Thymidine Diphosphate 4-Keto-6-deoxy-d-glucose, an Intermediate in Thymidine Diphosphate l-Rhamnose Synthesis in Escherichia coli Strains

Abstract

Several thymidine diphosphate sugar compounds have recently been discovered in a number of microorganisms.TDPrhamnose was isolated from Lactobacillus acidophilus R-26 (2) and Escherichia coli B (3).Four unidentified TDP-sugar compounds were also found in E. coli: TDP-X, TDP-Y, and TDP-Z in E. coli Y-10 (4) and TDP-X2 in E. coli B (3).Following the discovery of these new thymidine nucleotides, the enzymatic synthesis of TDP-glucose from oc-o-glucose l-phosphate and TTP and its enzymatic conversion to TDP-rhamnose have been reported in Streptococcus jaecalis (5) and Pseudomonas aeruginosa (6, 7).In addition, TDP-mannose as well as TDP-rhamnose have been reported to occur in Streptomyces griseus (8).In this paper, evidence will be presented that TDP-Y, isolated from E. coli Y-10, is an intermediate in the pathway of biosynthesis of TDP-r-rhsmnose from TDP-n-glucose.In addition, this intermediate has been isolated after its enzymatic synthesis from TDP-n-glucose.It has been identified as TDP-4-keto-6-deoxy-n-glucose.This keto sugar was also obtained from extracts of P. aeruginosa incubated with TDPn-glucose (677).The identification of TDP-Z, another TDP-sugar compound found in E. coli Y-10, will also be reported.