PDBsum entry 3gbg

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protein ligands links
Transcription regulator PDB id
Protein chain
260 a.a. *
Waters ×217
* Residue conservation analysis
PDB id:
Name: Transcription regulator
Title: Crystal structure of toxt from vibrio cholerae o395
Structure: Tcp pilus virulence regulatory protein. Chain: a. Engineered: yes
Source: Vibrio cholerae. Organism_taxid: 345073. Strain: o395. Gene: tcpn, toxt, vc0395_a0363. Expressed in: escherichia coli. Expression_system_taxid: 562.
1.90Å     R-factor:   0.214     R-free:   0.245
Authors: M.J.Lowden,F.J.Kull
Key ref:
M.J.Lowden et al. (2010). Structure of Vibrio cholerae ToxT reveals a mechanism for fatty acid regulation of virulence genes. Proc Natl Acad Sci U S A, 107, 2860-2865. PubMed id: 20133655 DOI: 10.1073/pnas.0915021107
19-Feb-09     Release date:   23-Feb-10    
Go to PROCHECK summary

Protein chain
Pfam   ArchSchema ?
A5F384  (TCPN_VIBC3) -  TCP pilus virulence regulatory protein
276 a.a.
260 a.a.
Key:    PfamA domain  Secondary structure  CATH domain

 Gene Ontology (GO) functional annotation 
  GO annot!
  Cellular component     cytoplasm   1 term 
  Biological process     pathogenesis   3 terms 
  Biochemical function     DNA binding     3 terms  


DOI no: 10.1073/pnas.0915021107 Proc Natl Acad Sci U S A 107:2860-2865 (2010)
PubMed id: 20133655  
Structure of Vibrio cholerae ToxT reveals a mechanism for fatty acid regulation of virulence genes.
M.J.Lowden, K.Skorupski, M.Pellegrini, M.G.Chiorazzo, R.K.Taylor, F.J.Kull.
Cholera is an acute intestinal infection caused by the bacterium Vibrio cholerae. In order for V. cholerae to cause disease, it must produce two virulence factors, the toxin-coregulated pilus (TCP) and cholera toxin (CT), whose expression is controlled by a transcriptional cascade culminating with the expression of the AraC-family regulator, ToxT. We have solved the 1.9 A resolution crystal structure of ToxT, which reveals folds in the N- and C-terminal domains that share a number of features in common with AraC, MarA, and Rob as well as the unexpected presence of a buried 16-carbon fatty acid, cis-palmitoleate. The finding that cis-palmitoleic acid reduces TCP and CT expression in V. cholerae and prevents ToxT from binding to DNA in vitro provides a direct link between the host environment of V. cholerae and regulation of virulence gene expression.
  Selected figure(s)  
Figure 1.
The structure of ToxT. (A) Ribbon diagram of ToxT showing α-helices (gold), β-strands (cyan), and loops (dark red). The bound cis-palmitoleate is shown in stick form with carbons in green and oxygens in red. The N and C termini are indicated. Helices and strands are numbered according to their topological connectivity in the full-length protein. Note that residues 101–110 are disordered in the structure, as indicated by the loop ends on the left side of the molecule. (B) Close up of the cis-palmitoleate binding region showing interactions of the carboxylate head group with side chains.
Figure 2.
Ribbon diagrams of ToxT and the N- and C-terminal domains of AraC. The models are colored by a rainbow effect with blue at the N terminus and red at the C terminus. The arabinose bound in the N-terminal domain of AraC is shown in stick form. PDB accession numbers are indicated for the three structures.
  Figures were selected by an automated process.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
21215638 J.Yang, M.Tauschek, and R.M.Robins-Browne (2011).
Control of bacterial virulence by AraC-like regulators that respond to chemical signals.
  Trends Microbiol, 19, 128-135.  
20862321 A.T.Nielsen, N.A.Dolganov, T.Rasmussen, G.Otto, M.C.Miller, S.A.Felt, S.Torreilles, and G.K.Schoolnik (2010).
A bistable switch and anatomical site control Vibrio cholerae virulence gene expression in the intestine.
  PLoS Pathog, 6, 0.  
20562308 G.Kovacikova, W.Lin, and K.Skorupski (2010).
The LysR-type virulence activator AphB regulates the expression of genes in Vibrio cholerae in response to low pH and anaerobiosis.
  J Bacteriol, 192, 4181-4191.  
20363935 P.Domínguez-Cuevas, J.L.Ramos, and S.Marqués (2010).
Sequential XylS-CTD binding to the Pm promoter induces DNA bending prior to activation.
  J Bacteriol, 192, 2682-2690.  
20507887 V.Mahon, C.J.Smyth, and S.G.Smith (2010).
Mutagenesis of the Rns regulator of enterotoxigenic Escherichia coli reveals roles for a linker sequence and two helix-turn-helix motifs.
  Microbiology, 156, 2796-2806.  
The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time.