Identification of a novel lipopolysaccharide core biosynthesis gene cluster in Bordetella pertussis, and influence of core structure and lipid A glucosamine substitution on endotoxic activity.
Lipopolysaccharide (LPS), also known as endotoxin, is one of the main constituents of the gram-negative bacterial outer membrane. Whereas the lipid A portion of LPS is generally considered the main determinant for endotoxic activity, the oligosaccharide moiety plays an important role in immune evasion and the interaction with professional antigen-presenting cells. Here we describe a novel four-gene cluster involved in the biosynthesis of the Bordetella pertussis core oligosaccharide. By insertionally inactivating these genes and studying the resulting LPS structures, we show that at least two of the genes encode active glycosyltransferases, while a third gene encodes a deacetylase also required for biosynthesis of full-length oligosaccharide. In addition, we demonstrate that mutations in the locus differentially affect LPS and whole-cell endotoxic activities. Furthermore, while analyzing the mutant LPS structures, we confirmed a novel modification of the lipid A phosphate with glucosamine and found that inactivation of the responsible glycosyltransferase reduces the endotoxic activity of the LPS.
Geurtsen
Jeroen
J
Department of Molecular Microbiology, Utrecht University, 3584 CH Utrecht, The Netherlands.
Dzieciatkowska
Monika
M
Steeghs
Liana
L
Hamstra
Hendrik-Jan
HJ
Boleij
Johanna
J
Broen
Kelly
K
Akkerman
Grietsje
G
El Hassan
Hassan
H
Li
Jianjun
J
Richards
James C
JC
Tommassen
Jan
J
van der Ley
Peter
P
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001886:Bordetella pertussis / Q000235:genetics* / Q000378:metabolism*; D002460:Cell Line; D055786:Gene Knockout Techniques; D023061:Gene Order; D005798:Genes, Bacterial; D005944:Glucosamine / Q000378:metabolism*; D016695:Glycosyltransferases / Q000235:genetics / Q000378:metabolism; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000096:biosynthesis* / Q000737:chemistry / Q000276:immunology*; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D015394:Molecular Structure; D009000:Monocytes / Q000187:drug effects / Q000276:immunology; D005810:Multigene Family; D016254:Mutagenesis, Insertional
D001426:Bacterial Proteins; D015850:Interleukin-6; D008070:Lipopolysaccharides; D016695:Glycosyltransferases; D005944:Glucosamine