O-Glycoside hydrolases (EC 3.2.1.-) are enzymes that catalyze the cleavage of chemical bonds between two or more carbohydrates or between a carbohydrate and a non-carbohydrate moiety. This collaborative research will focus on approximately 75 members of two related families of glycoside hydrolases. 

     Family 1 includes ß-glucosidases (EC 3.2.1.21) and thioglucoside glucohydrolases (myrosinases; EC 3.2.3.1), which function in higher plants in chemical defense against herbivores and pathogens, lignin biosynthesis, and plant growth and development. Family 35 contains the ß-galactosidases (EC 3.2.1.23), which play key roles in fruit ripening, flower senescence, mobilization of carbohydrate reserves, and galactolipid turnover. The objective of this multidisciplinary research is to assign biological functions to every member of these two families. In parallel studies, three-dimensional structures of selected subfamily representatives will be determined by homology modeling and x-ray diffraction, providing novel insights into how these hydrolases recognize and bind their substrates. 

     This information will be of paramount importance in future research to alter the substrate specificity of Family 1 and Family 35 hydrolases for biotechnological purposes, including biomass conversion and improvements in anti-herbivore defenses and fruit ripening.