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ENZYME entry: EC

Accepted Name
UDP-N-acetylglucosamine 4,6-dehydratase (inverting).
Alternative Name(s)
UDP-N-acetylglucosamine 5-inverting 4,6-dehydratase.
Reaction catalysed
UDP-N-acetyl-alpha-D-glucosamine <=> UDP-2-acetamido-2,6-dideoxy-beta-L-arabino-hex-4-ulose + H(2)O
  • The first enzyme in the biosynthetic pathway of pseudaminic acid, a sialic-acid-like sugar that is unique to bacteria and is used by Helicobacter pylori to modify its flagellin.
  • Plays a critical role in H.pylori's pathogenesis, being involved in the synthesis of both functional flagella and lipopolysaccharides.
  • Completely inhibited by UDP-alpha-D-galactose.
  • The reaction results in the chirality of the C-5 atom being inverted.
  • It is thought that Lys-133 acts sequentially as a catalytic acid, protonating the C-6 hydroxy group and as a catalytic base, abstracting the C-5 proton, resulting in the elimination of water.
PRIAM enzyme-specific profiles4.2.1.115
KEGG Ligand Database for Enzyme Nomenclature4.2.1.115
IUBMB Enzyme Nomenclature4.2.1.115
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