2QIA

Structural basis for the acyl chain selectivity and mechanism of UDP-N-acetylglucosamine Acyltransferase

Summary for 2QIA

• Entry DOI: 10.2210/pdb2qia/pdb
• Related: 2QIV
• Descriptor: UDP-N-acetylglucosamine acyltransferase, uridine-5'-diphosphate-3-O-(R-3-hydroxymyristoyl)-N-acetyl-D-glucosamine (3 entities in total)
• Functional Keywords: left-handed parallel beta helix, transferase
• Biological source: Escherichia coli K12
• Cellular location: Cytoplasm: P0A722
• Total number of polymer chains: 1
• Total formula weight: 28950.73

Authors

Williams, A.H.,Raetz, C.R.H. (deposition date: 2007-07-03, release date: 2007-10-02, Last modification date: 2023-08-30)

Primary citation

Williams, A.H.,Raetz, C.R.H.
Structural basis for the acyl chain selectivity and mechanism of UDP-N-acetylglucosamine acyltransferase
Proc.Natl.Acad.Sci.Usa, 104:13543-13550, 2007

PubMed Abstract: UDP-N-acetylglucosamine (UDP-GlcNAc) acyltransferase (LpxA) catalyzes the first step of lipid A biosynthesis, the reversible transfer of the R-3-hydroxyacyl chain from R-3-hydroxyacyl acyl carrier protein to the glucosamine 3-OH group of UDP-GlcNAc. Escherichia coli LpxA is highly selective for R-3-hydroxymyristate. The crystal structure of the E. coli LpxA homotrimer, determined previously in the absence of lipid substrates or products, revealed that LpxA contains an unusual, left-handed parallel beta-helix fold. We have now solved the crystal structures of E. coli LpxA with the bound product UDP-3-O-(R-3-hydroxymyristoyl)-GlcNAc at a resolution of 1.74 A and with bound UDP-3-O-(R-3-hydroxydecanoyl)-GlcNAc at 1.85 A. The structures of these complexes are consistent with the catalytic mechanism deduced by mutagenesis and with a recent 3.0-A structure of LpxA with bound UDP-GlcNAc. Our structures show how LpxA selects for 14-carbon R-3-hydroxyacyl chains and reveal two modes of UDP binding.

PubMed: 17698807
DOI: 10.1073/pnas.0705833104

Experimental method

X-RAY DIFFRACTION (1.74 Å)