1,3-beta-glucan synthase (Fks1 (for *Saccharomyces cerevisiae* and many fungi))

1,3-beta-glucan synthase is an integral membrane glycosyltransferase complex responsible for catalyzing the formation of 1,3-beta-glucan, a major structural polysaccharide of most fungal cell walls. In *Saccharomyces cerevisiae* and most pathogenic fungi, the principal component is Fks1, a large, multi-pass transmembrane protein with a central glycosyltransferase (GT-A) domain (CAZy family GT48) and a transmembrane channel that exports synthesized glucan. The enzyme uses UDP-glucose as substrate to build β-1,3-glycosidic linkages, contributing to cell wall rigidity and osmotic stability. Its activity is regulated by Rho1 GTPase, and drugs targeting this enzyme (like echinocandins and ibrexafungerp) interrupt glucan synthesis, leading to cell wall defects and cell death, making it a validated and clinically important antifungal drug target.

Other names

β-1,3-glucan synthasebeta-1,3-glucan synthaseGSFks1Gls1Gls2Gls3GLS (family)1,3-β-glucan synthase

Inhibition of β-1,3-glucan synthesis, leading to weakened fungal cell wall and cell lysis