Disease relevance of traM

• We then used the screening procedure to identify a mutation in a gene homologous to traM of Agrobacterium tumefaciens, which was able to suppress the phenotype of the groELc mutation [1].
• Merodiploid strains containing transposon insertion mutations either in traM or in neighboring tra genes were used to demonstrate that traM constitutes a new complementation group essential for conjugation and donor phage sensitivity [2].

High impact information on traM

• Induction of traM in a strain in which TraR was activating transcription of a reporter system led to rapid cessation of gene expression [3].
• Using the yeast two-hybrid system, constructs of Saccharomyces cerevisiae containing a fusion of traR to the B42 domain of the prey plasmid pJG4.5 and a fusion of traM to the lexA gene of the bait plasmid pEG202 produced beta-galactosidase and grew on medium lacking leucine, both phenotypes indicative of an interaction between the two proteins [4].
• Deletion of traM2 in strain A6 harboring the mutated traM confers a constitutive QS phenotype [5].
• Intriguingly, the QS-constitutive phenotype appeared when the pTiA6 carrying the mutated traM was placed in the chromosomal background of the nopaline-type strain C58C1RS, suggesting an unknown inhibitory factor(s) encoded by the chromosomal background of strain A6 but not by C58C1RS [5].
• In A. tumefaciens A6, the expression of the attKLM operon is controlled by the transcriptional repressor encoded by an adjacent gene, attJ [6].

Biological context of traM

• Mutations in traM in pTiC58 conferred a transfer-constitutive phenotype, and strains harboring the Ti plasmid produced easily detectable amounts of AAI [7].
• Analysis of the DNA sequences of the genes required for conjugal transfer suggested the existence of a previously uncharacterized open reading frame, designated traM, that might be required for conjugation [2].
• Mutagenesis of the fourth regulatory gene, traM, had no effect on transfer [8].
• This element is strikingly similar in sequence to the binding site for the yeast Migl protein, a transcriptional repressor of genes involved in the utilisation of carbohydrates other than glucose [9].

Other interactions of traM

• The suppression could be relieved by increasing the expression of TraR but not by increasing AAI levels. traM is located between traR and traAF on pTiC58 and is transcribed in the clockwise direction [7].

Analytical, diagnostic and therapeutic context of traM

• Low-stringency Southern blotting analysis showed that strain A6, but not strain C58 and its derivatives, contains a second traM homologue [5].

References