OH

O

CH2

COO-

COO-

OHCOO-

O

COO-

OH

COO-

NH3+

COO-

COO-

NH3+

COO-

Chorismate Mutase (CM1)

Prephenate Aminotransferase (PNT)

Arogenate Dehydratase (ADT)

Chorismate

Prephenate

Arogenate

Phenylalanine

Phenylalanine Ammonia Lyase (PAL)NH4+

Glutamine Synthetase (GS)

Glutamate

-Ketoglutarate

CO2, H2O

Glutamine

Glutamate

Glutamine

Glutamate

Glutamate Synthase (GOGAT)

Vanillin

Shikimate Pathway (7 enzymes)

2x Phosphoenolpyruvate + Erythrose 4-phosphate

ATP, NADPH

ADP, NADP , 4x Pi

ATP

ADP + Pi

NAD(P)H or 2 Fdx-

NAD(P) or 2 Fdx

? Cinnamate

+

+

Figure S2. Phenylalanine biosynthesis.The first commited step of phenylalanine biosynthesis is the rearrangement of chorismate by chorismate mutase to form prephenate. The nitrogen that is incorporated into arogenate is supplied by the GS-GOGAT cycle. When linked with phenylpropanoid biosynthesis, this nitrogen is supplied by ammonia released by phenylalanine ammonia lyase. It has also been suggested that this nitrogen is used downstream in benzenoid metabolism. Cofactors are to the left of the reaction arrows and enzymes are to the right. Abbreviations are as follows: ferrodoxin (Fdx) and ammonia (NH4

+). Sources: Siehl, 1999; Cho et al., 2007, http://www.kegg.com