Posted: May 22nd, 2023

HTP undergoes an oxidative decarboxylation under the influence of enzyme

This biosynthetic route is well defined in E. coli. In this process, the substrate 3-hydroxyl-1-aminoacetone phosphate undergoes a four step synthetic pathway from D-erythrose 4-phosphate². In the first step, the compound is oxidated to D-erythronate 4-phosphate by its respective dehydrogenase enzyme (GapB), which uses NAD redox factor².

In the second step, the D-erythronoate 4-phosphte undergoes a process of oxidation under the action of its respective enzyme PdxB and the NAD cofactor to produce (3R)-3-hydroxy-2-oxo-4-phosphonooxybutanoate². Then, the enzyme PdxF catalyzes the PLP-dependent transmission from the product of the second oxidation to glutamate, which results into the formation of 4-hydroxy-L-threonine phosphate (HTP)².

Then, HTP undergoes an oxidative decarboxylation under the influence of enzyme PdxA to form 3-hydroxy-1-aminocetne phosphate. It is believed that the process takes place in two steps². First, alcohol undergoes a nicotinamide-dependent oxidation at the α-position. Secondly, the resulting α-ketoacid is decarboxylated to form the 3-hydroxy-1-aminocetne phosphate².