3hydroxybenzoylCoA

3hydroxybenzoyl-CoA is an intermediate metabolite involved in bacterial aromatic amino acid catabolism, particularly in the degradation pathways of phenylalanine, tyrosine, and tryptophan. It plays a central role in the β-ketoadipate pathway, a key route for the breakdown of aromatic compounds in microorganisms such as *Pseudomonas* species and other gram-negative bacteria.

The compound consists of a 3hydroxybenzoyl group covalently linked to coenzyme A (CoA) via a thioester bond. Its formation typically occurs through the oxidative cleavage of aromatic rings, where enzymes like 3-oxoadipate enol-lactone hydrolase or related oxygenases facilitate the conversion of aromatic substrates into this intermediate. The subsequent steps involve further oxidation and ring contraction, ultimately leading to the formation of 3-oxoadipate enol-lactone, which is then hydrolyzed to 3-oxoadipate.

3hydroxybenzoyl-CoA is metabolized via the action of the 3hydroxybenzoyl-CoA oxygenase complex, an enzyme system that incorporates molecular oxygen to introduce hydroxyl groups and facilitate ring cleavage. This process generates intermediates that enter central metabolic pathways, such as the tricarboxylic acid (TCA) cycle, where they are further oxidized to produce energy and biosynthetic precursors.

The pathway is of ecological and biotechnological significance, as it enables bacteria to utilize aromatic compounds as carbon and energy sources, contributing to soil organic matter decomposition and bioremediation efforts. Genetic and enzymatic studies of this pathway have also provided insights into microbial adaptation to aromatic pollutants and the evolution of metabolic versatility in prokaryotes.