Compact archived record and sequence evidence for P09130
Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
Structural basis of specific TraD-TraM recognition during F plasmid-mediated bacterial conjugation.
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The TraD C-terminal peptide binds four symmetry-related grooves on a TraM tetramer, the first structural evidence of a relaxosome-coupling protein interaction.
"The structure reveals the TraD C-terminal peptide bound to each of four symmetry-related grooves on the surface of the TraM tetramer."
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The TraD-TraM interaction is specific and required for efficient F conjugation in vivo, which is the evidence behind the existing conjugation annotation.
"Mutational analysis indicates that these interactions are specific and required for efficient F conjugation in vivo."
The carboxyl terminus of protein TraD adds specificity and efficiency to F-plasmid conjugative transfer.
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TraD belongs to the coupling-protein family that also contains TrwB of R388, TraG of RP4 and VirD4 of Agrobacterium, whose members share transmembrane domains and nucleotide-binding sequence signatures.
"Proteins encoded by these genes, which are termed the TraG protein family, show significant similarities among their amino acid sequences and share transmembrane domains and sequence signatures for nucleoside triphosphate binding"
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The C-terminal tail is the specificity determinant: truncating it broadens the range of relaxosomes TraD will serve while reducing F transfer efficiency.
"The change in specificity was due to a loss of some amino acids in the carboxyl terminus of TraD that resulted in a broadening of the range of mobilizable relaxosomes at the expense of a decrease in the efficiency of F-plasmid transfer."
The cytoplasmic DNA-binding protein TraM binds to the inner membrane protein TraD in vitro.
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TraM binds TraD in vitro, demonstrated by overlay assay and affinity chromatography. This is the first evidence of the relaxosome contact later resolved structurally.
"the affinity of TraM to TraD was studied in vitro by an overlay assay and by affinity chromatography."
TrwB, the coupling protein involved in DNA transport during bacterial conjugation, is a DNA-dependent ATPase.
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TrwB, the R388 coupling protein and a member of the same family as TraD, has a characterised DNA-dependent ATPase activity. This is the basis for inferring ATP hydrolysis for TraD.
"In this work, we characterize a DNA-dependent ATPase activity for TrwBDeltaN70."
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The soluble domain of TrwB crystallises as a hexamer with a central channel, matching the hexameric ring architecture attributed to TraD.
"TrwBDeltaN70 crystallographic structure revealed a hexamer with six equivalent subunits and a central channel."
The bacterial conjugation protein TrwB resembles ring helicases and F1-ATPase.
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TrwB recruits the relaxosome, the same role TraD performs for F, so the family correspondence is functional and not merely one of sequence.
"This large multimeric protein is responsible for recruiting the relaxosome DNA-protein complex"