Example Tabs

Gene expression control

All substances are poisons. There is none which is not a poison. The right dose differentiates a poison and a remedy. Paracelsus

In order to make our device - the BactoDHL functioning correctly we had to express each gene in the right dose. To high expression of certain proteins, especially the LLO (listeriolysin) would be toxic to the cells. To low expresion would result in poor performance of our device.

Because our devices are encoded as operons wefaced two different problems at two different levels:

  • Global expression regulation of the whole operon, which is controlled at promoter level
  • Local expression regulation of each gene in the operon, which is controlled at the RBS level

To solve this problem determined absolute strength two promoters we were interested in: J23100 and pT7. Results indicate how much mRNA is created per amount of DNA here.

We have also determined relative strength of 10 RBS from 2010 DNA distribution. Results are here.

We have used the measurement results to create ExpressIt! defined expression strength vectors kit.

Results from those experiment were crucial in designing suitable kill switch and invasion operon (stage 2 and 3 of our project).

We explored a shortcut to information about RBS strength - computational modeling. Can we replace RBS measurement with modeling?