PMID: 12592398 , Related PDB ids: 1HU0, 1LWV, 1LWW, 1LWY
Fromme JC, Bruner SD, Yang W, Karplus M, Verdine GL
Product-assisted catalysis in base-excision DNA repair.
Nat Struct Biol. 2003 Mar;10(3):204-11.
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.