UDP-N-acetylmuramic acid

One of the compounds formed from UDP-GlcNAc is UDP-N-acetylmuramic acid. The initial step in its synthesis is an unusual type of displacement reaction on the a-carbon of PEP by the 3-hydroxyl group of the sugar (Eq. 20-6, step a).40410 Inorganic phosphate is... 

Figure 3 Schematic representation of the cytoplasmic steps of biosynthesis of UDP-N-acetylmuramic acid pentapeptide in E. coli. UDP-NAcGlc, UDP-N-acetylglucosamine PEP, phosphoenolpyruvate UDP-NAcEPGlc, UDP-N-acetylenolpyruvylglucosamine UDP-NAcMur, UDP-N-acetylmuramic acid meso-DAV, meso-diaminopimelic acid.

Formation of UDP-N-acetylmuramic acid pentapeptide stage 1 of peptidoglycan biosynthesis. The steps in this pathway are discussed in the text. MurNAc = N-acetylmuramic acid, PEP = phosphoenolpyruvate. 

UDP-N-acetylglucosamine is a precursor of UDP-N-acetylmuramic acid in biosynthesis of UDP-N-acetylmuramylpentapeptide for bacteria cell walls. 

UDP-N-acetylmuramic acid is made from UDP-N-acetylglucosamine (see Figure) on the pathway to synthesis of UDP-N-acetylmuramyl pentapeptide for bacteria cell walls (Figure 16.19, Figure... 

UDP-N-acetylmuramyl pentapeptide is derived from UDP-N-acetylmuramic acid by the sequential addition of the following groups, L-alanine, D-glutamate, L-Lysine, D-Dlanine, D-Alanine (Figure... 

In the first stage of peptidoglycan synthesis, UDP-N-acetylmuramic acid is synthesized, and then a pentapeptide chain becomes attached to the carboxyl group of N-acetylmuramic acid (see Scheme 2). Strom-inger found that the reaction of enolpyruvate phosphate with UDP-2-acetamido-2-deoxy-D-glucose results in the formation of a compound that appeared to be a UDP-2-acetamido-2-deoxy-D-glucose-pyruvate enol ether, and he predicted that its reduction would aflFord UDP-N-acetylmuramic acid. The occurrence of these reactions has now been confirmed, and the intermediate product has been characterized in greater detail. ... 

UDP-N-acetylmuramic acid. The enzymes involved are highly specific, and the sequence of the amino acids is determined solely by the substrate and acceptor specificities of these enzymes, which require a divalent cation and ATP. One exception to the rule of sequential addition is the terminal dipeptide sequence, D-alanyl-D-alanine this dipeptide is first assembled and then transferred to the UDP-N-acetylmuramyl-tripeptide (see Scheme 2). 

EPSP synthase appears to be unique in that, unlike all other PEP-utilizing enzymes studied, PEP is bound as the second substrate. This has a clear mechanistic link in that generally glyphosate does not inhibit enzymes utilizing PEP as a substrate. The only close analogy to the EPSP synthase-catalyzed reaction is found with UDP-N-acetylmuramic acid (UDP-NAM) synthase. Like EPSP synthase, this enzyme also transfers the enolpyruvyl... 

Babic, A. and Pecar, S. (2007) An improved total synthesis of UDP-N-acetylmuramic acid. Tetrahedron Lett., 48, 4403-4405. 

---