Structural basis of lipid binding for the membrane-embedded tetraacyldisaccharide-1-phosphate 4'-kinase LpxK.
Published
Journal Article
The membrane-bound tetraacyldisaccharide-1-phosphate 4'-kinase, LpxK, catalyzes the sixth step of the lipid A (Raetz) biosynthetic pathway and is a viable antibiotic target against emerging Gram-negative pathogens. We report the crystal structure of lipid IVA, the LpxK product, bound to the enzyme, providing a rare glimpse into interfacial catalysis and the surface scanning strategy by which many poorly understood lipid modification enzymes operate. Unlike the few previously structurally characterized proteins that bind lipid A or its precursors, LpxK binds almost exclusively to the glucosamine/phosphate moieties of the lipid molecule. Steady-state kinetic analysis of multiple point mutants of the lipid-binding pocket pinpoints critical residues involved in substrate binding, and characterization of N-terminal helix truncation mutants uncovers the role of this substructure as a hydrophobic membrane anchor. These studies make critical contributions to the limited knowledge surrounding membrane-bound enzymes that act upon lipid substrates and provide a structural template for designing small molecule inhibitors targeting this essential kinase.
Full Text
Duke Authors
Cited Authors
- Emptage, RP; Tonthat, NK; York, JD; Schumacher, MA; Zhou, P
Published Date
- August 29, 2014
Published In
Volume / Issue
- 289 / 35
Start / End Page
- 24059 - 24068
PubMed ID
- 25023290
Pubmed Central ID
- 25023290
Electronic International Standard Serial Number (EISSN)
- 1083-351X
Digital Object Identifier (DOI)
- 10.1074/jbc.M114.589986
Language
- eng
Conference Location
- United States