DDB1 Proteins and Enzymes

Damage specific DNA binding protein (DDB) functions in nucleotide-excision repair. Its defective activity causes the repair defect in the patients with xeroderma pigmentosum complementation group E (XPE). To test whether the DNA-repair defect in the subset of XPE patients that lack DNA damage-binding activity is caused by a defect in DDB, purified human DDB protein was injected into XPE cells. The injected DDB protein stimulated DNA repair to normal levels in those strains that lacked the DDB ...