title: Replication of plasmid R6K in DNA polymerase deficient mutants of Escherichia coli.
abstract: The plasmid R6K has been introduced into a number of Escherichia coli polymerase deficient (pol) mutants. In polCts mutants transferred to the nonpermissive temperature to inactivate polymerase III, R6K replicates but the replication products have a density in dye-CsCl gradients intermediate between supercoiled and linear forms. This aberrant replication requires normal cellular levels of polymerase I since it does not occur in polA polCts mutants. Normal R6K replication and maintenance occur in a polA polB polC+ host, however, we cannot tell from our experiments wheather polymerase I or III replicates R6K in polA+ polC+ host. Polymerase II, the polB gene product, has no detectable role in R6K replication.
mesh_terms: D004261:DNA Replication; D004269:DNA, Bacterial / Q000096:biosynthesis*; D004270:DNA, Circular / Q000096:biosynthesis*; D004259:DNA-Directed DNA Polymerase / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D011815:R Factors
chemical_list: D004269:DNA, Bacterial; D004270:DNA, Circular; D004259:DNA-Directed DNA Polymerase