Functional characterization of a novel <i>p</i> -coumarate 3-hydroxylase from <i>Trametes versicolor</i>

White-rot fungi are key players in the global carbon cycle through lignin degradation, yet the intracellular pathways that catabolize lignin-derived aromatics remain largely unresolved. The hydroxyphenyl unit compound <i>p</i>-coumaric acid (<i>p</i>-CA) is a major lignin fragment, but the enzymes responsible for its conversion to caffeic acid (CFA) have not been previously identified in fungi. This study demonstrates that <i>Trametes versicolor</i> employs group A flavoprotein monooxygenases (FPMOs) <i>Tv</i>MNX3 and <i>Tv</i>MNX4 for the hydroxylation of <i>p</i>-CA and related metabolites, representing an unrecognized branch of the <i>p</i>-CA catabolic pathway. Beyond ecological significance, the capacity of <i>Tv</i>MNX4 to generate bioactive phenolics such as CFA and piceatannol underscores its potential for biotechnological applications, including the sustainable synthesis of pharmaceuticals and polymer precursors.