FIG. 3.

General structure of LPS in S. enterica serovar Typhimurium and roles of both ddhC and waaG in LPS synthesis. (A) Structure of Salmonella LPS with the sites affected by ddhC and waaG mutations identified. (B) LPS electrophoretic profiles of the A1-8 (ddhC::Tn5) and A1-9 (waaG::Tn5) mutants of S. enterica serovar Typhimurium DT104 showing the production of low-molecular-weight LPS compared with the ladder pattern of WT strain Rv. (C) A profile of LPS alteration similar to that of A1-9 was shown in the waaG knockout strain of the WT LT2 strain, YA155, which was complemented to the WT phenotype in strain YA156 by plasmid-borne waaG. The production of low-molecular-weight LPS in mutants further confirmed the roles of both ddhC and waaG in determining the structure of LPS. Proteinase K-treated whole-cell lysates were prepared from cells growing in early log phase at 37°C in LB, run on an SDS-PAGE gel, and silver stained. Abe, abequose; Kdo, 2-keto-3-deoxyoctulosonic acid.