2. Right - however, using these systems may present new problems like presence of rare codons. This should also be checked. In addition, it appears from the literature that NS4B is localised in the ER. Can prokaryotic cells support the proper folding of such a protein? We should check what PTMs this protein undergoes. We should also check whether this sequence contains a localization signal and consider removing it before expressing it in bacteria.

3.Right - look at the PDF file "Detergents in RTS".

4. Wrong - Using one of its naturally occuring fusion partners is an interesting idea, but so far we haven't seen any contra-indication to using one of the more frequently used fusion tags or proteins.