Restriction Endonucleases

1. Enzymes used in Recombinant DNA technology

The gene expression studies advanced during 1970s and 1980s and were based on the developments in recombinant DNA technology. The concept of recombinant DNA technology is based on the manipulation of DNA in test tubes. This manipulation depends on the specific enzymes called restriction endonucleases. The working of these enzymes is known and can be controlled to modify the DNA. All the enzymes that are used in recombinant DNA technology can be grouped in the following categories:

1.      DNA polymerases: These enzymes help in the synthesis of a new DNA strand on a DNA or RNA template.

2.      Nucleases: these enzymes degrade the DNA molecules by breaking the phosphodiester bond between two nucleotides in a polynucleotide.

3.      Ligases: These enzymes join the two DNA molecules by forming phosphodiester bond between them.

4.     End-modification enzymes: These enzymes modify the ends of the DNA molecules and help in the manipulation of DNA.