cd04727

PdxS is a subunit of the pyridoxal 5'-phosphate (PLP) synthase, an important enzyme in deoxyxylulose 5-phosphate (DXP)-independent pathway for de novo biosynthesis of PLP, present in some eubacteria, in archaea, fungi, plants, plasmodia, and some metazoa. Together with PdxT, PdxS forms the PLP synthase, a heteromeric glutamine amidotransferase (GATase), whereby PdxT produces ammonia from glutamine and PdxS combines ammonia with five- and three-carbon phosphosugars to form PLP. PLP is the biologically active form of vitamin B6, an essential cofactor in many biochemical processes. PdxS subunits form two hexameric rings.