Analysis of the promoter-distal region of the tra operon of the F sex factor of Escherichia coli K-12 encoded by EcoRI restriction fragments f17, f19, and f2

Manning, Paul A.; Kušećek, Barica; Morelli, Giovanna; Fisseau, Claudine; Achtman, Mark

doi:10.1128/jb.150.1.76-88.1982

Cited by 26 publications

(13 citation statements)

References 31 publications

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“…pBE93 carried an insertion mapping between a traG::TnS (pBE83) and a traT::TnS (pBE95) insertion. This is the same relative location as that of the F-traS cistron (16). Cell envelopes from cells carrying pBE93 contained normal amounts of R100-TraTp (Fig.…”

Section: Resultsmentioning

confidence: 53%

“…F-TraIp has the unusually high molecular weight of 175,000 (16,18,32). A protein comigrating with F-TraIp was detected with all the insertion mutants of pSM6, although longer exposures of the film were needed than used in Fig.…”

Section: Resultsmentioning

confidence: 98%

“…The fact that many of the colonies were poor recipients in conjugation with donor cells carrying R100-1 indicated that pSM6 probably encodes cistrons corresponding to the F factor's surface exclusion cistrons, traS and traT. Because the traI cistron of F maps within the DNA region corresponding to that present in pSM6 (16), pSM6 would be expected to carry a traI analog. However F-Tralp is not replaceable by introducing R100-1 (plasmid specificity) so that the lack of complementation of F-traI40 by pSM6 is not interpretable.…”

Section: Resultsmentioning

confidence: 99%

“…Furthermore, the surface exclusion of these two mutants against R100-1 was elevated when the recipients also carried F' lac+, i.e., complementation was observed. Thus these two insertions locate R100-traT, which maps between R100-traG and R100-traD, just as F-traT maps between F-traG and F-traD (16). pBE93 carried an insertion mapping between a traG::TnS (pBE83) and a traT::TnS (pBE95) insertion.…”

Section: Resultsmentioning

confidence: 99%

“…Transposon mutagenesis and other techniques. Transposon mutagenesis and other techniques were carried out as described (16).…”

Section: Methodsmentioning

confidence: 99%

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Promoter-distal region of the tra operon of F-like sex factor R100 in Escherichia coli K-12

Hansen¹,

Manning²,

Achtman³

1982

J Bacteriol

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The distal region of the tra (transfer) operon of F-like plasmid R100 was investigated, using small plasmids derived from R100, primarily the plasmid pSM6. The transposon TnS (which confers kanamycin resistance) was inserted at different positions into pSM6, and the transposition derivatives were tested for ability to complement defined tra mutants of the F sex factor. Thus, the tra genes traH, G, T, and D were localized on the plasmid R100. A restriction map of pSM6 was constructed, and the locations of the insertions were mapped, using restriction endonuclease digestion of the plasmid DNA and exploiting the fact that several restriction sites are localized in the inverted repeat regions of the transposon. The gene products of the genes traG, S, T, and D were identified by radioactive labeling of proteins synthesized in minicells carrying the various insertion plasmids followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The presence of another transfer gene, tral, was inferred from these data. Another protein, the r2-A protein, was also identified, and its gene was mapped. On the basis of the data, a best-fit physical map of this region of the tra operon of R100 was constructed. The results confirmed that the general order and size of the distal transfer genes is as in the F sex factor, but showed that differences exist with respect to all of the gene products. The significance of these differences are discussed in the light of the genetic and physical homology (Manning et al., J. Bacteriol. 150:76-88) of the transfer regions.

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Section: Resultsmentioning

confidence: 53%

Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

“…Transposon mutagenesis and other techniques. Transposon mutagenesis and other techniques were carried out as described (16).…”

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Promoter-distal region of the tra operon of F-like sex factor R100 in Escherichia coli K-12

Hansen¹,

Manning²,

Achtman³

1982

J Bacteriol

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Endonuclease activity of Escherichia coli DNA helicase I directed against the transfer origin of the F factor.

et al. 1991

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DNA helicase I, the traI gene product of the Escherichia coli F factor, was shown to be associated with endonuclease activity specific for the transfer origin of the F plasmid, oriT. In the presence of Mg2+, the purified enzyme forms a complex, stable in the presence of sodium dodecylsulfate (SDS) with a negatively superhelical chimeric plasmid containing oriT. The enzyme nicks and, after this, apparently binds to the 5′ nick terminus when this complex is heated in the presence of SDS and/or EDTA or treated with proteinase K. Dideoxy sequencing locates the nick site in the F DNA strand transferred during bacterial conjugation after nucleotide 138 clockwise of the mid‐point of the BglII site at 66.7 kb of the F genetic map. A sequencing stop after nucleotide 137 of this strand (where oriT‐nicking seems to occur in vivo) is possibly an artefact caused by helicase I protein attached to the 5′ terminal nucleotide. Deletion in the amino‐terminal part of the traI polypeptide abolishes the oriT‐nicking activity while leaving the strand‐separating activity intact. These results confirm the prediction from genetic studies that helicase I is bifunctional with site‐specific endonuclease and strand‐separating activities.

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Cyclic AMP and its receptor protein are required for expression of transfer genes of conjugative plasmid F in Escherichia coli

Kumar

Srivastava

1983

Mol Gen Genet

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A number of cya and crp mutants of Escherichia coli HfrH were analyzed for several Tra functions of the F plasmid. The mutants were observed to be deficient in conjugal donor ability, absorption of phages MS2 and Q beta and surface exclusion. These defects were suppressed in cya mutants grown with cAMP supplementation. A cAMP concentration of 3 X 10(-4) M produced maximal suppression of donor ability defect in a cya strain. cAMP did not suppress the Tra- phenotype of crp mutants. Latent periods of MS2 were shorter in cya and crp bacteria. Phage T7 development appeared similar in wild type, cya, and crp cells. It is concluded that tra genes of F plasmid are expressed only to a small extent in cya and crp mutants and that cAMP and its receptor protein are required for the normal expression of tra genes.

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Analysis of the promoter-distal region of the tra operon of the F sex factor of Escherichia coli K-12 encoded by EcoRI restriction fragments f17, f19, and f2

Cited by 26 publications

References 31 publications

Promoter-distal region of the tra operon of F-like sex factor R100 in Escherichia coli K-12

Promoter-distal region of the tra operon of F-like sex factor R100 in Escherichia coli K-12

Endonuclease activity of Escherichia coli DNA helicase I directed against the transfer origin of the F factor.

Cyclic AMP and its receptor protein are required for expression of transfer genes of conjugative plasmid F in Escherichia coli

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