UDP-N-acetylglucosamine O-acyltransferase (UDP-GlcNAc acyltransferase): Proteins in this family catalyze the transfer of (R)-3-hydroxymyristic acid from its acyl carrier protein thioester to UDP-GlcNAc. It is the first enzyme in the lipid A biosynthetic pathway and is also referred to as LpxA. Lipid A is essential for the growth of Escherichia coli and related bacteria. It is also essential for maintaining the integrity of the outer membrane. UDP-GlcNAc acyltransferase is a homotrimer of left-handed parallel beta helix (LbH) subunits. Each subunit contains an N-terminal LbH region with 9 turns, each containing three imperfect tandem repeats of a hexapeptide repeat motif (X-[STAV]-X-[LIV]-[GAED]-X), and a C-terminal alpha-helical region.
Comment:Active UDP-N-acetylglucosamine acyltransferase is trimeric, with active sites located at the interface between two LbH subunits. The trimer structure contains three active sites and each subunit contributes to two active sites via residues located on two surfaces.
Comment:The structure evidences show only the interaction of substrate to one interacting LbH subunit/surface.
Structure:2QIV_X; Escherichia coli UDP-N-acetylglucosamine acyltransferase binds UDP-3-O-(R-3-hydroxymyristoyl)-GlcNAc; defined at 3.5A contacts.
Jiyao W et al.(2023). "The conserved domain database in 2023.",