Download MendeleyStructural basis for the acyl chain selectivity and mechanism of UDP-N-acetylglucosamine acyltransferase
Williams, A.H., Raetz, C.R.H.(2007) Proc Natl Acad Sci U S A 104: 13543-13550
- PubMed: 17698807
- DOI: https://doi.org/10.1073/pnas.0705833104
- Primary Citation of Related Structures:
2QIA, 2QIV - 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.
Organizational Affiliation:
Department of Biochemistry, Duke University Medical Center, Box 3711 DUMC, Durham, NC 27710, USA.
