title: Identification and physical characterization of a Col E1 hybrid plasmid containing a catalase gene of Escherichia coli.
abstract: A hybrid Escherichia coli: Col E1 plasmid, pLC36-19, containing a catalase gene has been identified in the Clarke and Carbon colony bank. Catalase activity was amplified two- to three-fold in the pLC36-19-containing strain relative to other hybrid-plasmid-containing strains and this activity could be induced three- or four-fold by hydrogen peroxide or ascorbic acid. The plasmid was transferred to a strain chromosomally deficient in catalase synthesis, resulting in a strain with high and inducible levels of catalase. The plasmid was also transferred to a minicell-producing strain and minicells harbouring the plasmid were found to synthesize a labelled protein with a molecular weight of 84 000 characteristic of catalase from E. coli. A catalase activity was also synthesized by the plasmid-containing minicells. Two catalase activities with associated peroxidase activities coded for by the plasmid were separable by polyacrylamide gel electrophoresis and migrated coincident with chromosomally encoded catalase-peroxidase activities. A third catalase activity which did not have an associated peroxidase activity was not coded for by the plasmid. A physical map of the 25.5-kilobase pair plasmid was constructed by restriction nuclease analysis and the relative positions of 38 restriction sites were defined.
mesh_terms: D003086:Bacteriocin Plasmids; D001483:Base Sequence; D002374:Catalase / Q000235:genetics* / Q000302:isolation & purification; D004262:DNA Restriction Enzymes; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005784:Gene Amplification; D005796:Genes; D005798:Genes, Bacterial; D008970:Molecular Weight; D010957:Plasmids; D013045:Species Specificity
chemical_list: D002374:Catalase; D004262:DNA Restriction Enzymes