Product-Assisted Catalysis in base-excision DNA RepairFromme, J.C., Bruner, S.D., Yang, W., Karplus, M., Verdine, G.L.
(2003) Nat Struct Biol 10: 204-211
- PubMed: 12592398
- DOI: https://doi.org/10.1038/nsb902
- Primary Citation of Related Structures:
1HU0, 1LWV, 1LWW, 1LWY
- PubMed Abstract:
Most spontaneous damage to bases in DNA is corrected through the action of the base-excision DNA repair pathway. Base excision repair is initiated by DNA glycosylases, lesion-specific enzymes that intercept aberrant bases in DNA and catalyze their excision. How such proteins accomplish the feat of catalyzing no fewer than five sequential reaction steps using a single active site has been unknown. To help answer this, we report the structure of a trapped catalytic intermediate in DNA repair by human 8-oxoguanine DNA glycosylase. This structure and supporting biochemical results reveal that the enzyme sequesters the excised lesion base and exploits it as a cofactor to participate in catalysis. To our knowledge, the present example represents the first documented case of product-assisted catalysis in an enzyme-catalyzed reaction.
Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA.