Structural highlights
Function
TRAM1_ECOLI Conjugative DNA transfer (CDT) is the unidirectional transfer of ssDNA plasmid from a donor to a recipient cell. It is the central mechanism by which antibiotic resistance and virulence factors are propagated in bacterial populations. Part of the relaxosome, which facilitates a site- and strand-specific cut in the origin of transfer by TraI, at the nic site. Cooperatively binds 3 regions in the F plasmid oriT locus; 2 are required for autoregulation while the other is required for plasmid transfer. Bends oriT DNA less than 50 degrees. Plasmid specificity is conferred by the TraD-TraM pair.[1] [2] [3] [4]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
F plasmid-mediated bacterial conjugation requires interactions between a relaxosome component, TraM, and the coupling protein TraD, a hexameric ring ATPase that forms the cytoplasmic face of the conjugative pore. Here we present the crystal structure of the C-terminal tail of TraD bound to the TraM tetramerization domain, the first structural evidence of relaxosome-coupling protein interactions. The structure reveals the TraD C-terminal peptide bound to each of four symmetry-related grooves on the surface of the TraM tetramer. Extensive protein-protein interactions were observed between the two proteins. Mutational analysis indicates that these interactions are specific and required for efficient F conjugation in vivo. Our results suggest that specific interactions between the C-terminal tail of TraD and the TraM tetramerization domain might lead to more generalized interactions that stabilize the relaxosome-coupling protein complex in preparation for conjugative DNA transfer.
Structural basis of specific TraD-TraM recognition during F plasmid-mediated bacterial conjugation.,Lu J, Wong JJ, Edwards RA, Manchak J, Frost LS, Glover JN Mol Microbiol. 2008 Oct;70(1):89-99. Epub 2008 Aug 19. PMID:18717787[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Di Laurenzio L, Frost LS, Paranchych W. The TraM protein of the conjugative plasmid F binds to the origin of transfer of the F and ColE1 plasmids. Mol Microbiol. 1992 Oct;6(20):2951-9. PMID:1479887
- ↑ Penfold SS, Simon J, Frost LS. Regulation of the expression of the traM gene of the F sex factor of Escherichia coli. Mol Microbiol. 1996 May;20(3):549-58. PMID:8736534
- ↑ Fekete RA, Frost LS. Characterizing the DNA contacts and cooperative binding of F plasmid TraM to its cognate sites at oriT. J Biol Chem. 2002 May 10;277(19):16705-11. Epub 2002 Mar 1. PMID:11875064 doi:http://dx.doi.org/10.1074/jbc.M111682200
- ↑ Ragonese H, Haisch D, Villareal E, Choi JH, Matson SW. The F plasmid-encoded TraM protein stimulates relaxosome-mediated cleavage at oriT through an interaction with TraI. Mol Microbiol. 2007 Feb;63(4):1173-84. PMID:17238924 doi:http://dx.doi.org/10.1111/j.1365-2958.2006.05576.x
- ↑ Lu J, Wong JJ, Edwards RA, Manchak J, Frost LS, Glover JN. Structural basis of specific TraD-TraM recognition during F plasmid-mediated bacterial conjugation. Mol Microbiol. 2008 Oct;70(1):89-99. Epub 2008 Aug 19. PMID:18717787 doi:10.1111/j.1365-2958.2008.06391.x
