Three genes, lgtF, lic2C and lpsA, have a primary role in determining the pattern of oligosaccharide extension from the inner core of Haemophilus influenzae LPS.
Lipopolysaccharide (LPS) is a virulence determinant of Haemophilus influenzae and exhibits substantial heterogeneity in structure within and between strains. Key factors contributing to this heterogeneity are the genes required to add the first glycose to each of the three heptose residues of the LPS inner core. In each case this addition can facilitate further oligosaccharide extension. lgtF is invariably present in strains and the product has a function in adding the glucose to the first heptose. lic2C is present in half the strains and was found to add a glucose to the second heptose. Insertion of lic2C into a strain that does not naturally contain it resulted in hexose incorporation from the second heptose of the LPS. The product of the lpsA gene can add a glucose or galactose to the third heptose. By allelic replacement of lpsA between strains it is shown that the sequence of the gene can be the sole determinant of this specificity. Thus, lgtF, lic2C and lpsA make significant but very distinct contributions to the conservation and variable patterns of oligosaccharide extensions seen in H. influenzae LPS.
Hood
Derek W
DW
Molecular Infectious Diseases Group, University of Oxford Department of Paediatrics, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK.
Deadman
Mary E
ME
Molecular Infectious Diseases Group, University of Oxford Department of Paediatrics, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK.
Cox
Andrew D
AD
Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario, Canada, K1A 0R6.
Makepeace
Katherine
K
Molecular Infectious Diseases Group, University of Oxford Department of Paediatrics, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK.
Martin
Adele
A
Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario, Canada, K1A 0R6.
Richards
James C
JC
Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario, Canada, K1A 0R6.
Moxon
E Richard
ER
Molecular Infectious Diseases Group, University of Oxford Department of Paediatrics, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DS, UK.
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001770:Blood Bactericidal Activity; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D015964:Gene Expression Regulation, Bacterial; D005964:Glucosyltransferases / Q000235:genetics* / Q000378:metabolism; D006193:Haemophilus influenzae / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008070:Lipopolysaccharides / Q000096:biosynthesis* / Q000737:chemistry; D009844:Oligosaccharides / Q000096:biosynthesis*; D021241:Spectrometry, Mass, Electrospray Ionization
D001426:Bacterial Proteins; D008070:Lipopolysaccharides; D009844:Oligosaccharides; D005964:Glucosyltransferases