CATH Classification

Domain Context

CATH Clusters

Superfamily NAD(P)-binding Rossmann-like Domain
Functional Family UDP-N-acetylglucosamine 4,6-dehydratase (inverting)

Enzyme Information
UDP-N-acetylglucosamine 4,6-dehydratase (inverting).
based on mapping to UniProt O25511
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.

UniProtKB Entries (1)

Helicobacter pylori 26695
UDP-N-acetylglucosamine 4,6-dehydratase (inverting)

PDB Structure

External Links
Organism Escherichia
Primary Citation
Structural Studies of FlaA1 from Helicobacter pylori Reveal the Mechanism for Inverting 4,6-Dehydratase Activity.
Ishiyama, N., Creuzenet, C., Miller, W.L., Demendi, M., Anderson, E.M., Harauz, G., Lam, J.S., Berghuis, A.M.