title: Isolation of covalently closed circular deoxyribonucleic acid from bacteria which produce exocellular nuclease.
abstract: Reproducible yields of covalently closed circular (plasmid) deoxyribonucleic acid were obtained from mutants defective for extracellular nuclease but not from the corresponding wild-type strain of Serratia marcescens
mesh_terms: D002247:Carbon Isotopes; D002474:Cell-Free System; D002499:Centrifugation, Density Gradient; D004261:DNA Replication; D004269:DNA, Bacterial / Q000032:analysis / Q000096:biosynthesis / Q000302:isolation & purification*; D004270:DNA, Circular / Q000302:isolation & purification; D004720:Endonucleases / Q000096:biosynthesis* / Q000378:metabolism; D005111:Extrachromosomal Inheritance; D009154:Mutation; D012706:Serratia marcescens / Q000032:analysis* / Q000201:enzymology / Q000378:metabolism; D014316:Tritium
chemical_list: D002247:Carbon Isotopes; D004269:DNA, Bacterial; D004270:DNA, Circular; D014316:Tritium; D004720:Endonucleases