costunolide synthase activity
Catalysis of the reaction: germacra-1(10),4,11(13)-trien-12-oate + O2 + NADPH + 2 H+ = costunolide + 2 H2O + NADP.
GO:0016712
oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced flavin or flavoprotein as one donor, and incorporation of one atom of oxygen
is_a