The sequence of DNA bases found within our chromosomes serves as the instruction manual of life. Prior to cell division, this genetic information is accurately copied by a complex of different enzymes known collectively as the replisome. An essential component of this machinery is the DNA polymerase, which acts as the DNA copying enzyme. DNA bases that have been chemically damaged block the progression of the polymerase and can lead to disease causing mutations. Translesion synthesis is one pathway our cells utilize to tolerate DNA damage. This pathway, depicted above in an abstract mixed media collage, utilizes specialized translesion DNA polymerases (red-orange) that can synthesize across from damaged DNA bases. The exchange between the normal replicative DNA polymerase, shown in blue, and the translesion polymerase is controlled by the processivity factor (yellow), a ring shaped molecule which concurrently binds both polymerases and tethers them to their DNA substrates.
Artwork Contributed by Artist Erin Palazzolo Loparo and Joseph Loparo, PhD, Assistant Professor of Biological Chemistry and Molecular Pharmacology, Harvard Medical School.
If you want to learn some details about DNA replication and repair, the links below will direct you to Wikipedia pages with many in-text links that define any unfamiliar terminology:
To read more about the Replisome and DNA replication, click here.
To read more about DNA damage and how the cell deals with it, including translesion synthesis, click here.