IUBMB Enzyme Nomenclature


Accepted name: 3-deoxy-D-glycero-D-galacto-nononate 9-phosphate synthase

Reaction: phosphoenolpyruvate + D-mannose 6-phosphate + H2O = 3-deoxy-D-glycero-D-galacto-non-2-ulopyranosonate 9-phosphate + phosphate

Glossary: phosphoenolpyruvate = 2-(phosphooxy)prop-2-enoate
3-deoxy-D-glycero-D-galacto-nononate = Kdn

Other name(s): 2-keto-3-deoxy-D-glycero-D-galacto-9-phosphonononic acid synthase; Kdn 9-P synthase

Systematic name: phosphoenolpyruvate:D-mannose-6-phosphate 1-(2-carboxy-2-oxoethyl)transferase

Comments: The enzyme participates in the biosynthesis of the sialic acid 3-deoxy-D-glycero-D-galacto-nononate (Kdn). The human sialic acid synthase (EC is also able to catalyse the reaction. KDN is abundant in extracellular glycoconjugates of lower vertebrates such as fish and amphibians, but is also found in the capsular polysaccharides of bacteria that belong to the Bacteroides genus.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:


1. Angata, T., Nakata, D., Matsuda, T., Kitajima, K. and Troy, F.A., 2nd. Biosynthesis of KDN (2-keto-3-deoxy-D-glycero-D-galacto-nononic acid). Identification and characterization of a KDN-9-phosphate synthetase activity from trout testis. J. Biol. Chem. 274 (1999) 22949-22956. [PMID: 10438460]

2. Lawrence, S.M., Huddleston, K.A., Pitts, L.R., Nguyen, N., Lee, Y.C., Vann, W.F., Coleman, T.A. and Betenbaugh, M.J. Cloning and expression of the human N-acetylneuraminic acid phosphate synthase gene with 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid biosynthetic ability. J. Biol. Chem. 275 (2000) 17869-17877. [PMID: 10749855]

3. Wang, L., Lu, Z., Allen, K.N., Mariano, P.S. and Dunaway-Mariano, D. Human symbiont Bacteroides thetaiotaomicron synthesizes 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid (KDN). Chem. Biol. 15 (2008) 893-897. [PMID: 18804026]

[EC created 2016]

Return to EC 2.5.1 home page
Return to EC 2.5 home page
Return to EC 2 home page
Return to Enzymes home page
Return to IUBMB Biochemical Nomenclature home page