PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 6279761

A conjugative 'plasmid' lacking autonomous replication.

M E Nugent
View original source ↗Export metadata ↓

Abstract

Attempts were made to isolate open and covalently closed circular DNA from strains containing the IncJ plasmids. All of the methods tried were unsuccessful. It was shown that the IncJ plasmid R391 can integrate into the Escherichia coli K12 chromosome and can mobilize chromosomal markers from a single origin in an orientated manner. It is proposed that the IncJ plasmids are integrated in the chromosome for most, if not all, of their existence and this explains the inability to isolate plasmid DNA from strains containing them.

Explore related subjects

Conjugation, GeneticDNA ReplicationDNA Transposable ElementsDNA, BacterialDNA, CircularDrug Resistance, MicrobialEscherichia coliProteusR FactorsJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

M E Nugent. 1981. A conjugative 'plasmid' lacking autonomous replication.. https://doi.org/10.1099/00221287-126-2-305

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2024

It's complicated: relationships between integrative and conjugative elements and their bacterial hosts.

Integrative and conjugative elements (ICEs) are typically found integrated in a bacterial host chromosome. They can excise, replicate, and transfer from cell to cell. Many contain genes that confer phenotypes to host cells, including antibiotic resistances, specialized metabolisms, phage defense, and symbiosis or pathogenesis determinants. Recent studies revealed that at least three ICEs (ICEclc, Tn916, and TnSmu1) cause growth arrest or death of host cells upon element activation. This review highlights the complex interactions between ICEs and their hosts, including the recent examples of the significant costs to host cells. We contrast two examples of killing, ICEclc and Tn916, in which killing, respectively, benefits or impairs conjugation and emphasize the importance of understanding the impacts of ICE-host relationships on conjugation. ICEs are typically only active in a small fraction of cells in a population, and we discuss how phenotypes normally occurring in a small subset of host cells can be uncovered.

Conjugation, Genetic↗
PubMed1992

Conjugative trimethoprim resistance in Staphylococcus aureus.

A multiply resistant Staphylococcus aureus isolate, WBG7410, harbours plasmids of 38, 26, 2.8, 2.4 and 1.9 kb and transfers trimethoprim and kanamycin resistance at high frequencies by conjugation. The transconjugants contained the 38-kb plasmid, pWBG707, and the 2.8-kb plasmid. Plasmid pWBG707 was shown to encode trimethoprim resistance, was conjugative and mobilised at high frequencies the 2.8-kb plasmid which presumably encodes kanamycin resistance. Plasmid pWBG707 was isolated mostly in the open circular form and analysis with EcoRI restriction endonuclease suggests that pWBG707 is a new conjugative plasmid distinct from the other conjugative plasmids reported in S. aureus.

Conjugation, Genetic↗
PubMed1992

Molecular monitoring of the transcriptional activation of the yeast Saccharomyces kluyveri mating pheromone signal transduction by using FUS1-lacZ fusion gene.

To analyse the molecular mechanism by which a mating pheromone signal is transmitted in Saccharomyces kluyveri, the S. cerevisiae FUS1-lacZ fusion gene was introduced into S. kluyveri cells and its transcriptional activation was investigated. The expression of FUS1-lacZ fusion product was cell-type-specifically induced by pheromone treatment in S. kluyveri. The result suggests that S. kluyveri pheromone signal may be transduced by a mechanism similar to that in S. cerevisiae. This system may provide a model for analysing the molecular mechanism of the mating reaction in Saccharomyces kluyveri.

Conjugation, Genetic↗