What is the significance of DNA Glycosylase in the base excision repair process?

DNA glycosylase plays a crucial role in the base excision repair (BER) process by specifically recognizing and removing damaged or incorrect bases from the DNA. This enzyme scans the DNA for sites of damage, such as those caused by oxidation or deamination, and then cleaves the glycosidic bond between the damaged base and the sugar moiety of the DNA backbone. As a result of this action, the damaged base is excised, leaving behind an apurinic/apyrimidinic site (AP site) in the DNA.

After the removal of the damaged base, other enzymes in the BER pathway take over—DNA polymerase then fills in the gap by adding the correct nucleotide, while DNA ligase seals the final nick in the DNA strand. The action of DNA glycosylase is essential to initiate the repair process and maintain genomic integrity, as the presence of damaged bases can lead to mutations and genomic instability.

By understanding the function of DNA glycosylase within BER, it becomes clear how critical this enzyme is for the preservation of genetic information and in preventing the introduction of mutations that could lead to diseases such as cancer.