Figure 1
Artificial vanillin biosynthetic pathway constructed in Escherichia coli cells.
The purple part shows the reconstruction of the common aromatic pathway for l-tyrosine overproduction; the global regulatory protein TyrR has been inactivated and four enzymes are overexpressed. As shown in the pale blue part, three enzymes are involved in the artificial pathway from tyrosine to ferulic acid. Black part in the right box shows the three steps from ferulic acid to vanillin, which are catalyzed by two enzymes. TyrR, a regulatory protein; PEPS, phosphoenolpyruvate synthetase; TKT, transketolase; fbr-DAHPS, fbr-3-deoxy-d-arabino-heptulosonate-7-phosphate synthase; fbr-CM/PDH, fbr-chorismate mutase/prephenate dehydrogenase; TAL, tyrosine ammonia-lyase; C3H, 4-coumarate 3-hydroxylase; COMT, caffeate O-methyltransferase; FCS, trans-feruloyl-CoA synthetase; ECH, enoyl-CoA hydratase/aldolase. The orchid was drawn by Jun Ni.
