Cluster of point mutations predetermined by a quasipalindromic nucleotide sequence in plasmid pBR322 DNA.
Development of a cluster of point mutations due to the correction of an imperfect hairpin in plasmid DNA was investigated. Plasmid pBR322 DNA containing opposite double-strand DNA lesions in the region of a quasipalindrome was constructed. For this aim plasmid DNA was cleaved at the BamHI site, and cytosine residues of the sticky ends were modified by O-methylhydroxylamine. Modified linearized plasmid DNA was ligated and used for transformation of E.coli cells. Tetracycline-sensitive transformants were selected, and the mutants were characterized by restriction and sequencing analysis. One mutant contained a cluster of point mutations. The distribution of mutations was consistent with the cluster having arisen through correction of the imperfect hairpin formed by the quasipalindrome.
Salganik
R I
RI
Institute of Cytology and Genetics Siberian Branch of the USSR Academy of Sciences, Novosibirsk.
Dianov
G L
GL
Medvedev
O A
OA
D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics*; D015245:Deoxyribonuclease BamHI; D015252:Deoxyribonucleases, Type II Site-Specific; D004926:Escherichia coli / Q000235:genetics; D006898:Hydroxylamines; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation; D010957:Plasmids; D012091:Repetitive Sequences, Nucleic Acid; D014169:Transformation, Bacterial
D004269:DNA, Bacterial; D006898:Hydroxylamines; C005214:methoxyamine; D015245:Deoxyribonuclease BamHI; D015252:Deoxyribonucleases, Type II Site-Specific; C024403:GGCC-specific type II deoxyribonucleases