Figure 2: Topology arrangement of main chain-main chain hydrogen bonds (blue lines) within wild-type monomeric subunits and at monomer-monomer interfaces H-H’ (Figure 1(b)) and F-F’ (Figure 1(c)). Letters A to H designate the -strands in one monomer while H’ and F’ belong to the other monomer of the same dimer. Red arrows indicate the connection between strands and show the loop regions and blue ones go from donor (NH) to acceptor (OC). Coloured residues (yellow) are the ones involved in the mutation and is the helical region between strands E and F.