Characterization of the bacillus subtilis bacteriophage PBS-2 induced DNA Polymerase and its associated exonuclease activity
The DNA polymerase induced by Bacillus subtilis bacteriophage PBS2 has a Stokes radius of 5.0 nm and a sedimentation coefficient of 7.2 S in buffers of high ionic strength, suggesting a molecular weight in the range 145,000 to 195,000. The polypeptide bands observed on gel electrophoresis in dodecyl sulfate have apparent molecular weights of 78,000 and 69,000 (and possibly another of 27,000) in equimolar amounts. In buffers of low ionic strength, the enzyme appears to form large aggregates and even precipitates, with about 90% loss of activity. A nuclease activity co-purifies with the PBS2 DNA polymerase and shows similar responses to changes in pH, MgCl/sub 2/, N-ethylmaleimide, temperature, and dextran sulfate levels. The nuclease produces deoxyribonucleoside 5'-monophosphates from denatured DNA containing thymine or uracil. No endonuclease activity is detectable on supercoiled DNA. The inhibition of nuclease activity by added deoxyribonucleoside triphosphates, the DNA-dependent turnover of triphosphates to free monophosphates during DNA polymerization, the inhibition of nuclease activity by 3'-phosphates on the DNA template-primer, and the pattern of digestion of 5'-(/sup 32/P)phosphate-labeled DNA all indicate that the PBS2 DNA polymerase-associated hydrolytic activity is a 3' ..-->.. 5'-exonuclease.
- Research Organization:
- Univ. of Michigan, Ann Arbor
- OSTI ID:
- 6542142
- Journal Information:
- J. Biol. Chem.; (United States), Vol. 253:23
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BACILLUS SUBTILIS
BIOCHEMICAL REACTION KINETICS
BACTERIOPHAGES
DNA
NUCLEASES
METABOLISM
POLYMERASES
CHEMICAL PROPERTIES
ELECTROPHORESIS
MOLECULAR WEIGHT
POLYPEPTIDES
BACILLUS
BACTERIA
ENZYMES
KINETICS
MICROORGANISMS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
PARASITES
PEPTIDES
PHOSPHOTRANSFERASES
PROTEINS
REACTION KINETICS
TRANSFERASES
VIRUSES
550200* - Biochemistry