Figure 10.

Schematic alignment of M129 with C-terminal LHBH for WT human, FFI human and canine prions. For WT, one S-amide hydrogen bond (with H177) is possible. For FFI, two S-amide hydrogen bonds (with H177 and N178) are possible. For canines (referenced to the human sequence) within the Swiss PDB viewer⁶⁶ rotamer library, no orientation of the R177 could produce amide hydrogen bonding with M129 sulfur. In each case, alignments are produced within the Swiss PDB viewer⁶⁶ by sweeping through low score rotamers and images via VMD.⁶⁷ We identify the small PSKPK loop for domain swapping between tetramers, and the hydrophobic G-A loop pulled from the N2 Model to stabilize the LHBH.