Definition: Translesion synthesis allows the DNA replication machinery to replicate past damaged DNA. This involves the use of specialized translesion DNA polymerases that can insert bases at the site of damage.
Some mechanisms of translesion synthesis introduce mutations, but others do not.
For example, Pol η mediates error-free bypass of lesions induced by UV irradiation, whereas Pol ζ introduces mutations at these sites.
The potential for introducing mutations during translesion synthesis is less dangerous for the cell than continuing the cell cycle with an incompletely replicated chromosome. (WK)
See also
DNA damage
DNA repair