Four Isoforms of Arabidopsis 4-Coumarate:CoA Ligase Have Overlapping yet Distinct Roles in Phenylpropanoid Metabolism.

The biosynthesis of lignin, flavonoids, and hydroxycinnamoyl esters share the first three enzymatic steps of the phenylpropanoid pathway. The last shared step is catalyzed by 4-coumarate:CoA ligase (4CL), which generates p-coumaroyl CoA and caffeoyl CoA from their respective acids. Four isoforms of 4CL have been identified in Arabidopsis (Arabidopsis thaliana).