Micrococcus luteus correndonucleases. I. Resolution and purification of two endonucleases specific for DNA containing pyrimidine dimers. [Uv 500 J/m/sup 2/; x-radiation of 300 Krad; micrococcus lutea]
Five peaks of endonuclease activity showing a preference for ultraviolet-damaged DNA have been chromatographically identified from extracts of Micrococcus luteus. They are numerically designated as I to V in order of their elution from phosphocellulose (Whatman P-11) columns. The first two of these peaks have been highly purified by a combination of gel filtration and affinity chromatography and are catalytically homogeneous judging from their effect on transforming DNAs. Peak I, which has an isoelectric point of 4.7, is heat-stable, requires high ionic strength for optimal activity, acts with equal facility on ultraviolet-irradiated native and denatured DNA, and has been designated as Py--Py correndonuclease I. Peak II which has a pI value of 8.7, is heat-labile, is inhibited by high ionic strength, acts on ultraviolet-irradiated native but not denatured DNA, and has been designated as Py--Py correndonuclease II. Both enzymes are inhibited by Ca/sup 2 +/ and Zn/sup 2 +/, do not show any cofactor or sulfhydryl requirement, act optimally between pH 7.0 and 7.4, and have molecular weights between 11,000 and 15,000. Py--Py correndonuclease I requires a dose about 1.6 times that for Py--Py correndonuclease II for incision saturation of irradiated phiX174 RFI DNA.
- Research Organization:
- Johns Hopkins Univ., Baltimore
- OSTI ID:
- 5112004
- Journal Information:
- J. Biol. Chem.; (United States), Vol. 252:18
- Country of Publication:
- United States
- Language:
- English
Similar Records
Micrococcus luteus correndonucleases. II. Mechanism of action of two endonucleases specific for DNA containing pyrimidine dimers. [Micrococcus lutea; 15 J/m/sup 3/]
Modulation of the DNA scanning activity of the Micrococcus luteus UV endonuclease
Related Subjects
DNA
BIOLOGICAL RADIATION EFFECTS
MICROCOCCUS
ENZYMES
BIOLOGICAL REPAIR
DIMERS
MUTANTS
NUCLEASES
PYRIMIDINES
RADIATION INJURIES
RADIOSENSITIVITY
ULTRAVIOLET RADIATION
X RADIATION
AZINES
BACTERIA
BIOLOGICAL EFFECTS
BIOLOGICAL RECOVERY
ELECTROMAGNETIC RADIATION
HETEROCYCLIC COMPOUNDS
INJURIES
IONIZING RADIATIONS
MICROORGANISMS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOSPHOTRANSFERASES
RADIATION EFFECTS
RADIATIONS
RECOVERY
REPAIR
TRANSFERASES
560131* - Radiation Effects on Microorganisms- Basic Studies- (-1987)