Lõhutusensüümid

Lõhutusensüümid, more commonly known as restriction enzymes or restriction endonucleases, are a class of enzymes that cleave DNA molecules at specific recognition nucleotide sequences known as restriction sites. These enzymes are naturally occurring in bacteria and archaea, where they function as a defense mechanism against invading viruses by degrading foreign DNA.

Restriction enzymes are essential tools in molecular biology and genetic engineering. They are widely used in recombinant DNA technology to cut DNA into manageable fragments, which can then be ligated into vectors for cloning or analysis. The specificity of restriction enzymes allows for precise manipulation of DNA, enabling scientists to isolate genes, construct recombinant DNA molecules, and study DNA structure and function.

The discovery of restriction enzymes in the 1970s revolutionized molecular biology. It led to the development of techniques such as gene cloning, DNA sequencing, and restriction fragment length polymorphism (RFLP) analysis. These advancements have been instrumental in understanding gene function, diagnosing genetic diseases, and developing genetically modified organisms.

Restriction enzymes are classified into different types based on their structure, mode of action, and the nature of their restriction site and cleavage pattern. Type II restriction enzymes, which recognize palindromic sequences and cut within or adjacent to their recognition sites, are the most commonly used in molecular biology applications. The ability to cut DNA at specific locations has made restriction enzymes indispensable for a vast array of molecular biology techniques.