POLI is an error-prone DNA polymerase specifically involved in DNA repair.POLI plays an important role in translesion synthesis, where the normal high-fidelity DNA polymerases cannot proceed and DNA synthesis stalls.POLI favors Hoogsteen base-pairing in the active site.POLI inserts the correct base with high-fidelity opposite an adenosine template.POLI exhibits low fidelity and efficiency opposite a thymidine template, where it will preferentially insert guanosine.POLI may play a role in hypermutation of immunogobulin genes.POLI forms a Schiff base with 5'-deoxyribose phosphate at abasic sites, but may not have lyase activity.