Multiple thymine dimer excising nuclease activities in extracts of human KB cells
Crude extracts of human KB cells grown in suspension culture contain enzyme activity that catalyzes the preferential excision of thymine-containing pyrimidine dimers from uv-irradiated E. coli DNA specifically incised adjacent to dimer sites. Fractionation of KB cell crude extracts reveals the presence of three such activities with distinct affinities for both DEAE-cellulose and phosphocellulose. One of the activities (activity B) is distinguished by its S/sub 20,w/ (2.6) and isoelectric point (9.0) from the other two (activities A and C) which have similar S/sub 20,w/'s (3.0 to 3.2) and isoelectric points (6.0). All three differ in their extent of stimulation by divalent cation and inhibition by NaCl or a sulfhydryl group inhibitor. These results indicate that multiple 5' ..-->.. 3' dimer excision nuclease activities exist in human cells; however, there is as yet no direct evidence that these enzymes are functional in nucleotide excision repair in vivo.
- Research Organization:
- Stanford Univ., CA
- OSTI ID:
- 7090793
- Journal Information:
- Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 17:5; ISSN BICHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
550300 -- Cytology
560111* -- Radiation Effects on Biochemicals-- In Vitro-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
AZINES
BACTERIA
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CATALYSIS
DIMERS
DNA
ELECTROMAGNETIC RADIATION
ENZYMES
ESCHERICHIA COLI
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
IN VITRO
IRRADIATION
MAMMALS
MAN
MICROORGANISMS
NUCLEASES
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOSPHOTRANSFERASES
PRIMATES
PYRIMIDINES
RADIATION EFFECTS
RADIATIONS
RADIOINDUCTION
RECOVERY
REPAIR
THYMINE
TRANSFERASES
ULTRAVIOLET RADIATION
URACILS
VERTEBRATES