Abstract
Okazaki, Tuneko (Washington University School of Medicine, St. Louis, Mo.), Jack L. Stominger, and Reiji Okazaki. Thymidine diphosphate-l-rhamnose metabolism in smooth and rough strains of Escherichia coli and Salmonella weslaco. J. Bacteriol. 86:118-124. 1963.-Logarithmic-phase cells of Escherichia coli O18, which have rhamnose in their lipopolysaccharide, contained only traces of thymidine diphosphate (TDP)-l-rhamnose. Extracts of this organism, however, catalyzed the synthesis of TDP-l-rhamnose from TDP-d-glucose. On the other hand, cells of E. coli R44, a rough variant of this strain which contains no rhamnose in its lipopolysaccharide, contained a large amount of TDP-l-rhamnose. Like the smooth form, this organism was able to synthesize TDP-l-rhamnose. The rough variant is apparently a mutant blocked in some manner in utilization of TDP-l-rhamnose for lipopolysaccharide synthesis. Similar studies of smooth (rhamnose-containing) and rough (rhamnose-lacking) forms of Salmonella weslaco showed that both organisms can synthesize TDP-l-rhamnose from TDP-d-glucose. In contrast to the smooth and rough forms of E. coli O18, only traces of TDP-l-rhamnose were detected in extracts of both forms. A second thymidine diphosphosugar compound isolated from E. coli R44 is similar or identical to TDP-X, previously isolated from E. coli Y-10.