Abstract
Curing of the mini-ColE1 plasmid pML21 was observed among cells of Escherichia coli K-12 strain C600(pML21) grown under subinhibitory conditions in the presence of trimethoprim, a specific inhibitor of dihydrofolate reductase. Some of the cured colonies showed (i) a reduction in frequency of transformation with pML21 compared with those of isogenic strains not treated with trimethoprim, (ii) loss of viability after acquisition of a recA mutation, and (iii) UV sensitivity greater than that of the original isogenic strain. These colonies therefore had PolA- phenotypes. Moreover, they were found to be deficient in DNA polymerase I activity in the in vitro assays, indicating the occurrence of a polA mutation in them. Many of the colonies with PolA- phenotypes were also thyA deoC mutants, and these mutations, in addition to the polA mutations, appeared to be involved in the expression of the PolA- phenotypes.
Full text
PDF





Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bachmann B. J., Low K. B. Linkage map of Escherichia coli K-12, edition 6. Microbiol Rev. 1980 Mar;44(1):1–56. doi: 10.1128/mr.44.1.1-56.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Berg C. M. Auxotroph accumulation in deoxyribonucleic acid polymeraseless strains of Escherichia coli K-12. J Bacteriol. 1971 Jun;106(3):797–801. doi: 10.1128/jb.106.3.797-801.1971. [DOI] [PMC free article] [PubMed] [Google Scholar]
- CLWES R. C., MOODY E. E., PRITCHARD R. H. THE ELIMINATION OF EXTRACHROMOSOMAL ELEMENTS IN THYMINELESS STRAINS OF ESCHERICHIA COLI K12. Genet Res. 1965 Feb;6:147–152. doi: 10.1017/s0016672300004018. [DOI] [PubMed] [Google Scholar]
- Cohen S. N., Chang A. C., Hsu L. Nonchromosomal antibiotic resistance in bacteria: genetic transformation of Escherichia coli by R-factor DNA. Proc Natl Acad Sci U S A. 1972 Aug;69(8):2110–2114. doi: 10.1073/pnas.69.8.2110. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cohen S. N., Chang A. C. Revised interpretation of the origin of the pSC101 plasmid. J Bacteriol. 1977 Nov;132(2):734–737. doi: 10.1128/jb.132.2.734-737.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cooper P. K., Hanawalt P. C. Role of DNA polymerase I and the rec system in excision-repair in Escherichia coli. Proc Natl Acad Sci U S A. 1972 May;69(5):1156–1160. doi: 10.1073/pnas.69.5.1156. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Csonka L. N., Clark A. J. Construction of an Hfr strain useful for transferring recA mutations between Escherichia coli strains. J Bacteriol. 1980 Jul;143(1):529–530. doi: 10.1128/jb.143.1.529-530.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
- De Lucia P., Cairns J. Isolation of an E. coli strain with a mutation affecting DNA polymerase. Nature. 1969 Dec 20;224(5225):1164–1166. doi: 10.1038/2241164a0. [DOI] [PubMed] [Google Scholar]
- Dubnau E., Maas W. K. Inhibition of replication of an F'lac episome in Hfr cells of Escherichia coli. J Bacteriol. 1968 Feb;95(2):531–539. doi: 10.1128/jb.95.2.531-539.1968. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eberhard C., Herrmann R. L. Effect of deoxyribonucleic acid ligands on deoxyribonucleases and deoxyribonucleic acid polymerase I of Escherichia coli K-12. J Bacteriol. 1972 Oct;112(1):224–230. doi: 10.1128/jb.112.1.224-230.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eichenlaub R., Figurski D., Helinski D. R. Bidirection replication from a unique origin in a mini-F plasmid. Proc Natl Acad Sci U S A. 1977 Mar;74(3):1138–1141. doi: 10.1073/pnas.74.3.1138. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Grindley N. D., Kelley W. S. Effects of different alleles of the E. coli K12 pol A gene on the replication of non-transferring plasmids. Mol Gen Genet. 1976 Feb 2;143(3):311–318. doi: 10.1007/BF00269409. [DOI] [PubMed] [Google Scholar]
- Hershfield V., Boyer H. W., Chow L., Helinski D. R. Characterization of a mini-ColC1 plasmid. J Bacteriol. 1976 Apr;126(1):447–453. doi: 10.1128/jb.126.1.447-453.1976. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kingsbury D. T., Helinski D. R. Temperature-sensitive mutants for the replication of plasmids in Escherichia coli. I. Isolation and specificity of host and plasmid mutations. Genetics. 1973 May;74(1):17–31. doi: 10.1093/genetics/74.1.17. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kingsbury D. T., Helinski D. R. Temperature-sensitive mutants for the replication of plasmids in Escherichia coli: requirement for deoxyribonucleic acid polymerase I in the replication of the plasmid ColE 1 . J Bacteriol. 1973 Jun;114(3):1116–1124. doi: 10.1128/jb.114.3.1116-1124.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kingsbury D. T., Sieckmann D. G., Helinski D. R. Temperature-sensitive mutants for the replication of plasmids in Escherichia coli. II. Properties of host and plasmid mutations. Genetics. 1973 May;74(1):1–16. doi: 10.1093/genetics/74.1.1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kogoma T., Lark K. G. DNA replication in Escherihia coli: replication in absence of protein synthesis after replication inhibition. J Mol Biol. 1970 Sep 14;52(2):143–164. doi: 10.1016/0022-2836(70)90022-7. [DOI] [PubMed] [Google Scholar]
- LENNOX E. S. Transduction of linked genetic characters of the host by bacteriophage P1. Virology. 1955 Jul;1(2):190–206. doi: 10.1016/0042-6822(55)90016-7. [DOI] [PubMed] [Google Scholar]
- Lehman I. R., Chien J. R. Persistence of deoxyribonucleic acid polymerase I and its 5'--3' exonuclease activity in PolA mutants of Escherichia coli K12. J Biol Chem. 1973 Nov 25;248(22):7717–7723. [PubMed] [Google Scholar]
- Lomax M. S., Greenberg G. R. Characteristics of the deo operon: role in thymine utilization and sensitivity to deoxyribonucleosides. J Bacteriol. 1968 Aug;96(2):501–514. doi: 10.1128/jb.96.2.501-514.1968. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Manis J. J., Kline B. C. Restriction endonuclease mapping and mutagenesis of the F sex factor replication region. Mol Gen Genet. 1977 Apr 29;152(3):175–182. doi: 10.1007/BF00268815. [DOI] [PubMed] [Google Scholar]
- Miovic M., Pizer L. I. Effect of trimethoprim on macromolecular synthesis in Escherichia coli. J Bacteriol. 1971 Jun;106(3):856–862. doi: 10.1128/jb.106.3.856-862.1971. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Monk M., Kinross J. Conditional lethality of recA and recB derivatives of a strain of Escherichia coli K-12 with a temperature-sensitive deoxyribonucleic acid polymerase I. J Bacteriol. 1972 Mar;109(3):971–978. doi: 10.1128/jb.109.3.971-978.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mukhopadhyay P., Palchaudhuri S. Trimethoprim-produced F-specific insertion mutations in Escherichia coli K-12. J Bacteriol. 1982 May;150(2):755–761. doi: 10.1128/jb.150.2.755-761.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
- O'Donovan G. A., Neuhard J. Pyrimidine metabolism in microorganisms. Bacteriol Rev. 1970 Sep;34(3):278–343. doi: 10.1128/br.34.3.278-343.1970. [DOI] [PMC free article] [PubMed] [Google Scholar]
- OKADA T., YANAGISAWA K., RYAN F. J. A method for securing thymineless mutants from strains of E. coli. Z Vererbungsl. 1961;92:403–412. doi: 10.1007/BF00890061. [DOI] [PubMed] [Google Scholar]
- Palchaudhuri S., Maas W. K. Fusion of two F-prime factors in Escherichia coli studied by electron microscope heteroduplex analysis. Mol Gen Genet. 1976 Aug 2;146(3):215–231. doi: 10.1007/BF00701244. [DOI] [PubMed] [Google Scholar]
- Smith D. R., Calvo J. M. Nucleotide sequence of dihydrofolate reductase genes from trimethoprim-resistant mutants of Escherichia coli. Evidence that dihydrofolate reductase interacts with another essential gene product. Mol Gen Genet. 1982;187(1):72–78. doi: 10.1007/BF00384386. [DOI] [PubMed] [Google Scholar]
- Timmis K., Cabello F., Cohen S. N. Cloning, isolation, and characterization of replication regions of complex plasmid genomes. Proc Natl Acad Sci U S A. 1975 Jun;72(6):2242–2246. doi: 10.1073/pnas.72.6.2242. [DOI] [PMC free article] [PubMed] [Google Scholar]