Part:BBa_K3788018

timer-lysis device

Introduction :

It is composed from a part of the caa gene coding for the Colicin A toxin. This part also contains cal and cai genes coding respectively for the lysis-protein CaL and the immunity protein Cal.

In normal conditions, caa and cai genes are positioned as an operon, and the cai gene is located on the antisense strand and expressed in a constitutive manner.

This system’s regulation is constituted from many regulation elements, which permits it to obtain a fine-tuned regulation.

This system is located on a plasmid present in some E. Coli populations. It allows Colicin A accumulation on the host cell, and then induces its death due to CaL action, which provokes Colicin A liberation on the extracellular medium, which induces the death of bacteria that don’t produce Cal protein.

cal gene codes for CaL protein, a lipopeptid with a length between 28 and 48 amino acid residues. This protein is produced as a precursor and then processed. Once the protein is processed, it can form pores in the bacterial membrane, which leads to the quasi-lysis of the host cell, and provokes a leak from the cellular component into the medium.

Design :

A GFP coding sequence (BBa_E0040) has been inserted at the 5’ extrimity of the caa gene, which conserves the internal regulation elements present in the caa nucleotdiic sequence. This construction will allow the characterisation of the LexA-repressed promoter (BBa_K3788017) what gives the composite part BBa_K3788019.

Sequence and Features

Assembly Compatibility:

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

  Illegal NheI site found at 585
  
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal BglII site found at 905
  Illegal BamHI site found at 578
  Illegal XhoI site found at 454
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal NgoMIV site found at 654
  
• 1000
  INCOMPATIBLE WITH RFC[1000]

  Illegal SapI.rc site found at 408