Two distinct catalytic strategies in the hepatitis δ virus ribozyme cleavage reaction.

ABSTRACT: The hepatitis delta virus (HDV) ribozyme and related RNAs are widely dispersed in nature. This RNA is a small nucleolytic ribozyme that self-cleaves to generate products with a 2',3'-cyclic phosphate and a free 5'-hydroxyl. Although small ribozymes are dependent on divalent metal ions under biologically relevant buffer conditions, they function in the absence of divalent metal ions at high ionic strengths. This characteristic suggests that a functional group within the covalent structure of small ribozymes is facilitating catalysis. Structural and mechanistic analyses have demonstrated that the HDV ribozyme active site contains a cytosine with a perturbed pK(a) that serves as a general acid to protonate the leaving group. The reaction of the HDV ribozyme in monovalent cations alone never a

SUBMITTER: Golden BL 

PROVIDER: S-EPMC3220057 | biostudies-literature | 2011 Nov

REPOSITORIES: biostudies-literature