Part:BBa_K554009

TolC

TolC is part of the hemolysin secretion system ([http://2011.igem.org/Team:UNICAMP-EMSE_Brazil/Project#Device_3:_Secretion_system Device 3, Protein Secretion System]), very important to export the proteins produced inside bacteria and that must act in targets outside (such as IL-12 and IL-10). TolC is a specific outer membrane protein, which forms a long channel throughout the outer membrane and the periplasm, largely open towards the extracellular medium.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal BamHI site found at 395
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  INCOMPATIBLE WITH RFC[1000]

  Illegal BsaI site found at 247
  

Usage and Biology

You can see a representation of this device acting in the schema below: HlyB gene and product are shown as a symbolic cilinder in orange.

Representation of device 3, the protein secretion system, in a Jedi bacteria that contains Device 1 (Adrenaline sensor/IL-12 producer). To export a protein, the bacteria must have the HlyD, HlyB and TolC proteins and the target protein must have a signal sequence (HlyA tail). In this case, the target protein to be secreted is IL-12.

A more realistic schema of ABC transport system is shown below:

Three-dimensional structure representation

You can find below a tridimensional structure of Crystal structure of the open state of tolc outer membrane protein from Escherichia coli (retrieved from PDB 2VDD (Bavro et al. 2008)) solved by crystallography and X-ray diffraction at 3.3 A resolution. This is a jmol applet, in which you can interactively see the protein structure of TolC:

Molecule: OUTER MEMBRANE PROTEIN TOLC Polymer: 1 Type: protein Length: 460 Chains: A, B, C Fragment: RESIDUES 1-450 Mutation: YES UniProtKB: P02930

References

Barbara D. Tzschaschel, Carlos A. Guzmán,, Kenneth N. Timmis and Victor de Lorenzo. An Escherichia coli hemolysin transport system-based vector for the export of polypeptides: Export of shiga-like toxin IIeB subunit by Salmonella typhimurium aroA. Nature Biotechnology 14, 765 - 769 (1996) [http://www.nature.com/nbt/journal/v14/n6/abs/nbt0696-765.html Article link]

P. Delepelaire. Type I secretion in Gram-negative bacteria. Biochimia et Biophysica Actca 1694, 149-161 (2004) [http://www.ncbi.nlm.nih.gov/pubmed/15546664 Link to PubMed]

Ivaylo Gentschev, Guido Dietrich and Werner Goebel. The E. coli α-hemolysin secretion system and its use in vaccine development. Trends in Microbiology 10, 39-45 (2002) [www.ncbi.nlm.nih.gov/pubmed/11755084 Link to PubMed]

Bavro, V.N., Pietras, Z., Furnham, N., Perez-Cano, L., Fernandez-Recio, J., Pei, X.Y., Truer, R., Misra, R., Luisi, B.Assembly and channel opening in a bacterial drug efflux machine.Journal: (2008) Mol.Cell 30: 114 [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Abstract&list_uids=18406332 Link to PubMed]