FIG. 1.

LOS structures of H. ducreyi strains 35000HP, 33921, and 35000HP-RSM2. The core and lipid A regions of the LOS structures are indicated. The conserved portions of the LOS are shown in boldface. The N-acetylglucosamine glycosyltransferase, LgtA, the galactosyltransferase, LbgA, and the heptosyltransferase, LbgB, are shown at their points of action. The 35000HP LOS structure is labeled with the previously developed nomenclature for the various LOS glycoforms (5). The three core heptoses (Hep) are l-glycero-d-manno-heptose; the branch heptose, in italics, is of the d-glycero-d-manno configuration.