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Enzymatic synthesis of 8‐amino‐3,8‐dideoxy‐D‐manno‐oct‐2‐ulsonic acid (Kdo8N)‐lipid A in Shewanella
Author(s) -
Gattis Samuel Guy,
Raetz Christian R.H.
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.940.3
Subject(s) - lipid a , shewanella oneidensis , biochemistry , bacterial outer membrane , lipopolysaccharide , bacteria , shewanella , chemistry , microbiology and biotechnology , amino acid , enzyme , gram negative bacteria , escherichia coli , biology , gene , genetics , endocrinology
The outer membrane of gram‐negative bacteria is primarily composed of lipopolysaccharide (LPS), the hydrophobic anchor of which is lipid A. Lipid A, also known as endotoxin, serves as the permeability barrier for gram‐negative bacteria as well as activating the innate immune system in infection. Modifications to the conserved substructure Kdo 2 ‐lipid A in diverse bacteria have been shown to influence virulence, antibiotic resistance, and immune response. Here we report the discovery of the Shewanella oneidensis genes required for 8‐amino‐3,8‐dideoxy‐D‐ manno ‐oct‐2‐ulsonic acid (Kdo8N) biosynthesis. Overexpression of a gene cluster of unknown function from S. oneidensis in E. coli resulted in production of (Kdo8N) 2 ‐lipid A, as judged by mass spectrometry and thin‐layer chromatography. The relevant genes were previously annotated as an Fe‐dependent alcohol dehydrogenase and an aspartate aminotransferase, suggesting a two‐step mechanism in which the 8‐OH of Kdo is first oxidized to an aldehyde, followed by transamination to form a primary amine at C8. In vitro enzymology and homologues from the pathogen Leptospira interrogans are being investigated. This work was supported by NIH GM51796 to C.R.H.R. and Lipid Maps GM069338.