Specificity in formation of type II F' plasmids.

AUTOR(ES)

Hadley, R G

RESUMO

Eight new F' plasmids derived from Hfr strains in which F is integrated at the chromosomal element alpha 3 beta 3 have been isolated and subjected to restriction enzyme, hybridization, and electron microscope heteroduplex analysis. Plasmids carrying extensive amounts of bacterial deoxyribonucleic acid were produced even though they were obtained by selection for transfer of lac, which is closely linked to F in the parental Hfr strains. Seven plasmids were type II Flac+ proC+ purE+ plasmids, and one was a type I Flac+ proC+ plasmid. Five of the Flac+ proC+ purE+ plasmids contain approximately 284 kilobases of bacterial deoxyribonucleic acid, which is identical for all five within the resolution of the restriction enzyme analysis. Theses results indicate that type II F' plasmids are the predominant tra+ F' type from this region of the Escherichia coli K-12 chromosome and that the recombination events leading to formation of these plasmids exhibit site specificity.

Documentos Relacionados

• recA-dependent recombination between rRNA operons generates type II F' plasmids.
• Specificity in the formation of delta tra F-prime plasmids.
• dnaB gene of Escherichia coli K-12 affects superinfection inhibition between F' plasmids.
• Heteroduplex analysis of tra delta f' plasmids and the mechanism of their formation.
• RecA-independent recombination at gamma delta termini and at IS3 producing inverted repetition in F' plasmids.