EC 3.2 Glycosylases
This subclass contains the glycosylases, which are classified as hydrolases, although some of them can also transfer glycosyl residues to oligosaccharides, polysaccharides and other alcoholic acceptors. The glycosylases are subdivided into glycosidases, i.e., enzymes that hydrolyse O- and S-glycosyl compounds (EC 3.2.1) and those that hydrolyse N-glycosyl compounds (EC 3.2.2). Common names for enzymes acting on D-sugars or their derivatives do not normally contain 'D', unless ambiguity would result from the common existence of the corresponding L-sugar. Enzymes that hydrolyse a terminal, non-reducing-end glycose (or a well-defined di-, tri- or oligosaccharide) from a glycan, i.e. exoenzymes, are given systematic names based on 'glycohydrolase'; enzymes that hydrolyse internal glycosidic bonds, i.e. endoenzymes, are given systematic names based on 'glycanohydrolase'. The same structure is often used when providing accepted names for these enzymes.