FIG 1.

Scheme of the proposed transcriptional regulation of anaerobic degradation of p-cresol by the predicted σ⁵⁴-dependent two-component system PcrSR in the denitrifying bacterium Aromatoleum aromaticum EbN1. Compound names: 1, p-cresol; 2, p-hydroxybenzaldehyde; 3, p-hydroxybenzoate; 4, p-hydroxybenzoyl-CoA. Enzyme names: Cmh, FAD-dependent p-cresol methylhydroxylase; Hbd, p-hydroxybenzaldehyde dehydrogenase; Hcl2, 4-hydroxybenzoate CoA ligase. HTH, helix-turn-helix; 4VR, 4-vinyl-reductase; PAS, Per-Arnt-Sim; UBS, putative upstream binding sequence of PcrR; XylR, regulatory protein of the Pseudomonas TOL plasmid.