Rolling-circle replication of the plasmid pKYM isolated from a gram-negative bacterium.
Plasmid pKYM isolated from a Gram-negative bacterium encodes a Rep protein that is essential for plasmid replication. A comparison of Rep protein from pKYM to Rep proteins encoded by other plasmids shows that it has homology to Rep proteins of the pUB110 plasmid family from Gram-positive bacteria. These plasmids replicate by a rolling-circle mechanism in which a tyrosine residue in the Rep protein acts as the acceptor for the 5' end of the single-strand break introduced by the Rep protein. A Tyr----Phe substitution in the pKYM Rep protein abolishes its activity. Strand-specific single-stranded circular plasmid DNA can be recovered from the cells carrying pKYM and thus we propose that the plasmid pKYM replicates by a rolling-circle mechanism.
Yasukawa
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H
Department of Microbiology, Faculty of Pharmaceutical Sciences, Kanazawa University, Japan.
Hase
T
T
Sakai
A
A
Masamune
Y
Y
D000251:Adenosine Triphosphatases / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D005075:Biological Evolution; D015139:Blotting, Southern; D004265:DNA Helicases; D004261:DNA Replication; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D006090:Gram-Negative Bacteria / Q000235:genetics*; D007700:Kinetics; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009838:Oligodeoxyribonucleotides; D010957:Plasmids; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D014169:Transformation, Bacterial
D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D009838:Oligodeoxyribonucleotides; D011994:Recombinant Proteins; C506744:rep protein, E coli; D000251:Adenosine Triphosphatases; D004265:DNA Helicases