<p>UDP-3-O-N-acetylglucosamine deacetylases are zinc-dependent metalloamidases that catalyse the second and committed step in the biosynthesis of lipid A. Lipid A anchors lipopolysaccharide (the major constituent of the outer membrane) into the membrane in Gram negative bacteria. LpxC shows no homology to mammalian metalloamidases and is essential for cell viability, making it an important target for the development of novel antibacterial compounds [<cite idref="PUB00032543"/>]. The structure of UDP-3-O-N-acetylglucosamine deacetylase (LpxC) from <taxon tax_id="63363">Aquifex aeolicus</taxon> has a two-layer alpha/beta structure similar to that of the second domain of ribosomal protein S5, only in LpxC there is a duplication giving two structural repeats of this fold, each repeat being elaborated with additional structures forming the active site. LpxC contains a zinc-binding motif, which resides at the base of an active site cleft and adjacent to a hydrophobic tunnel occupied by a fatty acid [<cite idref="PUB00029703"/>]. This tunnel accounts for the specificity of LpxC toward substrates and inhibitors bearing appropriately positioned 3-O-fatty acid substituents [<cite idref="PUB00035690"/>]. </p><p>This entry represents the N-terminal domain.</p> UDP-3-O-acyl N-acetylglucosamine deacetylase, N-terminal