pyridoxal 5'-phosphate biosynthesis pathway UPa:UPA00245 de novo vitamin B6 biosynthesis (PdxS/PdxT pathway) Biosynthesis of pyridoxal 5'-phosphate. This pathway corresponds to one of the de novo biosynthesis pathway. The biosynthesis of PLP is performed by a complex reaction: in addition to ammonia transfer PdxS/PdxT catalyzes condensation of two phosphosugars, closure of the pyridine ring, as well as isomerase reactions for its phosphosugar substrates. The complexity of the enzyme correlates well with the strong conservation of the PdxS sequence. Contrary to the alternative PLP biosynthesis pathway (glutamate pathway), this pathway does not require PLP as cofactor in its own synthesis. de novo vitamin B6 biosynthesis (glutamine pathway) PLP biosynthesis de novo vitaminB6 biosynthesis (PDX1/PDX2 pathway) GO:0042823 cofactor biosynthesis