The conformational plasticity of glycosyltransferases.

Glycosyltransferases (GTs) catalyze the transfer of a sugar moiety from nucleotide-sugar or lipid-phospho-sugar donors to a broad range of acceptor substrates, generating a significant amount of structural diversity in biological systems. GTs are highly selective in nature, allowing the recognition of subtle structural differences in the sequences and stereochemistry of their sugar and acceptor substrates. To achieve the enzyme-transition state complex, a particular spatial arrangement of the active site is required, highlighting the importance of protein dynamics, conformational changes and plasticity of GTs during substrate recognition and catalysis. The elucidations of the molecular mechanisms by which these events govern the function and substrate specificity of GTs represent a major challenge.