tailieunhanh - Báo cáo khoa học: Efficient RNA ligation by reverse-joined hairpin ribozymes and engineering of twin ribozymes consisting of conventional and reverse-joined hairpin ribozyme units

In recent years major progress has been made in elucidating the mechanism and structure of catalytic RNA molecules, and we are now beginning to understand ribozymes well enough to turn them into useful tools. Work in our laboratory has focused on the development of twin ribozymes for site-specific RNA sequence alteration. To this end, we followed a strategy that relies on the combination of two ribozyme units into one molecule (hence dubbed twin ribozyme). | iFEBS Journal Efficient RNA ligation by reverse-joined hairpin ribozymes and engineering of twin ribozymes consisting of conventional and reverse-joined hairpin ribozyme units Sergei A. Ivanov Stephanie Vauleon and Sabine Muller Ruhr-Universitat Bochum Bochum Germany Keywords rationaldesign RNA catalysis RNA ligation sequence alteration twin ribozyme Correspondence S. Muller Ruhr-Universitat Bochum Fakultat Chemie Universitatsstrasse 150 D-44780 Bochum Germany Fax 49 234 321 4783 Tel 49 234 322 7034 E-mail Received 13 June 2005 accepted 15 July 2005 doi In recent years major progress has been made in elucidating the mechanism and structure of catalytic RNA molecules and we are now beginning to understand ribozymes well enough to turn them into useful tools. Work in our laboratory has focused on the development of twin ribozymes for sitespecific RNA sequence alteration. To this end we followed a strategy that relies on the combination of two ribozyme units into one molecule hence dubbed twin ribozyme . Here we present reverse-joined hairpin ribozymes that are structurally optimized and which in addition to cleavage catalyse efficient RNA ligation. The most efficient variant ligated its appropriate RNA substrate with a single turnover rate constant of min-1 and a final yield of 70 . We combined a reverse-joined hairpin ribozyme with a conventional hairpin ribozyme to create a twin ribozyme that mediates the insertion of four additional nucleotides into a predetermined position of a substrate RNA and thus mimics at the RNA level the repair of a short deletion mutation 17 of the initial substrate was converted to the insertion product. In recent years RNA has become the focus of development into new diagnostic and therapeutic schemes. Antisense-RNA ribozyme aptamer and siRNA technologies have been developed and have found application in molecular medicine 1-7 . Signalling aptamers and aptazymes have been .