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 2.5.1.57) 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:
References:
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]