The outer ring of alpha helices is stabilized by the QW-motifs. Should have the common ancestor reconciled with mammals shortly, with the new turtle sequences. The expert on QW repeats is Dr. Georg Schulz . In squalene cyclase protein, they are helix-contiguous and downstream, at least of the first helix bound. The prion protein is membrane-bound through a GPI anchor already.
Normal function is unknown, large enough to be an enzyme.
There are enough hydrophobic and charged residues unassigned to form a plateau, cavity, and monotopic membrane protein. I wonder if several QWs would together form a periodic structure of their own, perhaps a ring or circular pore or gate or structural grid to organize helix attachment. This gets interesting because there are extra QW insertional mutations in cow, chicken, lama, and people. It could make the pore too large or have the wrong QW at the helix, no longer stabilizing it. CJD is not a loss of function disease, it is a loss of structure disease.