Site and strand specificity of UVB mutagenesis in the SUP4-o gene of yeast

Journal Article · Thu Nov 01 00:00:00 EST 1990 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.87.22.9005· OSTI ID:6320757

Armstrong, J D; Kunz, B A ^[1]

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1. Univ. of Manitoba, Winnipeg (Canada)

DNA sequencing was used to characterize 208 mutations induced in the SUP4-o tRNA gene of the yeast Saccharomyces cerevisiae by UVB (285-320 nm) radiation. The results were compared to those for an analysis of 211 SUP4-o mutations induced by 254-nm UVC light. In each case, greater than 90% of the mutations were single base-pair changes but G.C----A.T transitions predominated and accounted for more of the mutations induced by UVB than UVC. Double substitutions, single base-pair deletions, and more complex events were also recovered. However, UVB induced 3-fold more tandem substitutions than UVC and nontandem double events were detected only after irradiation with UVC. Virtually all induced substitutions occurred at sites where the pyrimidine of the base pair was part of a dipyrimidine sequence. Although the site specificities were consistent with roles for cyclobutane dimers and pyrimidine-pyrimidone(6-4) lesions in mutation induction, preliminary photoreactivation data implicated cyclobutane dimers as the major form of premutational DNA damage for both agents. Intriguingly, there was a preference for both UVB- and UVC-induced mutations to occur at sites where the dipyrimidine was on the transcribed strand.

• OSTI ID: 6320757
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (USA), Vol. 87:22; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
GENE MUTATIONS
RADIOINDUCTION
SACCHAROMYCES CEREVISIAE
GENETIC RADIATION EFFECTS
TRANSFER RNA
GENES
ULTRAVIOLET RADIATION
MUTAGENESIS
DNA REPAIR
DNA SEQUENCING
PYRIMIDINE DIMERS
TRANSCRIPTION
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
ELECTROMAGNETIC RADIATION
EUMYCOTA
FUNGI
GENETIC EFFECTS
MICROORGANISMS
MUTATIONS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
PLANTS
RADIATION EFFECTS
RADIATIONS
RECOVERY
REPAIR
RNA
SACCHAROMYCES
STRUCTURAL CHEMICAL ANALYSIS
YEASTS
560130* - Radiation Effects on Microorganisms