Disease relevance of traC

• Cross-linking identified protein-protein interactions of TraC in E. coli carrying pKM101 but not derivatives with transposon insertions in essential tra genes [1].

High impact information on traC

• TraC of the IncN plasmid pKM101 belongs to the VirB5 family of proteins, an essential component of most type IV secretion systems [2].
• VirB5/TraC is a single domain protein, which consists of a three helix bundle and a loose globular appendage [2].
• TraC of IncN plasmid pKM101 associates with membranes and extracellular high-molecular-weight structures in Escherichia coli [1].
• Overexpression of TraC and its export in large amounts into the periplasm of Escherichia coli allowed purification by periplasmic extraction, ammonium sulfate precipitation, and column chromatography [1].
• VirB4 shares amino acid sequence similarity with the TraC protein of plasmid F, which is essential for pilus formation in Escherichia coli, and with the PtlC protein of Bordetella pertussis, which is required for toxin secretion [3].

Anatomical context of traC

• Whereas TraC was soluble in overexpressing strains, it partly associated with the membranes in pKM101-carrying cells, possibly due to protein-protein interactions with other components of the TraI-TraII region-encoded transfer machinery [1].
• Biochemical and cell biological experiments presented here show extracellular localization of TraC, as suggested by extracellular complementation of TraC-deficient bacteria by helper cells expressing a functional plasmid transfer machinery (S. C. Winans, and G. C. Walker, J. Bacteriol. 161:402-410, 1985) [1].

References