title: Damage and mutagenesis of E. coli and bacteriophage lambda induced by oxathiolane and aziridinyl steroids.
abstract: lambda-Escherichia coli complexes exhibited remarkable sensitivity to the treatment with test steroidal derivatives in the presence of Cu(II). The decline in plaque-forming units after steroid treatment was more pronounced in complexes with some of the radiation repair-defective mutants of E. coli K-12, i.e., recA, lexA and polA, as compared to uvrA and wild-type strains. The red gene of lambda phage and recA gene of E. coli seem to have a complementary effect on the steroid-induced lesions. An enhanced level of mutagenesis was observed when steroid-treated E. coli cells were transformed with steroid-treated pBR322 plasmid DNA. A remarkable degree of c mutation was also observed when steroid I-treated phage particles were allowed to adsorb on steroid-treated wild-type bacteria. Moreover, the oxathiolane steroid treatment of lambda cI857-E. coli lysogen resulted in prophage induction in nutrient broth even at 32 degrees C. Thus on the basis of these results, the role of SOS repair system in steroid-induced mutagenesis and repair of DNA lesions in E. coli and bacteriophage lambda has been suggested.
authors.affiliation: Department of Biochemistry, A.M.U., Aligarh, India.
authors.forename: S A
authors.initials: SA
authors.lastname: Qadri
authors.forename: M
authors.initials: M
authors.lastname: Ahmad
mesh_terms: D001388:Aziridines / Q000633:toxicity; D010582:Bacteriophage lambda / Q000187:drug effects* / Q000235:genetics; D002776:Cholestanes / Q000633:toxicity; D002777:Cholestanols / Q000633:toxicity; D004249:DNA Damage; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics; D016166:Free Radical Scavengers / Q000378:metabolism; D016296:Mutagenesis; D009153:Mutagens / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013014:SOS Response, Genetics; D013256:Steroids / Q000633:toxicity*; D013871:Thiones / Q000633:toxicity; D014775:Virus Activation
chemical_list: D001388:Aziridines; D002776:Cholestanes; D002777:Cholestanols; D016166:Free Radical Scavengers; D009153:Mutagens; D017382:Reactive Oxygen Species; D013256:Steroids; D013871:Thiones; C071679:3-acetoxycholestanol(5,6-b)(N-phthalimido)aziridine; C081097:3-acetoxy-5-cholestano(6,5-d')-1',3'-oxathiolane-2'-thione