Glycoside hydrolases: Catalytic base/nucleophile diversity

Recent studies have shown that a number of glycoside hydrolase families do not follow the classical catalytic mechanisms, as they lack a typical catalytic base/nucleophile. A variety of mechanisms are used to replace this function, including substrate‐assisted catalysis, a network of several residues, and the use of non‐carboxylate residues or exogenous nucleophiles. Removal of the catalytic base/nucleophile by mutation can have a profound impact on substrate specificity, producing enzymes with completely new functions. Biotechnol. Bioeng. 2010;107: 195–205. © 2010 Wiley Periodicals, Inc.