Ribozyme technology

Ribozyme are ribosome which start work as enzyme.

1. RIBOZYME TECHNOLOGY Submitted to -: Dr.Monika Asthana Dept.of Biotechnology school of life science, DBRAU Agra. Submitted by-: Prashant sharma biotechnologist

2. INTRODUCTION Ribozyme technology deals with the use of ribozymes for different purposes including therapeutic and research purposes. RNA are the molecule which show catalytic activity.

3. HISTORY The first ribozyme was discovered in 1980. Reseachers demonstrating that RNA function both as a genetic material or as a biological catalyst. This contribute to the worldwide hypothesis that RNA may played a crucial role in the evolution of self-replicating systems. This reffered as RNA World Hypothesis.

4. RIBOZYME A ribozyme (ribonucleic acid enzyme) is an RNA molecule that is capable of performing specific biochemical reactions, similar to the action of protein enzymes. Ribozyme means ribonucleic acid enzyme. It also called an RNA enzyme or catalytic RNA It contains an active site that consists entirely of RNA

5. Catalytic activity Ribozymes are RNA molecules endowed with catalytic activity and capable of cleaving mRNA molecules in a sequence specific, catalytic manner. They contain sequences for selective ligation with target mRNAs which confers upon them high specificity. They also contain sequences that perform cleavage reactions with the target mRNA. By modifying the substrate recognizing sequences, ribozymes can be specifically tailored for the suppression of particular genes.

6. Catalytic Activity

7. Types of RIBOZYMES Natural ribozymes can be classified into two different groups: 1) the self-cleaving RNAs which include the hammerhead, hairpin, hepatitis delta virus, Varkud ,satellite . 2) the self-splicing ribozymes that are the group I and II introns , RNase P.

8. GROUP | INTRON SPLICING Group I intron ribozymes constitute one of the main classes of ribozymes . Found in bacteria, lower eukaryotes and higher plants. Group I introns are also found inserted into genes of a wide variety of bacteriophages of Gram-positive bacteria. However, their distribution in the phage of Gram-negative bacteria is mainly limited to the T4, T-even and T7-like like bacteriophages .

9. Mechanism

10. GROUP | | INTRONS Group II introns have been found in bacteria and in the mitochondrial and chloroplast genomes of fungi, plants, protists , and an annelid worm. Mechanism: The 2’OH of a specific adenosine acts as a nucleophile and attacks the 5’ splice site creating a branched intron structure. The 3’ OH of the 5’ exon attacks the 3’ splice site, ligating the exons and releasing the intron as a lariat structure.

11. Mechanism

12. Rnase P Ribonuclease P ( RNaseP ), a ribonucleoprotein , is an essential tRNA processing enzyme found in all living organisms. Since its discovery almost 40 years ago, research on RNase P has led to the discovery of the catalytic properties of RNA, and of the only known, naturally occurring RNA enzymes.

13. HAMMERHEAD RIBOZYME Hammerhead ribozymes (HHRZs) are tiny autocatalytic RNAs that cleave single-stranded RNA. They are found in nature as a part of certain virus-like elements called virusoids , which use a "rolling-circle replication" mechanism to reproduce their small, circular RNA genomes. The HHRZ is so named because its secondary structure is similarly to that of a hammer head, but actually its tertiary structure is more like ‘Y’ shaped.

14. SPLICEOSOME Spliceosome is a large and complex molecular machine. Which is found in the nucleus of eukaryotic cells. The spliceosome removes introns from a transcribed pre – mRNA. This process known as SPLICING.

15. HAIRPIN RIBOZYME The hairpin ribozyme is an RNA motif that catalyzes RNA processing reactions essential for replication of the satellite RNA molecules in which it is embedded. These reactions are selfprocessing , i.e. a molecule rearranging its own structure. Both cleavage and end joining reactions are mediated by the ribozyme motif.

16. APPLICATION Ribozymes are capable of specially cleaving RNA molecules. Ribozymes are used for to inhibit gene expression. Phase 1 trials using ribozyme gene therapy. Synthetic ribozyme directed against HIV RNA called gene shears.

17. THANKS