IGEM:MIT/2007/Notebook/2007-6-20

To-Do

 * 1) Research: find a peptide sequence small enough to express as the passenger protein in eCPX
 * 2) Grad meeting at 3


 * Grad meeting canceled

Interpretation of CPX Paper
So, we've been wondering how the CPX (circularly permutated OmpX) ends up with the N- and C-termini on the surface of bacteria. At first, it seemed like Rice05 translated the native OmpX gene, stuck it into the membrane, connected the native termini, and then cleaved Loop 2, leaving a new N- and C- termini on the surface (and consequently, the passenger protein). The paper actually describes a completely genetic modification, there is no post-mRNA translation modification. If you look at Figure 1, you can compare the initial OmpX sequence to the CPX sequence. After translation of the CPX sequence, the passenger protein is already a terminus and loop 2 the other terminus. At this point, translated CPX will fold similarly to translated OmpX and finally be transported to the membrane, where the passenger protein and loop 2 will stick out of the membrane as the new termini.