The control region of the F sex factor DNA transfer cistrons: Physical mapping by deletion analysis

Thompson, Russell; Achtman, Mark

doi:10.1007/bf00267544

Cited by 54 publications

(14 citation statements)

References 27 publications

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“…Low transfer levels were also reported and similarly interpreted by Miki et al (17). (1,25,26). We also found that while pBE269 exhibited low complementing activity for transfer of F lac traB2 (Table 3), the pBE269/F lac traB strain remained resistant to male specific phages.…”

Section: Resultssupporting

confidence: 89%

“…1. Our fragment sizes were consistent with reports from other laboratories (1,12,13,23,25,26,29,31). However, consideration of available DNA sequence data and the double-digestion patterns of cloned fragments led us to alter the relative positions of some sites depicted on these earlier maps.…”

Section: Resultssupporting

confidence: 89%

“…Although a number of the products associated with these genes have been identified (see refer-ence 31 for a summary), the products associated with others remained elusive. Furthermore, analysis of protein products produced by bacteriophages or plasmids carrying segments of tra DNA has suggested that additional tra-region genes are also present (11,15,21,26). Most of these appear to lie in the less well characterized portions of the tra operon that lie in the traB-traH interval.…”

mentioning

confidence: 99%

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Analysis of transfer genes and gene products within the traB-traC region of the Escherichia coli fertility factor, F

Moore¹,

Wu²,

Kathir³

et al. 1987

J Bacteriol

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A series of plasmids that carry overlapping segments of F DNA encoding the genes in the traB-traC interval was constructed, and a restriction enzyme map of the region was derived. Plasmids carrying deletions that had been introduced at an HpaI site within this interval were also isolated. The ability of these plasmids to complement transfer of F lac plasmids carrying mutations in trail, traV, traW, and traC was analyzed. The protein products of the plasmids were labeled in UV-irradiated cells and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. These analyses showed that the product of traV is a polypeptide that migrates with an apparent molecular weight of 21,000. It was not detected when [35S]methionine was used to label plasmid products, but was readily detected in '4C-amino acid labeling experiments. A 21,500-dalton product appeared to stem from the region assigned to traP. A 9,000-dalton product was found to stem from a locus, named traR, that is located between traV and traC. No traW activity could be detected from the region of tra DNA examined. Our data also indicated that traC is located in a more promoter-proximal position than suggested on earlier maps. The plasmids constructed are expected to be useful in studies designed to identify the specific functions of the traB, -P, -V, -R, and -C products.

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Section: Resultssupporting

confidence: 89%

Section: Resultssupporting

confidence: 89%

mentioning

confidence: 99%

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Analysis of transfer genes and gene products within the traB-traC region of the Escherichia coli fertility factor, F

Moore¹,

Wu²,

Kathir³

et al. 1987

J Bacteriol

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“…In previous analyses of tra products, only one polypeptide of approximately 24,000 Da has been identified, and it was weakly expressed in all cases (1,14,29); no precursor polypeptide was detected. Resolution of tra proteins in this size range is difficult because of the large number of tra proteins close to the 25,000-Da range; this may explain the inability to detect a precursor product.…”

Section: Discussionmentioning

confidence: 89%

“…Attempts to overexpress the TraK protein from the traK-containing fragment of pOSKI placed under the control of an inducible T7 RNA polymerase promoter were unsuccessful. This suggests that TraK expression may be influenced by the presence of one or more tra genes within the larger fragments used previously (1,14,29) to detect the traK gene product.…”

Section: Discussionmentioning

confidence: 97%

The nature of the traK4 mutation in the F sex factor of Escherichia coli

1994

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The sequence of traK gene of the F sex factor of Escherichia coli is presented; the traK gene product is predicted to be a protein of 25,627 Da with a signal sequence of 21 amino acids to give a mature protein of 23,307 Da. The traK4 mutation is an extremely polar mutation in the F plasmid that affects F pilus synthesis and plasmid transfer. traK genes carrying the traK4 mutation and a nonpolar mutation traK105 were cloned, sequenced, and identified as an amber nonsense and a frameshift mutation, respectively. The traK4 mutation occurred within one predicted rho-dependent transcription termination element (TTE) and immediately upstream of another, while the traK105 mutation occurred after the two potential TTEs within the traK gene. S1 nuclease protection analysis and Northern (RNA) blot analysis were used to confirm that the traK4 mutation, but not the traK105 mutation, caused premature termination of transcription. Computer analysis of the F transfer region suggested the presence of TTE motifs at regular intervals throughout the 33.4-kb sequence.

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Intramolecular recombination during plasmid transformation of Bacillus subtilis competent cells.

Michel¹,

Niaudet²,

Ehrlich³

1982

The EMBO Journal

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We have constructed plasmids carrying direct internal repeats 260‐2000 bp long. Monomers of such plasmids transformed Bacillus subtilis competent cells. The efficiency of transformation varied with the square of the length of repeats. The transformed clones harbored either the entire transforming plasmid and the plasmid arising by recombination between the repeats, or only the latter plasmid. Internally‐repeated plasmids linearized by in vitro cleavage with restriction endonuclease could transform, yielding clones which exclusively harbored a plasmid resulting from recombination between the repeats. When the transforming plasmid carried repeats which differed slightly, conversion of one repeat into the other could occur. The following model of plasmid transformation accounts for these data: (1) plasmid DNA is cleaved and rendered linear in contact with competent cells; (2) a linear, at least partially double‐stranded plasmid molecule is introduced or formed by repair within the cell; (3) a circular viable plasmid is produced by recombination between repeats carried on this molecule; (4) alternatively, a viable plasmid is produced by repairing the cut within one of the repeats by DNA synthesis which uses the other repeat as a template.

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The control region of the F sex factor DNA transfer cistrons: Physical mapping by deletion analysis

Cited by 54 publications

References 27 publications

Analysis of transfer genes and gene products within the traB-traC region of the Escherichia coli fertility factor, F

Analysis of transfer genes and gene products within the traB-traC region of the Escherichia coli fertility factor, F

The nature of the traK4 mutation in the F sex factor of Escherichia coli

Intramolecular recombination during plasmid transformation of Bacillus subtilis competent cells.

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