DNAzymes cleave at predetermined sequences within RNA. A prerequisite for cleavage is that the DNAzyme can gain access to its target, and thus the DNAzyme must be capable of unfolding higher-order structures that are present in the RNA substrate. However, in many cases the RNA target sequence is hidden in a region that is too tightly structured to be accessed under physiological conditions by DNAzymes.
The Nucleic Acid Center, Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark. b.vester@bmb.sdu.dk
