title: Isolation and characterization of replication-deficient mutants of ColE1 plasmids.
abstract: Replication-defective mutants of plasmid ColE1 were isolated from a chimeric plasmid formed by ligating a temperature-sensitive replication derivative of pSC101, pHSG1, with a ColE1-Tn3-containing plasmid. The replication-defective ColE1 mutants isolated were all spontaneous deletion mutants that had lost the ColE1 replication origin and regions adjacent to it. The extent of a deletion was determined by analyzing restriction endonuclease-generated deoxyribonucleic acid fragments of the ColE1 plasmid component of the chimeras by both agarose and polyacrylamide gel electrophoresis. None of the chimeras containing the replication-defective ColE1 mutants was able to replicate in the presence of chloramphenicol. The expression of ColE1 incompatibility was either markedly reduced or not detectable in the replication mutants isolated.
mesh_terms: D002701:Chloramphenicol / Q000494:pharmacology; D004261:DNA Replication / Q000187:drug effects; D004269:DNA, Bacterial / Q000235:genetics*; D004274:DNA, Recombinant; D004926:Escherichia coli / Q000235:genetics*; D005796:Genes; D009154:Mutation; D010957:Plasmids; D013696:Temperature
chemical_list: D004269:DNA, Bacterial; D004274:DNA, Recombinant; D002701:Chloramphenicol