Serine biosynthesis starts from 3-phosphoglycerate (3PG), a glycolysis intermediate. Its dehydrogenation to 3-phosphonooxypyruvic acid (3POPA) is catalysed by tetrameric phosphoglycerate dehydrogenase (PHGDH). (Tabatabaie et al. 2009).
van den Berg, IE,
de Koning, TJ
phosphoglycerate dehydrogenase activity of PHGDH tetramer [cytosol]