|Title||Catalysis by nucleoside hydrolases.|
|Publication Type||Journal Article|
|Year of Publication||2003|
|Authors||Versées, W., and J. Steyaert|
|Journal||Curr Opin Struct Biol|
|Date Published||2003 Dec|
|Keywords||Binding Sites, Catalysis, Enzyme Activation, N-Glycosyl Hydrolases, Protein Binding, Protein Conformation, Protein Folding, Ribose, Structural Homology, Protein, Structure-Activity Relationship, Substrate Specificity|
Nucleoside hydrolases cleave the N-glycosidic bond of ribonucleosides. Because of their vital role in the protozoan purine salvage pathway, nucleoside hydrolases from parasitic protozoa in particular have been studied extensively by X-ray crystallography, kinetic methods and site-directed mutagenesis. An elaborate network of conserved interactions between the metalloenzyme and the ribose enables steric and electrostatic stabilisation of the oxocarbenium-ion-like transition state. Activation of the leaving group by protonation before the formation of the transition state is a recurring catalytic strategy of enzymes that cleave N-glycosidic bonds. However, the mechanisms underlying leaving group activation are still the subject of debate for the nucleoside hydrolases.
|Alternate Journal||Curr. Opin. Struct. Biol.|
Catalysis by nucleoside hydrolases.