N-Acetylglucosamine 6-phosphate

Sulzenbacher, G., Gal, L., Peneff, C., Fassy, F., and Bourne, Y. (2001). Crystal structure of Streptococcus pneumoniae N-acetylglucosamine-1-phosphate uridyl transferase bound to acetyl-coenzyme A reveals a novel active site architecture. J. Biol. Chem. 276, 11844-11851. 

Polysaccharide-1-phosphates were extracted in some cases from bacterial cell walls. For example, TA isolated from Staphylococcus lactis 2102 consists of ca. 23 monomeric fragments each built of a-D-N-acetylglucosamine-1 -phosphate 22). These units are linked by the phosphoester bond at the 6 position in the sugar residue, as represented by 7. 

Formation of starting materials for cell wall synthesis begins with two metabolic substances normally found in all life forms N-acetylglucosamine 1-phosphate and the pyrimidine nucleotide uridine triphosphate (UTP) (see Fig. 6-3). Condensation of these two compounds by elimination of pyrophosphate affords uridine-diphospho-N-acetylglucosamine (UDPNAG). Reaction with phosphoenolpyruvic acid (PEP, the activated form of the enol tautomer of pyruvic acid),5 catalyzed by a specific transferase, yields the 3-O-enolic ether. 

Formation of UDP-N-acetylglucosamine from N-acetylglucosamine 1-phosphate is catalyzed by a pyrophosphorylase which appears to be distinct from UDP-glucose pyrophosphorylase, but the reaction has not been studied in any detail. 

The transformations leading up to N-acetylglucosamine 1-phosphate are shown below. 

The enzyme(s) which activates N-acetylglucosamine-1-phosphate is representative of a class of enzymes first described by Kornberg (1950) and Schrecker and Kornberg (1950). These enzymes catalyzed the synthesis or breakdown of unsymmetrical phosphoanhydrides ... 

Kostrewa D, D Arcy A, Takacs B et al (2001) Crystal structures of Streptococcus pneumoniae N-acetylglucosamine-l-phosphate uridyltransferase, GlmU, in apo form at 2.33 A resolution and in complex with UDP-N-acetylglucosamine and Mg(2+) at 1.96 A resolution. J Mol Biol 305 279-289... 

N-Acetylglucosamine 2-epimerase, N-ACYLGLUCOSAMINE 3-EPIMERASE N-ACETYLGLUCOSAMINE KINASE N-Acetyl-D-glucosamine 1-phosphate, PHOSPHOACETYLGLUCOSAMINE MUTASE... 

CDG-Ij UDP-GlcNAc dolichol phosphate N-acetylglucosamine-phosphotransferase 1 DPAGT1 1 lq23 608093... 

NADP+ NADPH NAG NAM Nicotinamide dinucleotide phosphate (oxidised form) Nicotinamide dinucleotide phosphate (reduced form) (3 - N- Acetylglucosamine ( - /V- A ce ty 1 m u r a m i c acid... 

The allyl group played a key role in a synthesis of a phosphorylated and glycosylated peptide fragment of mammalian RNS polymerase II.48 The allyl group was selected for the protection of both the phosphate and amino group of the terminal serine of the hexapeptide 26 1 [Scheme 7.26], because its reductive cleavage with butylammonium formate and Pd(0) could be accomplished without elimination of the phosphate or N-acetylglucosamine units attached to the three serine residues. 

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