Evidence of isochorismate channeling between the Escherichia coli enterobactin biosynthetic enzymes EntC and EntB.

ABSTRACT: Enterobactin is a high-affinity iron chelator produced and secreted by Escherichia coli and Salmonella typhimurium to scavenge scarce extracellular Fe³⁺ as a micronutrient. EntC and EntB are the first two enzymes in the enterobactin biosynthetic pathway. Isochorismate, produced by EntC, is a substrate for EntB isochorismatase. By using a competing isochorismate-consuming enzyme (the E. coli SEPHCHC synthase MenD), we found in a coupled assay that residual EntB isochorismatase activity decreased as a function of increasing MenD concentration. In the presence of excess MenD, EntB isochorismatase activity was observed to decrease by 84%, indicative of partial EntC-EntB channeling (16%) of isochorismate. Furthermore, addition of glycerol to the assay resulted in an increase of resid

SUBMITTER: Bin X 

PROVIDER: S-EPMC11258883 | biostudies-literature | 2024 Aug

REPOSITORIES: biostudies-literature