The control region of the F plasmid transfer operon: DNA sequence of the traJ and traY genes and characterisation of the traY → Z promoter

Fowler, Tim; Taylor, Linda; Thompson, Russell

doi:10.1016/0378-1119(83)90038-0

Cited by 50 publications

(30 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the basis of the homology between the nucleotide sequence of R100 with that of F, which has been previously reported (12,15,43,44), the region sequenced was found to contain traM, finP, traA, traL, part of traE, the origin of transfer (oriT), and possibly the traJ and tra Y genes, which are of interest in the present study. The regions are schematically represented in Fig.…”

Section: Resultssupporting

confidence: 59%

“…The tra region of F contains at least 26 genes which are organized into three main operons, traM, traJ, and traYZ (2,19; for a review, see reference 21). Transcription of the tra YZ operon in F and Rl has been shown to be positively regulated at promoter pyz by the product of traJ (8,12,13,16,32). Expression of traJ itself is repressed by the fertility inhibition complex, FinOP, which is composed of the products of two genes, finO and finP, encoded by the R plasmids and F (11,16,32).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Identification and characterization of the products from the traJ and traY genes of plasmid R100

1988

View full text Add to dashboard Cite

The nucleotide sequence of part of the tra region of R100 including traJ and traY was determined, and the products of several tra genes were identified. The nucleotide sequence of traJ, encoding a protein of 223 amino acids, showed poor homology with the corresponding segments of other plasmids related to R100, but the deduced amino acid sequences showed low but significant homology. The first four amino acids at the N-terminal region of the TraJ protein were not essential for positive regulation of expression of traY, the first gene of the traYZ operon. The nucleotide sequence of traY shows that this gene may use TTG as the initiation codon and that it encodes a protein of 75 amino acids. Analysis of the traY gene product, which was obtained as the fusion protein with ,l-galactosidase, showed that the N-terminal region of the product has an amino acid sequence identical to that deduced from the assigned frame but lacks formylmethionine. traY of plasmid F, which encodes a larger protein than the TraY protein of R100, is thought to use ATG as an initiation codon. However, a TTG initiation codon was found in the preceding region of the previously assigned traY coding frame of F. Interestingly, when translation of traY of F was initiated from TTG, the amino acid sequence homologous to the TraY protein of R100 appeared in tandem in the TraY protein of F. This may suggest that traY of F has undergone duplication of a gene like the traY gene of R100.Resistance (R) plasmids such as R100 and Rl, belonging to the FII incompatibility group (4), confer conjugal transfer ability, a process in which DNA is transmitted from one bacterial host to another; this requires cell-to-cell contact and synthesis of sex pili by donor bacteria (for reviews, see references 21, 47, and 48). These plasmids share homology with the fertility factor, F, in the tra region, which is responsible for DNA transfer (41) and which is about 33 kilobase pairs in length. The tra region of F contains at least 26 genes which are organized into three main operons, traM, traJ, and traYZ (2, 19; for a review, see reference 21). Transcription of the tra YZ operon in F and Rl has been shown to be positively regulated at promoter pyz by the product of traJ (8,12,13,16,32). Expression of traJ itself is repressed by the fertility inhibition complex, FinOP, which is composed of the products of two genes, finO and finP, encoded by the R plasmids and F (11,16,32). The initial event in DNA transfer upon expression of the tra YZ operon is strand-and site-specific nicking at the origin of transfer, oriT, by the plasmid-specified endonuclease, which is thought to be a complex of the products of tra Y and traZ (5).In this paper, we report the nucleotide sequence of the promoter-proximal region of tra of R100, including traJ and traY, and the identification of gene products of this region. The plasmids used were R100 (33), pUC19 (49), and pJG200 (17). The pSI plasmids used, except pSI200, are listed in Fig. 1. They were constructed as described below.Construction of pSI ...

show abstract

Section: Resultssupporting

confidence: 59%

mentioning

confidence: 99%

Identification and characterization of the products from the traJ and traY genes of plasmid R100

1988

View full text Add to dashboard Cite

show abstract

“…In the case of the related F-like conjugative plasmids, the roles of TrwA seem to be performed by the conjunction of the oriT-binding proteins TraY and TraM, which are functionally redundant to some extent (44). Both proteins, like R388 TrwA, are involved in transcriptional regulation of transfer genes and in activating the relaxase nicking activity (29,(45)(46)(47). Protein TraY is homologous only to the N-terminal DNA-binding domain of TrwA.…”

Section: Discussionmentioning

confidence: 99%

Conjugative coupling proteins interact with cognate and heterologous VirB10-like proteins while exhibiting specificity for cognate relaxosomes

Llosa

Zunzunegui

Cruz

2003

Proc. Natl. Acad. Sci. U.S.A.

127

185

View full text Add to dashboard Cite

Conjugative coupling proteins (CPs) are proposed to play a role in connecting the relaxosome to a type IV secretion system (T4SS) during bacterial conjugation. Here we present biochemical and genetic evidence indicating that the prototype CP, TrwB, interacts with both relaxosome and type IV secretion components of plasmid R388. The cytoplasmic domain of TrwB immobilized in an affinity resin retained TrwC and TrwA proteins, the components of R388 relaxosome. By using the bacterial two-hybrid system, a strong interaction was detected between TrwB and TrwE, a core component of the conjugative T4SS. This interaction was lost when the transmembrane domains of either TrwB or TrwE were deleted, thus suggesting that it takes place within the membrane or periplasmic portions of both proteins. We have also analyzed the interactions with components of the related IncN plasmid pKM101. Its CP, TraJ, did not interact with TrwA, suggesting a highly specific interaction with the relaxosome. On the other side, CPs from three different conjugation systems were shown to interact with both their cognate TrwE-like component and the heterologous ones, suggesting that this interaction is less specific. Mating experiments among the three systems confirmed that relaxosome components need their cognate CP for transfer, whereas T4SSs are interchangeable. As a general rule, there is a correlation between the strength of the interaction seen by two-hybrid analysis and the efficiency of transfer.

show abstract

“…Given the data in this paper, it is evident that traJ has only an indirect role of promoting expression of tra. Further, the ability of pRPZ133 (9,15,29). Furthermore, the need for one or more host proteins in oriT nicking has not been discounted.…”

Section: Discussionmentioning

confidence: 99%

“…1. The design of several of the tracontaining plasmids was greatly aided by availability of tra sequence data (5,9,10,28).…”

Section: Methodsmentioning

confidence: 99%

traY and traI are required for oriT-dependent enhanced recombination between lac-containing plasmids and lambda plac5

Carter

Porter

1991

J Bacteriol

View full text Add to dashboard Cite

Recombination between F421ac and Xplac5 is typically 20-to 50-fold more efficient than recombination between chromosomal lac and Xplac5. This enhancement of recombination requires trans-acting factors located in the promoter-distal and promoter-proximal regions of the main traY-to-tral (traZ) operon. By testing the ability of deletion mutants of tra to support enhanced recombination, we have identified traY as the only essential gene from the promoter-proximal region of tra. The possibility of a direct role for the traJ gene product has been ruled out. We also report that tral is the only gene from the promoter-distal end of the traY to tral operon that is required for recombination enhancement. Of the two proposed domains of tral, we conclude that the oriT-nicking activity is essential, whereas the helicase activity is largely dispensable. The possibility of a third tral activity is also discussed.

show abstract

The control region of the F plasmid transfer operon: DNA sequence of the traJ and traY genes and characterisation of the traY → Z promoter

Cited by 50 publications

References 34 publications

Identification and characterization of the products from the traJ and traY genes of plasmid R100

Identification and characterization of the products from the traJ and traY genes of plasmid R100

Conjugative coupling proteins interact with cognate and heterologous VirB10-like proteins while exhibiting specificity for cognate relaxosomes

traY and traI are required for oriT-dependent enhanced recombination between lac-containing plasmids and lambda plac5

Contact Info

Product

Resources

About