In this paper, we wished to examine the extractability and usability, especially in foreign protein structural contexts, of a 40 residues-long ‘beta finger’ or ‘beta tongue’ motif which is present in many different transmembrane beta-structure-based pore forming toxins like alpha-hemolysin form Staphylococcus aureus. The beta finger consists of an 18 residues-long beta strand forming an antiparallel beta sheet with another 18 residues-long beta strand, with a tight beta turn of 4 residues joining the two strands. We could not make the 40 residues-long construct, and so we made a construct in which two identical copies of the construct were fused to create something which was 80 residues long.

Click to Read in Detail