Nukleázokat

Nukleázokat are enzymes that cleave nucleic acids, which are polymers of nucleotides. Nucleic acids exist in two main forms: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Nukleázokat can be classified based on their substrate specificity and the type of bond they cleave.

By substrate specificity, nukleázokat are divided into deoxyribonucleases (DNases) that act on DNA and ribonucleases (RNases) that act on RNA. Some nukleázokat are specific for single-stranded nucleic acids, while others prefer double-stranded forms.

By the type of bond cleaved and the resulting products, nukleázokat are further categorized. Exonucleases sequentially remove nucleotides from the ends of a nucleic acid strand. They can act from the 5' end or the 3' end. Endonucleases cleave phosphodiester bonds within a nucleic acid strand, creating internal breaks. These enzymes are crucial for DNA repair, replication, and recombination processes. For example, restriction endonucleases are enzymes that cut DNA at specific recognition sequences, a vital tool in molecular biology for DNA manipulation. RNases play roles in RNA processing, degradation, and gene silencing.

The activity of nukleázokat is influenced by factors such as pH, temperature, and the presence of metal ions, which often act as cofactors. These enzymes are essential for many biological processes and are widely used in biotechnology and research.