Abstract
Glycosyltransferases (GTs) are ubiquitous in nature and are required for the transfer of sugars to a variety of important biomolecules. This essential enzyme family has been a focus of attention from both the perspective of a potential drug target and a catalyst for the development of vaccines, biopharmaceuticals and small molecule therapeutics. This review attempts to consolidate the emerging lessons from Leloir (nucleotide-dependent) GT structural biology studies and recent applications of these fundamentals toward rational engineering of glycosylation catalysts.