Enzyme - UDP-N-acetylglucosamine diphosphorylase

Alternative Name(s)
  • N-acetylglucosamine-1-phosphate uridyltransferase.
  • UDP-N-acetylglucosamine pyrophosphorylase.

Catalytic Activity

H(+) + N-acetyl-alpha-D-glucosamine 1-phosphate + UTP = diphosphate + UDP-N-acetyl-alpha-D-glucosamine


There are no Cofactors for this Enzyme

Reaction Mechanism

    The bifunctional enzyme GlmU is able to catalyse two steps in the pathway of bacterial cell wall synthesis:

    1. The C-terminal domain converts glucosamine-1-phosphate to N-acetyl glucosamine-1-phosphate using Acetyl CoA as the donor
    2. The N-terminal domain (this entry) utilises UTP to activate the N-acetyl glucosamine-1-phosphate forming UDP-acetyl-glucosamine and pyrophosphate.

    Interest in the processes catalysed by this enzyme stems from its potential as an antibiotic target.

    The mechanism of the transfer of UDP to N acetylglucosamine-1-phosphate proceeds via nucleophilic attack from the phosphate oxygen of the phosphate moiety on the alpha phosphate producing a pentavalent phosphate transition state. This is stabilised by Mg2+ at the active site and Arg 18, and collapses to release the beta and gamma phosphates as pyrophosphate.
    Catalytic Residues
    AA Uniprot Uniprot Resid PDB PDB Resid
    Arg P0ACC7 18 1hv9 18
    Step Components

    overall reactant used, overall product formed, proton transfer, bimolecular nucleophilic substitution, inferred reaction step

    Step 1.

    The phosphate of N-acetyl-alpha-D-glucosamine 1-phosphate attacks the alpha phosphate of UTP. This releases diphosphate and forms the product.

    Step 2.

    The diphosphate group is protonated. The proton may be sourced from the solvent.


    The products of the reaction.

Reaction Parameters

There are no kinetic parameters information for this Enzyme

Associated Proteins

Protein name Organism
UDP-N-acetylglucosamine pyrophosphorylase Yeast
Probable UDP-N-acetylglucosamine pyrophosphorylase Fission yeast
Bifunctional protein GlmU Escherichia coli (strain K12)
UDP-N-acetylhexosamine pyrophosphorylase Human
UDP-N-acetylglucosamine diphosphorylase 1 Mouse-ear cress