Tyrosine Hydroxylation in Betalain Pigment Biosynthesis Is Performed by Cytochrome P450 Enzymes in Beets (Beta vulgaris)
Fig 3
All tested CYP76AD proteins perform tyrosine hydroxylation in yeast.
A. HPLC/ms analysis of yeast expressing CYP76AD1, CYP76AD6, and CYP76AD5 individually shows that all will hydroxylate tyrosine to L-DOPA. Inset shows expanded view of lower peaks. Yeast containing empty vector either have weak tyrosine hydroxylation activity or produce a compound that co-migrates with L-DOPA. B to F. Same yeast strains as in A with the addition of PgDODA. B. images of the cultures fed L-DOPA, tyrosine, or no added substrate with the tyrosine-fed panel corresponding to C through F. C and D. HPLC/MS analysis of the red betanidin pigment with the lower peaks for CYP76AD6, CYP76AD5, and empty vector expanded in D. E. and F. HPLC/MS analysis of the yellow tyrosine-betaxanthin pigment with the lower peaks for CYP76AD6, CYP76AD1, and empty vector expanded in F. Note that CYP76AD1 produces large amounts of betanidin and small amounts of betaxanthin. G. Yeast cultures expressing PgDODA alone and PgDODA with CYP76AD3 or CYP76AD15 from Mirabilis jalapa and fed tyrosine. CYP76AD3 has CYP76AD1-like activity producing red pigment and CYP76AD15 has CYP76AD6/5-like activity producing yellow pigment.