Figure 4.

The crystal structure of the collagen IV^α345hexamer. In the GBM, collagen IV^α345 scaffold is built from α345 protomers, where the NC1 hexameric complex is a key assembly unit (left). The crystal structure of the α345 hexamer is shown as a backbone wire-frame (middle) depicting loops (GP hypoepitopes) and the chloride ring at the trimer–trimer interface. The corrected surface model (right) depicts the appropriate chain pairing and sulfilimine crosslinks (S = N; shown in red). GBM, glomerular basement membrane.