Fig. 4.

Loop VII makes amyloid-filament-like interactions with neighboring molecules in the crystals of 4 different SOD1 mutants. (A) Close-up of the interaction between loop VII and 2 edge β-strands of the neighboring molecule. (B) Overview of the crystallographic 2-fold interaction seen in the present work. (C) Superposition of the intermolecular interaction seen in the present work (orange) with the interactions seen in the dimeric structures of the ALS mutants H46R (1OZT, green) and S134N (1OZU, cyan), and the dimeric Zn-free mutant H80S/D83S (2R27, blue). (D) The fibril-like arrangement of protein seen in crystals of the dimeric Zn-deficient SOD1 mutants (Right) and the situation in monomeric Zn-misligated SOD1 (Left).