Evidence for lack of DNA photoreactivating enzyme in humans
- Univ. of North Carolina, Chapel Hill (United States)
Photoreactivating enzyme (DNA photolyase; deoxyribocyclobutadipyrimidine pyrimidine-lyase, EC 4.1.99.3) repairs uv damage to DNA by utilizing the energy of near-uv/visible light to split pyrimidine dimers into monomers. The enzyme is widespread in nature but is absent in certain species in a seemingly unpredictable manner. Its presence in humans has been a source of considerable controversy. To help resolve the issue the authors used a very specific and sensitive assay to compare photoreactivation activity in human, rattlesnake, yeast, and Escherichia coli cells. Photolyase was easily detectable in E. coli, yeast, and rattlesnake cell-free extracts but none was detected in cell-free extracts from HeLa cells or human white blood cells with an assay capable of detecting 10 molecules per cell. They conclude that humans most likely do not have DNA photolyase. 45 refs., 4 figs., 1 tab.
- OSTI ID:
- 6030187
- Journal Information:
- Proceedings of the National Academy of Sciences of the United States of America; (United States), Journal Name: Proceedings of the National Academy of Sciences of the United States of America; (United States) Vol. 90:10; ISSN PNASA6; ISSN 0027-8424
- Country of Publication:
- United States
- Language:
- English
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560120 -- Radiation Effects on Biochemicals
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59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BACTERIA
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
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BLOOD CELLS
BODY FLUIDS
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DNA-ASE
ELECTROMAGNETIC RADIATION
ENZYMES
ESCHERICHIA COLI
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EUMYCOTA
FUNGI
HELA CELLS
HUMAN POPULATIONS
HYDROLASES
MATERIALS
MICROORGANISMS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
PHOSPHODIESTERASES
PHOTOREACTIVATION
PLANTS
POPULATIONS
PROTEINS
RADIATION EFFECTS
RADIATIONS
REPAIR
REPTILES
SNAKES
ULTRAVIOLET RADIATION
VERTEBRATES
YEASTS