Ribozymes Essay -- Biology, Catalytic Molecules, RNA

Ribozymes are catalytic molecules that cleave the ribonucleic acid (RNA) at specific sequences (Gesteland et al. 2006). RNA is the nucleic acid that is made in the process of transcription; when the deoxyribonucleic acid (DNA) anneals, it transcribes itself into a linear stranded molecule called RNA. In order for RNA to synthesise proteins, it requires catalytic enzymes to perform certain chemical reactions. In the past, it was thought that all chemical reactions are catalysed by protein enzymes; however, in the eighties this hypothesis was disproved as Thomas Cech and Sydney Altman discovered that RNA is able to carry out self-catalysing activities which were named as ribozymes because they perform similar functions as the protein enzymes (Jaeger, 1997). Even though, RNA ribozymes lack the functional groups diversity found in protein enzymes, they are able to carry out their own catalytic reactions due to their tendency to fold into a 3D structure and form helices by Watson-Crick ba se pairing role (Kiehntopf et al. 1995). Ribozymes are now play critical role in the understanding of biochemistry, as they have the ability to catalyse some of the most important chemical reactions such as RNA splicing as well as the synthesis of peptides, for instance ribozymes can speed up the phosphoryl transfer chemical reactions by 1011 folds. This review will describe the structure, sources and applications of ribozymes. There are several naturally occurring ribozymes that have been identified to date; these are divided into three distinct classes. Firstly, the self splicing introns that fall into groups I and II respectively depending on their structure and the recognition sequences. Self splicing group I intron was the first ribozyme to b... ...the cells, the localisation of the ribozymes in the cells as well as the selection site of the messengerRNA (James and Gibson, 1998). Ribozymes are currently considered to hold many promises for the future development of gene therapy as they have the ability to splice and cleave any target RNA sequences. There are seven natural ribozymes known and several artificial ribozymes have been created. These artificial ribozymes are being used as therapeutic agent to target the aberrant gene expression in many lethal diseases such as cancer. The limitation of artificial ribozymes is mainly due to the difficulty in their delivery to the target cells. Therefore, more research needs to be conducted in thoroughly studying the organisation and structures of the natural RNA ribozymes to achieve successful artificial ribozymes that have complex function in the future.