Team:Dundee Schools/Design
RNA Interference
RNA interference (RNAi) is the inhibition of gene expression by small interfering RNA (siRNA) molecules binding to complementary messenger RNA (mRNA) sequences and so stopping translation of that protein. Our team has decided to use this method to stop the translation of a virulence gene required for our target bacteria to cause infection.
spiRNA
By using the process of RNAi we needed to create a siRNA that specifically targets Vibrio cholerae and Shigella. It will then inhibit the target bacterium and bind to a virulence gene blocking the production of that important protein. We have decided to rename our small interfering RNA Agent spiRNA.
S.O.R.D.
In order for us to even begin to target the bacteria Shigella and Vibrio cholerae we had to come up with a way of getting our spiRNA outside of the E. coli. We decided to focus on the protein OsmY naturally found in E. coli that is regularly secreted from the bacteria. As Hfq is an RNA binding protein it will be able to bind with our spiRNA and fusing it with OsmY creates a predicted RNA secretion device that we have named S.O.R.D. (Secretor Of RNA Device).
Expression system
Each spiRNA can be separated into two main parts, each having their specific function; the first being a sequence specific to binding with Hfq and the second being a sequence specific to the gene we want to target.
The blue area is the part that will bind to the Hfq in our fusion protein - using the binding site from micC for E. coli and chiA for Serratia. Then to make the spiRNA specific to the bacteria we want to target, we’ll add in a target-binding sequence. This is the red area and the sequence will be complimentary to the first 24bp on the mRNA strand.
A future plan for our project would be that both our expression system and our fusion protein would be on one plasmid.
References
https://internationalmedicalcorps.org/sslpage.aspx?pid=1145
http://www.healthline.com/health/shigellosis#Overview1
