Which one of the following hydrolyses internal phosphodiester bonds in a polynucleotide chain?
Which one of the following hydrolyses internal phosphodiester bonds in a polynucleotide chain?
lipase
protease
endonuclease
exonuclease.
Solution
DNAase (or deoxyribonuclease) or simply nuclease is an enzyme which breaks down DNA by hydrolysis of the phosphodiester bonds of its sugarphosphate back bone. Depending on the position of hydrolyzing phosphodiester bonds, nucleases are of two types: (i) Endonucleases (ii) Exonucleases. Endonucleases hydrolyse internal phosphodiester bonds in a polynucleotide chain (.i.e., DNA). While exonucleases hydrolyse terminal phosphodiester bonds in a polynucleotide chain (.i.e., DNA).