Activating the d-Tagatose Production Capacity of with Structural Insights into C4 Epimerase Specificity.

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 harbors a thermodynamically favorable pathway for producing d-tagatose from d-glucose via phosphorylation-epimerization-dephosphorylation steps.