DNA ligase is an essential enzyme responsible for joining Okazaki fragments, the short segments of DNA created on the lagging strand during replication. Without functional ligase, these fragments remain disconnected. This inability to seal nicks in the newly synthesized DNA can lead to an accumulation of single-strand breaks and double-strand breaks in the genome.
The integrity of the genome is paramount for cellular survival and proper function. Breaks in the DNA backbone can trigger cell cycle arrest and apoptosis, programmed cell death. Furthermore, unrepaired breaks increase the risk of mutations and chromosomal abnormalities, potentially contributing to genomic instability and diseases like cancer. The discovery and characterization of DNA ligase have been crucial to understanding DNA replication and repair mechanisms. This knowledge has broad implications for research in genetics, medicine, and biotechnology.
