Disease relevance of traA

• Agrobacterium tumefaciens and the susceptible plant cell: a novel adaptation of extracellular recognition and DNA conjugation [1].
• Recent work has shown that several pathogens of plants and mammals - Agrobacterium tumefaciens, Bordetella pertussis, Helicobacter pylori and Legionella pneumophila - have evolved secretion pathways ancestrally related to conjugation systems for the purpose of delivering effector molecules to eukaryotic target cells [2].
• Bacterial conjugation is also classified as a TFSS-like process mediating the spread of broad-host-range plasmids between Gram-negative bacteria such as RP4 and R388, which carry antibiotic resistance genes [3].
• However, when an E. coli strain expressing the IncN-type conjugation system was coinoculated with a disarmed A. tumefaciens strain, plant tumors arose at high frequencies [4].
• The conjugation frequency, stability and copy number of replicons carrying mini-Mulac derivatives with oriT and oriRiHRI in members of the Rhizobiaceae such as Rhizobium meliloti, Azorhizobium caulinodans ORS571 and Agrobacterium tumefaciens C58 was examined [5].

High impact information on traA

• Here we show that conjugation is regulated directly by a transcriptional activator, TraR, which requires conjugation factor as a coinducer to activate tra gene expression [6].
• Conjugation factor of Agrobacterium tumefaciens regulates Ti plasmid transfer by autoinduction [6].
• Conjugal opines secreted by crown gall tumours induce strains of Agrobacterium tumefaciens that are donors of Ti plasmids to produce a diffusible conjugation factor [7].
• It is, to our knowledge, the first example of a second messenger molecule in a bacterial conjugation system [7].
• The two regulatory systems are related; the two activator proteins show amino-acid sequence similarities and the lux system cofactor, autoinducer, will substitute for conjugation factor in the TraR-dependent activation of Ti plasmid tra genes [6].

Chemical compound and disease context of traA

• Conjugation of Agrobacterium tumefaciens wide-host-range octopine-type Ti plasmids is regulated by the LuxR-type transcriptional activator TraR in conjunction with an acylated homoserine lactone designated AAI [8].

Biological context of traA

• The characteristics of the VirD1/VirD2-mediated cleavage reaction strongly resemble those observed with relaxosomes of IncP plasmids involved in initiation of transfer DNA replication during bacterial conjugation [9].
• Expression of trlR inhibited octopine-induced conjugation of pTi15955 and pTiR10 by suppressing the TraR-mediated transcription of the tra and trb operons [10].
• The effect of these vir gene mutations upon conjugation could be restored by the introduction of cosmids harboring wild-type copies of the corresponding disrupted vir genes into the mutant Agrobacterium strains [11].
• The circular concept of the bacterial chromosome was based initially on experiments involving conjugation mapping and autoradiographic imaging of DNA [12].
• Mpf/CP conjugation systems belong to the family of type IV secretion systems (T4SS), which also includes DNA-uptake and -release systems, as well as effector protein translocation systems of bacterial pathogens such as Agrobacterium tumefaciens (VirB/VirD4) and Helicobacter pylori (Cag) [13].

Anatomical context of traA

• We have established a novel method of gene introduction into eukaryotic cells by trans-kingdom conjugation between Escherichia coli/Agrobacterium tumefaciens bacteria and yeasts [14].

Associations of traA with chemical compounds

• Physical characterization of 13 transposon Tn5 insertions within the agrocinopine-independent, transfer-constitutive Ti plasmid pTiC58Trac identified three separate loci essential for conjugation of this nopaline/agrocinopine A + B-type Ti plasmid [15].
• Conjugation of wide-host-range octopine-type Ti plasmids requires a tumor-released arginine derivative called octopine [16].
• Unlike VirE2, GALLS contains a nucleoside triphosphate binding motif similar to one in TraA, a strand transferase conjugation protein [17].
• Finally, the rhizogenic potential of in vitro-cultured leaf explants excised from antisense plants was significantly diminished as compared with WT ones, and the response to methyl jasmonate, a stress-mimicking compound, in terms of PA conjugation, was higher and differentially affected in transgenic leaf discs relative to WT ones [18].
• Modification of T-DNA of nopaline Ti plasmid by intermediary vector and utilization of agrocin 84 sensitivity as simple criterion of conjugation transfer of modified Ti plasmid [19].

Other interactions of traA

• The genes specifying production of octopine or nopaline by the tumor were transferred to recipient bacterial strains when the large plasmid associated with virulence was transferred by either conjugation or deoxyribonucleic acid-mediated transformation [20].

Analytical, diagnostic and therapeutic context of traA

• By use of a sensitive, quantifiable assay termed transfer DNA immunoprecipitation (TrIP), we identify contacts between a DNA substrate (T-DNA) and 6 of 12 components of the VirB/D4 conjugation system of the phytopathogen Agrobacterium tumefaciens [21].
• The Cercospora kikuchii cercosporin export gene, CFP, introduced into Beta vulgaris L. by conjugation with Rhizobium radiobacter, was stably maintained during vegetative propagation as verified by PCR using primers specific for the CFP gene [22].

References