Dirigent proteins impart stereoselectivity on the phenoxy radical-coupling reaction, yielding optically active lignans from two molecules of coniferyl alcohol in the biosynthesis of lignans, flavonolignans, and alkaloids and thus plays a central role in plant secondary metabolism. Enantiocomplementary dirigent protein that mediates the laccase-catalyzed enantioselective oxidative phenol coupling of (E)-coniferyl alcohol to (-)-pinoresinol. Homodimer. Confined to shoot meristem, vascular region of cotyledons and siliques abscission zone. Belongs to the plant dirigent protein family.