Pathway for lipid A biosynthesis in Arabidopsis thaliana resembling that of Escherichia coli.
Journal Article
The lipid A moiety of Escherichia coli lipopolysaccharide is a hexa-acylated disaccharide of glucosamine that makes up the outer monolayer of the outer membrane. Arabidopsis thaliana contains nuclear genes encoding orthologs of key enzymes of bacterial lipid A biosynthesis, including LpxA, LpxC, LpxD, LpxB, LpxK and KdtA. Although structurally related lipid A molecules are found in most other gram-negative bacteria, lipid A and its precursors have not been directly detected in plants previously. However, homozygous insertional knockout mutations or RNAi knock-down constructs of Arabidopsis lpx and kdtA mutants revealed accumulation (or disappearance) of the expected monosaccharide or disaccharide lipid A precursors by mass spectrometry of total lipids extracted from 10-day old seedlings of these mutants. In addition, fluorescence microscopy of lpx-gfp fusions in transgenic Arabidopsis plants suggests that the Lpx and KdtA proteins are expressed and targeted to mitochondria. Although the structure of the lipid A end product generated by plants is still unknown, our work demonstrates that plants synthesize lipid A precursors using the same enzymatic pathway present in E. coli.
Full Text
Duke Authors
Cited Authors
- Li, C; Guan, Z; Liu, D; Raetz, CRH
Published Date
- July 12, 2011
Published In
Volume / Issue
- 108 / 28
Start / End Page
- 11387 - 11392
PubMed ID
- 21709257
Pubmed Central ID
- 21709257
Electronic International Standard Serial Number (EISSN)
- 1091-6490
Digital Object Identifier (DOI)
- 10.1073/pnas.1108840108
Language
- eng
Conference Location
- United States