The isolation and characteristics of plasmids derived from the insertion of MupAp1 into pML2: Their behavior during transposition

Maynard-Smith, Sheila; Leach, David R. F.; Coelho, Ana; Carey, J.E.; Symonds, N.

doi:10.1016/0147-619x(80)90081-5

Cited by 13 publications

(3 citation statements)

References 19 publications

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“…2), which are still competent for intracellular transposition and growth as a phage when complemented by a wild-type Mu phage. Most of the DNA sequences on these phage have been determined previously (3,7,33,34,46,49 (40) have presented only three insertions, two of which have deletions of plasmid sequences near the insertions, and the other one (38) does not characterize the insertions. lac gene fusions formed by Mu-lac transposition can be genetically unstable in the presence of the Mu transposition or A (lac Mu) (13,36).…”

Section: Discussionmentioning

confidence: 99%

“…Insertions of these elements are stabie in ColElderived plasmids, in contrast to some but not all reports for full-length Mu insertions. Inselburg(32) and others (as discussed in reference 50) have reported the failure to obtain Mu insertions in ColEl-derived plasmids, whereas Maynard-Smith et al(40) and Liebart et al(38) have reported the isolation of such insertions with Mu c+ and Mu cts. The first of the positive reports…”

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confidence: 99%

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Plasmid insertion mutagenesis and lac gene fusion with mini-mu bacteriophage transposons

Castilho¹,

Olfson²,

Casadaban³

1984

J Bacteriol

537

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Small bacteriophage Mu transposable elements containing the lac operon structural genes were constructed to facilitate the isolation and use of Mu insertions and lac gene fusions. These mini-Mu elements have selectable genes for either ampicillin or kanamycin resistance and can be used to form both transcriptional and translational lac gene fusions. Some of the mini-Mu-lac elements constructed are deleted for the Mu A and B transposition genes and form stable insertions that cannot undergo transposition unless complemented for these functions. A procedure was developed for selecting mini-Mu insertions specifically into plasmids, including commonly used high-copy-number cloning vectors such as pBR322. Mu itisertions in pBR322 were found to be distributed around the plasmid, but insertions in certain regions occurred more frequently than in others.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Plasmid insertion mutagenesis and lac gene fusion with mini-mu bacteriophage transposons

Castilho¹,

Olfson²,

Casadaban³

1984

J Bacteriol

537

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“…A molecular size of 96 kb could be expected for pULG3 with a single precise insertion of D108-1. The heterogeneity in the size of the pULG3 : :D108-1 plasmids is not surprising, however, since it was previously reported that transposition of Mu from one replicon to another may result in rearrangements (insertion or deletion) of the recipient replicon (Chaconas et af., 1981;Coelbo et af., 1980;Maynard-Smith et al, 1980). The transposition of D108-1 to random locations in pULG3, as well as the rearrangements induced by the mini-phage , could be related to the differences in transfer frequency of the various pULG3 : :D108-1 plasmids.…”

Section: Plasmid Content Of the E Coli Cmr Transconjugantsmentioning

confidence: 99%

Erwinia uredovora 20D3 Contains an IncM Plasmid

Thiry¹,

Faelen²

1984

Microbiology

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Erwinia uredovora was lysogenized with phages Mucts62 and D108-1, a mini derivative of D108cts10 carrying a Cmr marker. The 20D3(Mucts62)(D108-1) lysogen was induced and used as donor in a mating with a phage-resistant Escherichia coli; the Cmr marker was transferred to this recipient strain at low frequency. The analysis of the Cmr transconjugants indicated that they had acquired the pULG3 plasmid of E. uredovora associated with a D108-1 prophage. Subsequent transfer of these pULG3 derivatives within E. coli indicated that pULG3 was conjugative. Incompatibility experiments showed that pULG3 is a member of the IncM group. I N T R O D U C T I O NErwinia uredovora belongs to the herbicola group of the genus Erwinia. These are yellow pigmented enterobacteriaceae, often isolated as epiphytes. The peculiarity of the uredovora species resides in their ability to destroy the uredia and urediospores of the rust fungus Puccinia (Buchanan & Gibbons, 1974).Recent work shows that E. uredovora 20D3 : (i) produces a phage tail-like bacteriocin active against the phytopathogenic strains Erwinia carotovora and Erwinia amylovora (Thiry-Braipson et al., 1982); (ii) contains three plasmids with molecular sizes of 260 kb (pULGl), 216 kb (pULG2) and 88 kb (pULG3), with pULG1 involved in both yellow pigmented and thiaminindependent phenotypes (Thiry, 1984); and (iii) adsorbs and propagates the phages Mu and D108 (Faelen et al., 1981). Mu and D108 are mutator phages that are heteroimmune and closely related. The analysis of heteroduplexes between the DNA of the two phages indicates an homology of 95% between their genomes (Hull et al., 1978). Both phages are efficient transposable elements (for a review, see Toussaint & Rksibois, 1983). Mini-Mu and mini-D108 derivatives that have lost their lytic functions but conserved the ability to transpose were isolated (Faelen et al., Rksibois et al., 1981). The frequency of transposition of miniphages that only provide the A gene product is low but is strongly stimulated in the presence of a helper phage that can be either Mu or D108 (A. Toussaint, personal communication). Since the mini-phage and its helper each code for a thermolabile repressor, their transposition can be induced very efficiently at 42 "C and repressed at low temperature. Upon induction of a lysogen containing a mini A + phage and a helper, both genomes are packaged and the lysate can be used to introduce the mini-phage into sensitive bacteria. This paper reports the use of Mu and D108-1, a mini-D108 derivative carrying Tn9, to demonstrate that one of the plasmids of E. uredovora 20D3 is conjugative. The procedure involved: (i) the isolation of a lysogen carrying D108-1 and Much62 helper phage; (ii) the induction of the prophages resulting in the transposition of Mucts62 and D108-1 to random locations in the genome of 20D3; and (iii) selection for the conjugative transfer of the Cmr marker of D108-1 by mating the induced lysogen with an appropriate recipient. Bacteria, phages and plasmids. These are listed in Table 1, All pla...

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Abnormal cointegrate structures mediated by gene B mutants of phage Mu: Their implications with regard to gene function

1982

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A system where the transposition of MupApl (a derivative of phage Mu carrying a determinant coding for ampicillin resistance) is followed from the small plasmid pML2 into the conjugative plasmid R388 has been used to investigate the influence on Mu transposition of B, an early Mu gene which is involved in normal phage DNA synthesis. In the absence of active B protein a low level (about 1% of normal) of transposition was detected. Roughly a third of these transpositional events was found to lead to the formation of cointegrate DNA structures which were shown to consist of R388, two complete copies of Mu and part only of pML2. The pML2 deletions vary in size but all those investigated appear to originate at an end of Mu. An explanation of these observations is proposed which envisages the B protein as part of the normal transposition complex.

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The isolation and characteristics of plasmids derived from the insertion of MupAp1 into pML2: Their behavior during transposition

Cited by 13 publications

References 19 publications

Plasmid insertion mutagenesis and lac gene fusion with mini-mu bacteriophage transposons

Plasmid insertion mutagenesis and lac gene fusion with mini-mu bacteriophage transposons

Erwinia uredovora 20D3 Contains an IncM Plasmid

Abnormal cointegrate structures mediated by gene B mutants of phage Mu: Their implications with regard to gene function

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