RESTRICTION ENZYMES

RESTRICTION ENZYMES

Restriction enzymes are help in cutting of DNA into smaller fragments. Different restriction enzymes acknowledge and cut different DNA sequences. Restriction enzymes are also known as molecular scissor. 

WHERE DO RESTRICTION ENZYMES COME FROM? 

Restriction enzymes are found in bacteria. Bacteria use restriction enzymes to kill viruses the enzyme attack the viral DNA and break it into useless fragments. 

HOW DO RESTRICTION ENZYMES WORK? 

Restriction enzymes works by shape matching, when it comes into contact with DNA sequences with a shape, that matches a part of the enzyme, called DNA sequences, it wraps around the DNA and causes a break in both strands of the DNA molecule. 

Each restriction enzymes recognises a different and specific recognition site,  or DNA sequences. Recognition sites are usually only short 4-8 nucleotides.

WHEN ARE RESTRICTION ENZYMES ARE USED? 

Restriction enzymes are a basic tool for biotechnological research. They are used for DNA fingerprinting and DNA cloning.

TYPES OF RESTRICTION ENZYMES? 

There are three different kinds of restriction enzymes. 

• Exonucleases

• Endonucleases

• Restriction endonucleases

RESTRICTION EXONUCLEASES

Restriction exonucleases are primarily responsible for hydrolysis of the terminal nucleotide from the end of DNA or RNA molecule either from 5' to 3' direction or 3' to 5' direction for example- Exonucleases 1 and Exonucleases 2.

ENDONUCLEASES

This enzyme cleaves the double stranded DNA at a any point except the ends.

RESTRICTION ENDONUCLEASES

These enzymes are formed naturally in bacteria. They cut both strands of DNA duplex.