The thymine-thymine pyrimidine-pyrimidone(6-4) ultraviolet light photoproduct is highly mutagenic and specifically induces 3 prime thymine-to-cytosine transitions in Escherichia coli

Journal Article · Fri Nov 01 00:00:00 EST 1991 · Proceedings of the National Academy of Sciences of the United States of America; (United States)

DOI:https://doi.org/10.1073/pnas.88.21.9685· OSTI ID:5821428

LeClerc, J E; Borden, A; Lawrence, C W ^[1]

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1. Univ. of Rochester, NY (United States)

The authors have constructed single-stranded, M13-based vectors that contain a specifically located thymine-thymine pyrimidine-pyrimidone(6-4) UV photoproduct and have used these to estimate the frequency and accuracy of DNA replication past this adduct in uvrA6 cells of Escherichia coli. Both the normal and the Dewar valence photoisomer of the (6-4) adduct were studied. In the absence of SOS induction, vectors carrying the photoproducts were rarely replicated; relative to the lesion-free control, 1.9% of vectors carrying the normal (6-4) isomer produced plaques, and with the Dewar valence isomer the proportion was 0.4%. In SOS-induced cells, these frequencies rose to 22.1% and 12.3%, respectively. The error frequency of replication past the normal isomer in SOS-induced cells was high. They speculate that the high error frequency and specificity arise from the formation of a stable T{center dot}G base pair, involving hydrogen bonds at O-2 and N-3 in the pyrimidone ring. Potential hydrogen bonds at these sites are coplanar in the normal but not in the Dewar isomer, perhaps explaining the reduced specificity of mutagenesis with the latter adduct.

• DOE Contract Number: FG02-88ER60626
• OSTI ID: 5821428
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (United States), Vol. 88:21; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
DNA REPAIR
MOLECULAR BIOLOGY
DNA REPLICATION
BIOLOGICAL RADIATION EFFECTS
PYRIMIDINE DIMERS
RADIOINDUCTION
DNA BASE TRANSITIONS
ESCHERICHIA COLI
EXTREME ULTRAVIOLET RADIATION
LIQUID COLUMN CHROMATOGRAPHY
MUTAGENESIS
PHOTOPRODUCTION
THYMINE
AZINES
BACTERIA
BASIC INTERACTIONS
BIOLOGICAL EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CHROMATOGRAPHY
ELECTROMAGNETIC INTERACTIONS
ELECTROMAGNETIC RADIATION
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
INTERACTIONS
MICROORGANISMS
NUCLEIC ACID REPLICATION
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PARTICLE INTERACTIONS
PARTICLE PRODUCTION
PYRIMIDINES
RADIATION EFFECTS
RADIATIONS
RECOVERY
REPAIR
SEPARATION PROCESSES
ULTRAVIOLET RADIATION
URACILS
550201* - Biochemistry- Tracer Techniques