Galactose-6-phosphate isomerase (LacAB) (LacAB)

Galactose-6-phosphate isomerase is a critical enzyme in the tagatose-6-phosphate pathway, which serves as the primary route for galactose catabolism in various lactic acid bacteria, including the probiotic species Lactobacillus rhamnosus (UniProt: P0C1U8, P0C1U9) [1]. The enzyme typically functions as a heterodimer consisting of LacA and LacB subunits that catalyze the reversible isomerization of D-galactose 6-phosphate into D-tagatose 6-phosphate (EC 5.3.1.26) [2]. This metabolic step is vital for the bacterium's ability to utilize galactose, a sugar commonly found in dairy products and the human gut environment, thereby supporting its growth and competitive fitness within the microbiome [3]. While this enzyme is essential for the physiological robustness and colonization efficiency of Lactobacillus rhamnosus, it is not currently utilized as a therapeutic target for pharmaceutical intervention in human disease. Research into this enzyme primarily focuses on microbial fermentation processes and the optimization of probiotic strains to enhance gastrointestinal health [4]. There are no known drugs that target this specific bacterial enzyme for clinical use.

Other names

Galactose-6-phosphate isomerase subunit LacAGalactose-6-phosphate isomerase subunit LacBGal6P isomeraseD-galactose-6-phosphate isomeraseLacticaseibacillus rhamnosus galactose-6-phosphate isomerase