Structural highlights
Function
[A0A0S7E9S6_9EURO] Catalyzes the conversion of GlcNAc-6-P into GlcNAc-1-P during the synthesis of uridine diphosphate/UDP-GlcNAc, which is a biosynthetic precursor of chitin and also supplies the amino sugars for N-linked oligosaccharides of glycoproteins.[PIRNR:PIRNR016408]
Publication Abstract from PubMed
N -acetylphosphoglucosamine mutase (AGM1) is a key component of the hexosamine biosynthetic pathway that produces UDP-GlcNAc, an essential precursor for a wide range of glycans in eukaryotes. AGM belongs to the a-D-phosphohexomutase metalloenzyme superfamily and catalyses the interconversion of N -acetylglucosamine-6-phosphate (GlcNAc-6P) to N -acetylglucosamine-1-phosphate (GlcNAc-1P) through N -acetylglucosamine-1,6-bisphosphate (GlcNAc-1,6-bisP) as the catalytic intermediate. Although there is an understanding of the phosphoserine-dependent catalytic mechanism at enzymatic and structural level, the identity of the requisite catalytic base in AGM1/phosphoglucomutases is as yet unknown. Here we present crystal structures of a Michaelis complex of AGM1 with GlcNAc-6P and Mg(2+), and a complex of the inactive Ser69Ala mutant together with glucose-1,6-bisphosphate (Glc-1,6-bisP) that represent key snapshots along the reaction coordinate. Together with mutagenesis, these structures reveal that the phosphate group of the hexose-1,6-bisP intermediate may act as the catalytic base.
Evidence for substrate assisted catalysis in N-acetylphosphoglucosamine mutase.,Raimi OG, Hurtado Guerrero R, van Aalten DM Biochem J. 2018 Jul 2. pii: BCJ20180172. doi: 10.1042/BCJ20180172. PMID:29967067[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Raimi OG, Hurtado Guerrero R, van Aalten DM. Evidence for substrate assisted catalysis in N-acetylphosphoglucosamine mutase. Biochem J. 2018 Jul 2. pii: BCJ20180172. doi: 10.1042/BCJ20180172. PMID:29967067 doi:http://dx.doi.org/10.1042/BCJ20180172
