Part:BBa_K1897011

Invasin

This part was made up of promoter pLuxR BBa_R0062, ribosome binding site (RBS) BBa_B0030, Invasin coding sequence BBa_K1897010 and double terminator BBa_B0015. It is derived from Yersinia pseudotuberculosis, and codes for a 103-kDa membrane surface protein that recognises and binds to β1-integrin on the surface of eukaryotic cells (Isberg and Leong, 1988; McCormick et al., 1997).

Usage and Biology

Invasin allows Yersinia to invade mammalian cells and hide from the immune system. Once invasin binds to β1-integrin on the surface of eukaryotic cells, it is internalised into the cell (Isberg and Leong, 1988). It has been shown by Isberg and Falkow (1985) that with just the invasin gene alone, Escherichia coli can invade mammalian cells expressing β1-integrin. This allows for the entry of E. coli into mammalian cells, and allows for potential delivery of molecules into targeted mammalian cells when used in conjunction with other systems (for example, with the use of quorum sensing, where only in an area of high bacterial cell density will invasin be produced).

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 4
  Illegal XhoI site found at 2791
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal AgeI site found at 976
  Illegal AgeI site found at 2485
  
• 1000
  COMPATIBLE WITH RFC[1000]

Construction and verification of composite Invasin

Invasin was sent for synthesis, and colony screening was done to the transformed Escherichia coli colonies to identify those with the synthesized plasmid (Figure 1).

File:BBa K1897011 Invasin Composite

Figure 1: Gel electrophoresis photo of colony screening done to identify the transformed clones that consisted of the plasmid with invasin. As seen in the gel picture, colonies 1, 2, 4, 5, 7 and 8 had the desired band size of around 3313 bp (Box A).