This data base contains the three-dimensional structures of GlycosylTransferases (GTs) that have been crystallized without or with their carbohydrate ligands. Links are available to access the information about the original article (Medline) and related structural information (PDB). See Guide for information about the Data Base content, the Data Query, the Simple Search and the Advanced search options. The “Display and Download Menu” requires the Jmol applet to be installed.