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.
Institute of Cytology and Genetics Siberian Branch of the USSR Academy of Sciences, Novosibirsk.
R I
RI
Salganik
G L
GL
Dianov
O A
OA
Medvedev
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