Activating the d-Tagatose Production Capacity of <i>Escherichia coli</i> with Structural Insights into C4 Epimerase Specificity.

ABSTRACT: d-Tagatose, a rare low-calorie sweetener, is ideal for beverages due to its high solubility and low viscosity. Current enzymatic production methods from d-galactose or d-galactitol are limited by reaction reversibility, affecting the yield and purity. This study demonstrates that Escherichia coli harbors a thermodynamically favorable pathway for producing d-tagatose from d-glucose via phosphorylation-epimerization-dephosphorylation steps. GatZ and KbaZ, annotated as aldolase chaperones, exhibit C4 epimerization activity, converting d-fructose-6-phosphate to d-tagatose-6-phosphate. Structural analysis reveals active site differences between these enzymes and class II aldolases, indicating functional divergence. By exploiting the strains' inability to metabolize d-tagatose, carbon sta

SUBMITTER: Palur DSK 

PROVIDER: S-EPMC11907403 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature