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DNA polymerase β is the major dRP lyase involved in repair of oxidative base lesions in DNA by mammalian cell extracts
Author(s) -
Allinson Sarah L.,
Dianova Irina I.,
Dianov Grigory L.
Publication year - 2001
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/20.23.6919
Subject(s) - biology , dna polymerase beta , dna polymerase , dna , microbiology and biotechnology , dna repair , base excision repair , polymerase , oxidative phosphorylation , dna damage , enzyme , biochemistry , lyase
The repair of oxidative base lesions in DNA is a coordinated chain of reactions that includes removal of the damaged base, incision of the phosphodiester backbone at the abasic sugar residue, incorporation of an undamaged nucleotide and sealing of the DNA strand break. Although removal of a damaged base in mammalian cells is initiated primarily by a damage‐specific DNA glycosylase, several lyases and DNA polymerases may contribute to the later stages of repair. DNA polymerase β (Pol β) was implicated recently as the major polymerase involved in repair of oxidative base lesions; however, the identity of the lyase participating in the repair of oxidative lesions is unclear. We studied the mechanism by which mammalian cell extracts process DNA substrates containing a single 8‐oxoguanine or 5,6‐dihydrouracil at a defined position. We find that, when repair synthesis proceeds through a Pol β‐dependent single nucleotide replacement mechanism, the 5′‐deoxyribosephosphate lyase activity of Pol β is essential for repair of both lesions.