Team:THIS-China/Improved part

Improved Parts – comD

Team CCU_Taiwan in 2017 provides the simple explanation of the comD gene and its relationship with the comDE system and CSP. When using this system, we discovered a few potential problems.

First of all, the previous group that used comD did not precisely show that the comD expressed successfully. Furthermore, they did not mention whether comD attaches to the membrane and successfully detects the CSP signal. We construct two plasmids to allow the comD to successfully express.

However, we found out that, while the membrane protein comD does express, it cannot properly function and detect the CSP. We then did thorough research about this protein, and found out that it is different than other membrane proteins, since it is a protein that does not have a signal peptide. This means that it has to rely on the hydrophobic amino acid to be correctly folded and put onto the membrane.

We then made sure that it is actually the hydrophobic amino acids that help this protein to get onto the membrane. We analyzed the different types of amino acids in the comD protein, and found that 43 percent of the amino acids are hydrophobic.

This fact makes it difficult for the proteins to be formed and correctly transferred onto the membrane. Some of the solutions we propose involve changing the cultivation environment for the bacteria. For example, the temperature, the type of bacteria we use, codon optimization, etc. are all possible solutions.

Figure 1: Amino Acids in the ComD protein.