Glucan 1,4-alpha-maltosyltransferase (GlgE) (GlgE)

Bifidobacterium longum alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase, commonly referred to as GlgE, is a key enzyme in the maltose-1-phosphate (M1P) pathway for alpha-glucan synthesis [UniProt: B7GQN1]. It catalyzes the elongation of glycogen-like polymers by transferring maltosyl units from M1P to the non-reducing ends of glucan chains [PMID: 21252313]. This enzyme is essential for carbohydrate storage and energy metabolism in B. longum, a beneficial probiotic inhabitant of the human gut [PMID: 17101331]. Although B. longum is not a pathogen, its GlgE enzyme is a significant structural homolog of the GlgE found in Mycobacterium tuberculosis [PMID: 23430108]. In mycobacteria, GlgE is a validated therapeutic target because its inhibition causes a toxic buildup of M1P, leading to rapid bacterial cell death [PMID: 21252313]. Research into B. longum GlgE is primarily focused on ensuring the selectivity of antitubercular drugs to avoid disrupting the commensal gut microbiota [PMID: 25631058]. Currently, there are no approved drugs that target the B. longum version of this enzyme, though experimental inhibitors are used in biochemical studies. The enzyme serves as an important model for understanding the evolution and function of the M1P pathway across different Actinobacteria. Its role in maintaining the fitness of probiotic bacteria makes it a factor in overall gastrointestinal health and microbiome stability.

Other names

Bifidobacterium longum alpha-1,4-glucan:maltose-1-phosphate maltosyltransferaseMaltosyltransferase1,4-alpha-D-glucan:maltose-1-phosphate maltosyltransferaseAlpha-1,4-glucan:maltose-1-phosphate maltosyltransferase

Inhibition of the maltose-1-phosphate pathway to prevent alpha-glucan synthesis and induce substrate-mediated toxicity