Amplification in Escherichia coli of enzymes involved in genetic recombination: construction of hybrid ColE1 plasmids carrying the structural gene for exonuclease I.
AUTOR(ES)
Vapnek, D
RESUMO
Endo-R-HindIII restriction endonuclease fragments obtained from F30 and pMB9 plasmid DNAs were ligated in vitro and used to transform a recB21 recC22 sbcB15 strain of E. coli K-12. The inability of this strain to stably maintain pMB9 alone permitted the isolation of transformants that carried hybrid plasmids containing the sbcB+ allele. These transformants became sensitive to ultraviolet light and recombination defieient and showed a 25-fold increase in the level of exonuclease I activity. The stability of the sbcB hybrid plasmids and their effects on exonuclease I activity have also been determined in wild-type and recA1 genetic backgrounds. The presence of the plasmids results in a 7-fold increase in the level of exonuclease I in a wild-type strain and 15-fold increase in a recA1 strain. The increased activity in the recA1 mutant appears to be a result of increased plasmid stability in this genetic background.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=431142Documentos Relacionados
- ColE1 hybrid plasmids for Escherichia coli genes of glycolysis and the hexose monophosphate shunt.
- Synthesis of mot and che gene products of Escherichia coli programmed by hybrid ColE1 plasmids in minicells.
- Biochemical construction of specific chimeric plasmids from ColE1 DNA and unfractionated Escherichia coli DNA.
- Homology between Escherichia coli plasmids ColE1 and p15A.
- Alternative forms of lethality in mitomycin C-induced bacteria carrying ColE1 plasmids