Copper‐binding conformations and PrP octarepeat sequence mutations The structure of full‐length PrP and derivative C1 and C2 fragments with an enlarged view of the cleavage sites is shown. Copper‐binding conformations and PrP octarepeat sequence mutations The structure of full‐length PrP and derivative C1 and C2 fragments with an enlarged view of the cleavage sites is shown. The C2 (β) site was mapped in HpL3‐4 cells by (Mange et al, 2004). Ragged C1 (α) cleavage sites in brain are shown (Chen et al, 1995), and a dotted arrow indicates that additional sites have been mapped rightward of this position in vitro (McDonald et al, 2014). Ragged N‐terminal cleavage sites of PrP27‐30 from prion‐infected mouse brain are indicated by small arrows (Howells et al, 2008). The positions of antibody epitopes are also shown (residues in brackets). Grey shading reflects the minimum length for a C2 fragment defined operationally by reactivity with 12B2 antibody. S1 and S3 alleles, by virtue of limited geometries (modified from Chattopadhyay et al, 2005), may have access to distinct subsets of the full range of biological activities of WT PrP, which has access to interchangeable component 1, 2 and 3 geometries. Sequences of synthetic PrP alleles differing in the octarepeat region of mouse PrP. Conserved histidines in octarepeats 2–5 are coloured blue and missense mutations are shown in red. Overproduction of C2 fragment is indicated by ++ signs to the right of the panel. Agnes Lau et al. EMBO Mol Med. 2015;emmm.201404588 © as stated in the article, figure or figure legend