Functional analysis of a lipid galactosyltransferase synthesizing the major envelope lipid in the Lyme disease spirochete Borrelia burgdorferi.
2007 (English)In: FEMS Microbiol Lett, ISSN 0378-1097, Vol. 272, no 1, 22-9 p.Article in journal (Other academic) Published
One of the major lipids in the membranes of Borrelia burgdorferi is
monogalactosyl diacylglycerol (MGalDAG), a glycolipid recently shown to carry
antigenic potency. Herein, it is shown that the gene mgs (TIGR designation
bb0454) of B. burgdorferi encodes for the protein bbMGS that, when expressed in
Escherichia coli, catalyzes the glycosylation of 1,2-diacylglycerol with
specificity for the donor substrate UDP-Gal yielding MGalDAG. Related lipid
enzymes were found in many Gram-positive bacteria. The presence of this
galactosyltransferase activity and synthesis of a cholesteryl galactoside by
another enzyme were verified in B. burgdorferi cell extract. Besides MGalDAG,
phosphatidylcholine, phosphatidylglycerol, and cholesterol were also found as
major lipids in the cell envelope. The high isoelectric point of bbMGS and
clustered basic residues in its amino acid sequence suggest that the enzyme
interacts with acidic lipids in the plasma membrane, in agreement with strong
enzymatic activation of bbMGS by phosphatidylglycerol. The membrane packing and
immunological properties of MGalDAG are likely to be of great importance in vivo.
Place, publisher, year, edition, pages
2007. Vol. 272, no 1, 22-9 p.
Bacterial Proteins/genetics/*metabolism, Borrelia burgdorferi/*enzymology/genetics, Cell Membrane/chemistry, Cholesterol/analysis/isolation & purification, Cloning; Molecular, Diglycerides/*biosynthesis/metabolism, Enzyme Activators/analysis/isolation & purification/pharmacology, Escherichia coli/genetics/metabolism, Galactolipids/*metabolism, Galactosyltransferases/genetics/*metabolism, Genes; Bacterial, Isoelectric Point, Lipid Metabolism, Membrane Lipids/*biosynthesis, Phosphatidylcholines/analysis/isolation & purification, Phosphatidylglycerols/analysis/isolation & purification/pharmacology, Recombinant Proteins/genetics/metabolism, Sequence Analysis; Protein, Transcription; Genetic, Uridine Diphosphate Galactose/metabolism
IdentifiersURN: urn:nbn:se:su:diva-12062ISI: 000247317000004PubMedID: 17456185OAI: oai:DiVA.org:su-12062DiVA: diva2:178582