathways. Green arrows indicate upregulation of genes/proteins, while red arrows indicate downregulation. OM, outer membrane, PS, periplasmic space, IM, inner membrane