FIGURE 1.

(a) Structure of CaM bound to its highest affinity target peptide (M13), as determined by NMR spectroscopy (8): CaM (red) and M13 (blue) C_α chains are drawn as ribbons; the side chains of the two anchors (W-4 and F-17), which bind to the C- and N-domains, are represented as yellow and green sticks, respectively. (b) PDB entries and peptide sequences of the 15 CaM/peptide complex structures which have been determined so far (anthrax edema factor, which is a CaM/protein complex (58), is not included here). The helical regions (as defined by the program DSSP (42)) are boxed. The two anchors (10) are colored as in panel a. For convenience, sequences are printed with the first of the two anchors aligned.