Multi-enzyme cascade reactions synthesize diverse structurally defined glycoside conjugates.

Protein glycosylation serves essential biological functions. While glycosyltransferases catalyze protein glycosylation, their practical applications are limited by the dependence on high-cost nucleotide sugar donors. In this work, we bypass these nucleotide sugar intermediates and develop a coupled biocatalytic system with monosaccharide donors, allowing economical synthesis of structurally defined glycoconjugates.