I've been trying to express a protein in the cytosol of E. coli. I'm only
getting very low yields. The protein is predicted to contain a disordered
region of at least 40 amino acids. Would this be enough to explain the low
yields? The disordered region is at the very N-terminus - I truncated the
protein in a loop region after two transmembrane regions. Why do
disordered regions have a negative effect on expression yields - is it
just because they are likely to be targets for proteases or are the other
factors? I've found that adding a tag to the protein greatly increases the
yields. Is that just because the disordered region is no longer at the
N-terminus? I appreciate that tags can have other positive effects e.g. on
the solubility of the protein.
Any help in this matter would be MUCH appreciated.