Figure 6.

PFR beta structure: the front view shows long-lasting protective and short-live protection inducers. The colour code is the same as that used in Figure 3. Black sticks highlight the backbone of N-terminal peripheral region residues forming β-turn or α-helixes. Note that most structures were left-hand orientated suggesting an interaction with the HLA-DR α-chain to collaborate in stabilising this complex. Also note the total absence of the most frequent β-turn types, such as I, II and II’.