Three-dimensional structures of S100B, S100A1, S100A6 and S100A11 have shown that calcium binding to these proteins results in a conformational change allowing them to interact with many biological targets. The structures of some S100 proteins in the presence of peptide targets from Ndr kinase, p53, CapZ, annexins A1 and A2 and the Siah-1 Interacting Protein indicate there are at least three mo...