Evolution of functional diversity as observed through structural studies of glutathione transferases

Most enzymes bind specifically to one or to a few closely related substrate s. However, this is not the case for the enzyme superfamily of glutathione S-transferases (GSTs). The enzyme's ability to recognise a diverse range of substrates is due, in part, to the existence of isoforms. We have determin ed the crystal structures of GSTs from four classes and from a diverse rang e of organisms ranging from bacteria to human, These studies are revealing the molecular basis and evolutionary development of how GSTs recognise and react with a structurally diverse array of toxins. (C) 2001 Elsevier Scienc e Ireland Ltd. All rights reserved.