Our team: Me and my colleague Yousif Graytee, Baghdad, Iraq (from **Designer Cells Lab at Yonsei University, Incheon, South Korea)** did the final project related to bacteriophage together and the result is available in this notion page!

Credit: This whole page is written by Yousif Graytee, Baghdad, Iraq

Our Goal: Make lysis independent of DNAj by separating C-terminal from N-terminal

Our Idea:

Introduction: The L-protein depends on its interaction with DNAj in order to interact properly with its target (which is unknown). This is largely due to the highly soluble N-terminal of the L-protein which has been proven to be dispensable for function. Most of the gene that encodes the lysis protein overlaps with two other genes (cp gene & rep gene):

However, there is a small, 33 nucleotide long (11 codons), region of the L-protein encoding gene that doesn’t overlap with any other gene:

The N-terminal of the L-protein is 34 amino acids long, while the L-protein as whole is 75 amino acids. 17 of the total 34 amino acids are encoded within the overlap with the Coat protein gene:

As for the rest of the protein, which is any part that is not the N-terminal and is therefore including the transmembrane domain responsible for lysis, then it is encoded for within the overlap with the replicase gene:

Explanation:

Since there is a region that is 33 nucleotides long which doesn’t overlap with any other genes, and this region doesn’t encode for the functional part of the L-protein but is rather encoding for part of the N-terminal:

We can introduce a stop codon within this region to separate the N-terminal of the L-protein from the C-terminal. This approach wouldn’t lead to changes in any of the other proteins encoded for by the MS2 phage genome, and would still encode for the N-terminal. That way, whether the N-terminal can interact with DNAj or not, it wouldn’t affect lysis as the C-terminal can operate independently and carry out it’s function. This would be taking the approach done in previous studies, where truncations of the C-terminal were shown to be sufficient for lysis, however, instead of completely removing the N-terminal out of the picture, we have merely separated them so as to not affect the other proteins encoded for in the genome.

It is also believed that the L-protein encounters steric hinderance when attempting to interact with its target (which is unknown). This is again believed to be due to the N-terminal. The N-terminal’s interaction with DNAj is what frees up this hinderance, thereby allowing the C-terminal to initiate lysis: