What is the main role of DNA ligase in the DNA repair process?

DNA ligase plays a crucial role in the DNA repair process by catalyzing the formation of phosphodiester bonds between adjacent nucleotides, effectively linking them together. This activity is especially important after DNA polymerase has extended the DNA strand during synthesis or repair, as it ensures that Okazaki fragments on the lagging strand are joined together, thereby restoring the integrity of the DNA molecule.

During DNA repair, breaks in the phosphodiester backbone must be sealed to maintain the stability and continuity of the DNA. DNA ligase recognizes these nicks and facilitates the joining of the strands, which is critical for maintaining the correct structure and function of the DNA. This action also prevents the loss of genetic information and is essential for proper cellular function and replication.

By linking bases after polymerase activity, DNA ligase ensures that the newly synthesized DNA is complete and intact, enabling the cell to proceed with its normal processes without encountering errors that could lead to mutations or instability.