Evidence for lack of DNA photoreactivating enzyme in humans

Journal Article · Sat May 15 00:00:00 EDT 1993 · Proceedings of the National Academy of Sciences of the United States of America; (United States)

OSTI ID:6030187

Li, Ywan Feng; Kim, Sang-Tae; Sancar, A ^[1]

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1. 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), Vol. 90:10; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
DNA-ASE
PHOTOREACTIVATION
HUMAN POPULATIONS
BIOLOGICAL RADIATION EFFECTS
BLOOD CELLS
DNA
ESCHERICHIA COLI
HELA CELLS
SNAKES
ULTRAVIOLET RADIATION
YEASTS
ANIMALS
BACTERIA
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
BLOOD
BODY FLUIDS
ELECTROMAGNETIC RADIATION
ENZYMES
ESTERASES
EUMYCOTA
FUNGI
HYDROLASES
MATERIALS
MICROORGANISMS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
PHOSPHODIESTERASES
PLANTS
POPULATIONS
PROTEINS
RADIATION EFFECTS
RADIATIONS
REPAIR
REPTILES
VERTEBRATES
550200* - Biochemistry
560120 - Radiation Effects on Biochemicals
Cells
& Tissue Culture