Genetic basis for expression of the major globotetraose-containing lipopolysaccharide from H. influenzae strain Rd (RM118)

Abstract

A genetic basis for the biosynthetic assembly of the globotetraose containing lipopolysaccharide (LPS) of Haemophilus influenzae strain RM118 (Rd) was determined by structural analysis of LPS derived from mutant strains. We have previously shown that the parent strain RM118 elaborates a population of LPS molecules made up of a series of related glycoforms differing in the degree of oligosaccharide chain extension from the distal heptose residue of a conserved phosphorylated inner-core element, L--D-Hepp-(12)-L-- D-Hepp-(13)-[-D-Glcp-(14)-]-L--D-Hepp-(15)--Kdo. The fully extended LPS glycoform expresses the globotetraose structure, -D-GalpNAc-(13)--D-Galp-(14)--D-Galp-(14)--D-Glcp.