Figure 4.

Comparison of helix 3 in hPrP(121–230) and mPrP(121–231), where the backbone of the polypeptide segment 215–224 is represented as a spline function drawn through the C^α positions. The figure results from a global superposition of the two proteins for best fit of the backbone atoms of the residues 144–154, 175–193, and 200–219, which correspond to the α-helices in mPrP. The following color code was used: yellow and orange, backbone and C^β atoms of hPrP(121–230), respectively; cyan and light blue, backbone and C^β atoms of mPrP(121–231), respectively; green, d_αβ(i, i + 3) and d_αN (i, i + 3) NOE distance constraints observed in hPrP; magenta, same types of NOE constraints observed for mPrP (11).