Figure 2: Fine mapping of the autoantibody reactivity in epidermolysis bullosa acquisita. (a) Schematic structure of COL7. In vivo, COL7 chains form a trimer. Single COL7 chain consists of one central collagenous domain, flanked by 2 noncollagenous (NC) domains. The N-terminal NC-1 domain consists of several subdomains with high homologies to adhesion proteins (CMP: cartilage matrix-like, Fn3: fibronectin 3-like, and vWFA2: von Willebrand factor A-like). The C-terminal NC2 domain contains conserved cysteine residues, which accompany an antiparallel assembly of these collagen molecules. The COL7 gene (COL7A1) maps to the locus 3p21 [7072]. (b) Summary of epitope mapping studies performed within the NC1 domain. The percentages indicated in the figure correspond the percentage of patients with autoantibodies to their regions.