Characterization of an endonuclease associated with the drug resistance plasmid pKM101
An endonuclease was detected in strains of Salmonella typhimurium containing the drug resistance plasmid of pKM101. The enzyme was not detectable in strains lacking this plasmid, but it was present in strains containing mutants of pKM101 that were no longer able to enhance host cell mutagenesis. The endonuclease had a molecular weight of roughly 75,000 and, at pH 7.0, was equally active on single-stranded and duplex deoxyribonucleic acid (DNA). The reaction with single-stranded DNA was optimal at pH 5.5, whereas with duplex DNA the optimum was pH 6.8. The enzyme required a divalent cation for activity, and it had no detectable exonuclease activity with single-stranded or duplex DNA. The endonuclease extensively degraded DNA with no apparent base specificity, forming 5'-phosphomonoester termini. Although characterization of the endonuclease has not revealed its function, the enzyme does not appear to be a restriction endonuclease.
- Research Organization:
- Univ. of California, Berkeley
- DOE Contract Number:
- E(04-3)-34
- OSTI ID:
- 5127404
- Journal Information:
- J. Bacteriol.; (United States), Journal Name: J. Bacteriol.; (United States) Vol. 131:2; ISSN JOBAA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
550700 -- Microbiology
59 BASIC BIOLOGICAL SCIENCES
BACTERIA
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CELL CONSTITUENTS
DNA
ENZYME ACTIVITY
ENZYMES
KINETICS
MICROORGANISMS
MOLECULAR WEIGHT
MUTAGENESIS
MUTATIONS
NUCLEASES
NUCLEIC ACIDS
ORGANIC COMPOUNDS
PH VALUE
PHOSPHOTRANSFERASES
PLASMIDS
REACTION KINETICS
RECOVERY
REPAIR
SALMONELLA
SALMONELLA TYPHIMURIUM
TRANSFERASES