Effect of 17 beta-estradiol-DNA adducts on the replication of exon # 5 of the human suppressor gene p53

Using a PCR technique, exon # 5 of the human tumor suppressor gene p53 was amplified and ligated into the pCRII vector and transformed into Escherichi a coli INV alpha F' competent cells. The cloned exon # 5 was 184 bp long. E vidence is presented to show that after dimethyldioxirane epoxidation, 17 b eta-estradiol was able to form 17 beta-estradiol-DNA adducts and to strongl y inhibit the replication of the cloned exon # 5 producing smaller sizes of DNA fragments and introducing errors of incorporation at the 3'-end of the terminating DNAs, The errors occurred mainly at the clusters of the comple mentary 'G' and 'A' bases on the template strand DNA, presumably, the major sites where the 17 beta-estradiol-DNA adducts were formed. (C) 1999 Federa tion of European Biochemical Societies.