Handbook of Glycosyltransferases and Related Genes pp 1537-1543 | Cite as
N-Acetylneuraminic Acid Phosphatase (NANP)
N-acetylneuraminate 9-phosphate phosphatase (NANP) catalyzes the reaction: N-acetylneuraminic acid 9-phosphate (Neu5Ac-9-P)→N-acetylneuraminic acid (Neu5Ac) + phosphate. This enzyme is necessary only in animals. Neu5Ac-9-P, but not Neu5Ac, is the product of the condensation reaction of N-acetylmannosamine 6-phosphate (ManNAc-6-P) with phosphoenolpyruvate (PEP), catalyzed by the Neu5Ac-9-P synthase (NANS) in animals. Dephosphorylation of Neu5Ac-9-P by this enzyme is necessary to produce free Neu5Ac. In bacteria, Neu5Ac is directly synthesized from ManNAc and PEP, and no NANP is necessary. In animals Neu5Ac cannot be synthesized from ManNAc by the NANP. The NANP gene has not been reported in bacteria, although there reported the similar dephosphorylation enzyme, Kdo (2-keto-3-deoxy-D-manno-octurosonic acid) 8-phosphate phosphatase that is involved in the synthesis of Kdo in bacteria and plants, but not in animals. Interestingly, a human symbiont Bacteroides thetaiotaomicron has the 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid 9-phosphate (Kdn-9-P) phosphatase, which catalyzes the reaction: Kdn-9-P→Kdn + phosphate.
KeywordsSialic Acid Aspartic Acid Residue Enzyme Fraction Distal Myopathy Gene Target Experiment
- Ugochukwu E, Cocking R, Yue WW, Pike ACW, Roos A, Muniz JRC, Von Delft F, Bountra C, Arrowsmith CH, Weigelt J, Edwards A, Oppermann U. The crystal structure of human N-Acetylneuraminic Acid Phosphatase, Nanp. To be publishedGoogle Scholar
- Van Rinsum J, Van Dijk W, Hooghwinkel GJ, Ferwerda W (1984) Subcellular localization and tissue distribution of sialic acid-forming enzymes. N-acetylneuraminate-9-phosphate synthase and N-acetylneuraminate 9-phosphatase. Biochem J 223:323–328Google Scholar