title: Isolation and characterization of lambda transducing bacteriophages for the su1+ (supD minus) amber suppressor of Escherichia coli.
abstract: Specialized lambda transducing phages for the sul+ (supD-) amber suppressor in Escherichia coli K-12 have been isolated, using a secondary site lambda-cI857 lysogen in which we have shown the prophage to be closely linked to sul+.sul+ transducing particles were detected frequently, at 10-5 per plaque-forming unit, in lysates prepared from the secondary-site lysogens. High-frequency transducing lysates were obtained from several independently isolated sul+ transductants and were analyzed by CsCl equilibrium density gradient centrifugation. The transducing phages are defective; marker rescue analysis indicates that the lambda-N gene is not present. In lambda-cI857DELTANdSul+, a bio-type transducing phage, the genes specifying recombination and excision functions have been replaced by bacterial deoxyribonucleic acid.
mesh_terms: D002499:Centrifugation, Density Gradient; D002848:Chromatography, DEAE-Cellulose; D002874:Chromosome Mapping; D003090:Coliphages / Q000254:growth & development / Q000302:isolation & purification; D004267:DNA Viruses; D003673:Defective Viruses / Q000254:growth & development; D004926:Escherichia coli / Q000378:metabolism*; D008040:Genetic Linkage; D009153:Mutagens; D009154:Mutation; D009604:Nitrosoguanidines; D012328:RNA Viruses; D012329:RNA, Bacterial; D012343:RNA, Transfer; D011995:Recombination, Genetic; D013489:Suppression, Genetic; D013941:Thymine; D014161:Transduction, Genetic
chemical_list: D009153:Mutagens; D009604:Nitrosoguanidines; D012329:RNA, Bacterial; D012343:RNA, Transfer; D013941:Thymine