Site-specific mutagenesis by a propanodeoxyguanosine adduct carried on an M13 genome.
The spectrum of mutations induced upon in vivo replication of an M13 genome containing a site-specifically located propanodeoxyguanosine (PdG) adduct was determined. PdG was used as a model for the major deoxyguanosine adduct produced on reaction of DNA with the endogenous genotoxin malondialdehyde. PdG was introduced at position 6256 of M13MB102 by ligating the oligodeoxynucleotide 5'-GGT(PdG)TCCG-3' into an 8-base gap in the (-)-strand of duplex M13MB102. Replication of the adducted strand was maximized by incorporation of uracil into the unadducted (+)-strand. Following replication of dG-containing and PdG-containing M13MB102 genomes in Escherichia coli JM105, frameshift mutations were detected as phenotypic changes in the lacZ alpha marker gene. Base pair substitutions were detected by differential hybridization using 32P-labeled 13-mers bearing different bases opposite position 6256. Neither frameshift nor base pair substitution mutations were detected following replication of PdG-adducted genomes in non-SOS-induced JM105. However, PdG-->T transversions and PdG-->A transitions were detected following transformation of PdG-adducted M13MB102 into SOS-induced JM105. Both types of mutations were detected at comparable frequencies, and the total mutation frequency was approximately 2%. The results indicate that PdG is an efficient premutagenic lesion in E. coli strains in which the SOS response is induced.
A. B. Hancock, Jr. Memorial Laboratory for Cancer Research, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146.
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PC
Burcham
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LJ
Marnett
D017104:Bacteriophage M13 / Q000235:genetics*; D001483:Base Sequence; D002460:Cell Line; D018736:DNA Adducts; D004249:DNA Damage; D017931:DNA Primers; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000235:genetics; D016679:Genome, Viral; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009153:Mutagens; D009693:Nucleic Acid Hybridization
D018736:DNA Adducts; D017931:DNA Primers; D009153:Mutagens; C060934:1,N(2)-propanodeoxyguanosine; D003849:Deoxyguanosine