FIGURE 6.

A putative dimerization interface of β-strand 1. The structure of HuPrP(121–231), highlighting β-strand 1 sequence 127–131 (in red) with an intermolecular distance of 3.9 Å between neighboring Met¹²⁹ residues was recently shown by x-ray crystallography The interface was revealed as a crystal packing interaction (48). Locking the antiparallell configuration of β-strands 1 and 1′ by a disulfide bond in the M129C dimer results in a nonconvertable state. The structure was drawn using the program PyMOL using the Protein Data Bank code 2W9E.