Structural basis for removal of adenine mispaired with 8-oxoguanine by MutY adenine DNA glycosylaseFromme, J.C., Banerjee, A., Huang, S.J., Verdine, G.L.
(2004) Nature 427: 652-656
- PubMed: 14961129
- DOI: https://doi.org/10.1038/nature02306
- Primary Citation of Related Structures:
1RRQ, 1RRS, 1VRL
- PubMed Abstract:
The genomes of aerobic organisms suffer chronic oxidation of guanine to the genotoxic product 8-oxoguanine (oxoG). Replicative DNA polymerases misread oxoG residues and insert adenine instead of cytosine opposite the oxidized base. Both bases in the resulting A*oxoG mispair are mutagenic lesions, and both must undergo base-specific replacement to restore the original C*G pair. Doing so represents a formidable challenge to the DNA repair machinery, because adenine makes up roughly 25% of the bases in most genomes. The evolutionarily conserved enzyme adenine DNA glycosylase (called MutY in bacteria and hMYH in humans) initiates repair of A*oxoG to C*G by removing the inappropriately paired adenine base from the DNA backbone. A central issue concerning MutY function is the mechanism by which A*oxoG mispairs are targeted among the vast excess of A*T pairs. Here we report the use of disulphide crosslinking to obtain high-resolution crystal structures of MutY-DNA lesion-recognition complexes. These structures reveal the basis for recognizing both lesions in the A*oxoG pair and for catalysing removal of the adenine base.
Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.