Figure 2

Simplified thiamin biosynthesis and model simulation results. (a) Simplified thiamin biosynthesis. THIC (4-amino-2-methyl-5-hydroxymethylpyrimidine phosphate (HMP-P) synthase) mediates the synthesis of HMP-P and THI1 (4-methyl-5-b-hydroxyethylthiazole phosphate (HET-P) synthase) of HET-P. HMP-P is phosphorylated into HMP-PP by the action of the bifunctional HMP-P kinase/TP synthase (TH1) which subsequently condenses HMP-PP and HET-P to form thiamin monophosphate (TMP). (b) Simulation results for TMP production along time in the non-optimized model (dark grey—Normal conditions; overexpression THIC: −··−; overexpression THI1: ····; overexpression TH1: – – –; and overexpression TH1, THIC and THI1 simultaneously—black).