FIG. 4.

Proposed structure of LPS I of R. etli CE3 (16, 17). Features affected in mutants CE166 and CE395 are noted. Designation as O antigen is arbitrarily assigned to all contiguous residues released with the Kdo most distal to lipid A after mild hydrolysis that cleaves at Kdo residues (16, 23). Chemical analysis indicates that Fuc residues are only partially O-methylated at the positions shown (16). R, the various hydroxyfatty acyl groups that are ester- and amide-linked at the positions indicated in the lipid A portion; TOMFuc, tri-O-methylated Fuc; 3M6dTal, 3-O-methyl-6-deoxytalose; QuiNAc, N-acetylquinovosamine; GlcON, 2-aminogluconate. All other abbreviations are defined in Table 2.