Catalysis by nucleoside hydrolases.

TitleCatalysis by nucleoside hydrolases.
Publication TypeJournal Article
Year of Publication2003
AuthorsVersées, W., and J. Steyaert
JournalCurr Opin Struct Biol
Volume13
Issue6
Pagination731-8
Date Published2003 Dec
ISSN0959-440X
KeywordsBinding Sites, Catalysis, Enzyme Activation, N-Glycosyl Hydrolases, Protein Binding, Protein Conformation, Protein Folding, Ribose, Structural Homology, Protein, Structure-Activity Relationship, Substrate Specificity
Abstract

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 JournalCurr. Opin. Struct. Biol.
PubMed ID14675552