Cytochrome P450 monooxygenase: part of the gene cluster that mediates the biosynthesis of domoic acid (DA) and derivatives, natural products with neurochemical activity acting as ionotropic glutamate receptor (iGluR) agonists, thus being neurotoxins causing amnesic shellfish poisoning (ASP) (PubMed:30262498). Catalyzes the conversion of N-geranyl-L-glutamic acid (L-NGG) to N-(7'-carboxy-7'-demethylgeranyl)-L-glutamic acid (cNGG) via three successive steps involving N-(8'-hydroxygeranyl)-L-glutamic acid and N-(8'-oxogeranyl)-L-glutamic acid as intermediates (PubMed:30262498). N-geranyl-L-glutamate + O2 + reduced [NADPH--hemoprotein reductase] = H(+) + H2O + N-(8'-hydroxygeranyl)-L-glutamate + oxidized [NADPH--hemoprotein reductase] N-(8'-hydroxygeranyl)-L-glutamate + O2 + reduced [NADPH--hemoprotein reductase] = H(+) + 2 H2O + N-(8'-oxogeranyl)-L-glutamate + oxidized [NADPH--hemoprotein reductase] N-(8'-oxogeranyl)-L-glutamate + O2 + reduced [NADPH--hemoprotein reductase] = 2 H(+) + H2O + N-(7'-carboxy-7'-demethylgeranyl)-L-glutamate + oxidized [NADPH--hemoprotein reductase] Secondary metabolite biosynthesis. Up-regulated under phosphate limitation and by increasing partial pressure of CO(2). Belongs to the cytochrome P450 family.