Restriction Modification Enzymes

This presentation is given by Miss Khunsha Fatima. This presentation will cover mainly Restriction Modification Enzymes, its Types, Applications and its related topics discussed in detail watch the video for more concepts about the topic.

1. Presented By: FATIMAH SINDH BOTECHNOLOGIST ASSOCIATON RESTRICTION - MODIFICATION ENZYMES

2. Restriction Modification Enzymes ? DNA restriction-modification enzymes. They include DNA restriction endonucleases (restriction enzymes) and their companion modification methyl's restriction enzymes, DNA methyltransferases and related proteins, which are generally found together in a multi-protein complex .

3. The  restriction modification system  ( RM system ) is found in bacteria and other prokaryotic organisms, and provides a defense against foreign DNA, such as that borne by bacteriophages.

4. TYPES :- There are four categories of restriction modification systems: type I, type II, type III and type IV.. Type I : The most complex, consisting of three polypeptides: R (restriction), M (modification), and S (specificity). The resulting complex can both cleave and methylate DNA. Type II : The simplest and the most prevalent. Instead of working as a complex, the methyltransferase and endonuclease are encoded as two separate proteins and act independently (there is no specificity protein).

5. Type III : Have R (res) and M (mod) proteins that form a complex of modification and cleavage. The M protein, however, can methylate on its own. Type IV :   Type IV are not true RM systems because they only contain a restriction enzyme and not a methyl's. Unlike the other types, type IV restriction enzymes recognize and cut only modified DNA.

6. USES :- Isolated restriction enzymes are used to manipulate DNA for different scientific applications and are an important tool for recombinant DNA technology. They are used to assist insertion of genes into plasmid vectors during gene cloning and protein production experiments. Restriction enzymes can also be used to distinguish gene alleles by specifically recognizing single base changes in DNA. They are used to digest genomic DNA for gene analysis by southern blot.

7. FUNCTION :- In Genetic Transformation Act as Selfish genetic element Subverting the restriction modification system

8. Applications Molecular biology Cloning : RM systems can be cloned into plasmids and selected because of the resistance provided by the methylation enzyme Restriction Fragment Length Polymorphisms : Restriction enzymes are also used to analyze the composition of DNA Gene therapy The bacteria R-M system has been proposed as a model for devising human anti-viral gene or genomic vaccines and therapies since the RM system serves an innate defense-role in bacteria by restricting tropism of bacteriophages .

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