Prediction of hammerhead ribozyme intracellular activity with the catalytic core fingerprint

Hammerhead ribozyme is a versatile tool for down-regulation of gene expression in vivo. Due to its small size and high activity, it is used as a model for RNA structure-function relationship studies. Here we describe a new extended hammerhead ribozyme HH-2 with a tertiary stabilizing motif constructed on the basis of the tetraloop receptor sequence. This ribozyme is very active in living cells but shows low activity in vitro. To understand it, we analyzed tertiary structure models of substrate:ribozyme complexes. We calculated six unique catalytic core geometry parameters as distances and angles between particular atoms that we call the ribozyme fingerprint. A flanking sequence and tertiary motif change the geometry of the general base, general acid, nucleophile and the leaving group. We found almost complete correlation between these parameters and the decrease of target gene expression in the cells. The tertiary structure model calculations allow us to predict ribozyme intracellular activity. Our approach could be widely adapted to characterize catalytic properties of other RNAs.

Source: BJ Gene - February 19, 2013 Category: Biochemistry Authors: M Magdalena Gabryelska, E Wyszko, M Szymański, M Popenda, J Barciszewski Tags: BJ Gene Source Type: research