Abstract
The 23 S twisted circular form of Col E 1 DNA has been isolated from Escherichia coli as a tightly associated DNA-protein complex with a sedimentation coefficient of approximately 24 S . Treatment of this complex with pronase, trypsin, sodium dodecyl sulfate, Sarkosyl, or heat results in a conversion to a slower sedimenting form of 17 S or 18 S , as determined by centrifugation in neutral sucrose gradients. These treatments do not alter the sedimentation properties of noncomplexes supercoiled Col E 1 DNA even in the presence of the Col E 1 -protein complex. Electron microscopic analyses indicate that the decrease in sedimentation rate of the Col E 1 -protein complex after treatment with these various agents is largely owing to an induced transition of Col E 1 DNA from the supercoiled to the open circular state.
Keywords
Sedimentation coefficientDNA supercoilDNACentrifugationSodium dodecyl sulfateEscherichia coliSedimentationBiologyPronaseBiophysicsTrypsinBiochemistryMolecular biologyChemistryDNA replicationEnzymeGene
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Publication Info
- Year
- 1969
- Type
- article
- Volume
- 62
- Issue
- 4
- Pages
- 1159-1166
- Citations
- 1818
- Access
- Closed
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Cite This
Don B. Clewell,
Donald R. Helinski
(1969).
SUPERCOILED CIRCULAR DNA-PROTEIN COMPLEX IN <i>Escherichia coli</i> : PURIFICATION AND INDUCED CONVERSION TO AN OPEN CIRCULAR DNA FORM.
Proceedings of the National Academy of Sciences
, 62
(4)
, 1159-1166.
https://doi.org/10.1073/pnas.62.4.1159
Identifiers
- DOI
- 10.1073/pnas.62.4.1159