FIGURE 4.

Auto-oxidation of the product of BacA. a, product obtained by the activity of BacA on prephenate is prone to oxidation upon prolonged incubation. The spectroscopic profile of this product resembles that of BacB. Here, (■), prephenate alone incubated for 12 h; (▴), BacA with prephenate incubated for 12 h; (●), BacA and BacB with prephenate incubated for 15 min. b, reference UV spectra of potential substrates and products of the Bac proteins. (■), 4-hydroxy phenylpyruvic acid, (⊗), l-phenylalanine; (○), dl-tryptophan; (●), prephenate; (◊), l-tyrosine, (★), phenylpyruvic acid.