Hammerhead ribozyme is a self RNA cleavage enzyme

Although people used to think that only proteins have enzymatic activities, recently many RNA having an enzymatic activity has been discovered, which are called ribozyme. The hammerhead ribozyme is a self RNA cleavage enzyme, which means that this RNA showing an unique hammerhead-like secondary structure breaks its own phosphodiester bond of nucleotide within the cleavage site of its RNA sequence. We utilize this enzyme for experiments of molecular biology, especially in case of constructing an artificial RNA. By placing the hammerhead ribozyme coding sequence within the objective RNA producing plasmid, we can cut the synthesized RNA at the optimal position.