08.08.2015   Biomass Recalcitrance

GDP-$ — L-galactose (GDP-Gal)

GDP-$-L-gluclose gulose (GDP-Gul)

GDP-Gal is a major precursor for the synthesis of ascorbic acid in plants, and relatively low amounts of L-Gal are found in plant glycans. A GDP-Man 3′,57 epimerase activity first identified in the Neufeld’s laboratory (493) epimerizes GDP-Man into GDP-Gal. Careful biochemical analyses of the specific activity of recombinant Arabidopsis At5g28840 (494) and rice (497) protein demonstrate that the enzyme can convert GDP-Man to both GDP-Gul and GDP-Gal (496). A crystal structure of the enzyme was recently obtained (497).