Crystallization, calmodulin from

Figure 6-8 Stereoscopic backbone trace of a 148-residue recombinant calmodulin. The two helix-tum-helix (EF-hand) loops and their bound Ca2+ (as concentric circles) are at the top and the two near the C terminus are at the bottom. The long central helix, seen in this crystal structure, may undergo conformational changes during the functioning of this Ca2+-sensing molecule.132 From Chatto-padhyaya et al.m Courtesy of F. A. Quiocho.

FIGURE 5 View of the a-carbon backbone of calmodulin (blue) bound to calmodulin binding domain peptide (red) of smooth muscle MLCK. This view is derived from the crystal structure (Meador et al, 1992) as deposited in the Brookhaven Protein Database (reference number ICDL). The peptide includes hydrophobic residues (yellow), Trp and Leu, at its N and C termini, respectively. 

Figure 17. Lead has been used as a heavy atom derivative to solve the phase problem in the crystal structures of a variety of protein including the calcium proteins calmodulin and synaptotagmin and die zinc protein 5-aminolevulinic acid dehydratase, ALAD. These structures provide useful insights into the coordination environments preferred by lead, which can bind both to carboxylate-rich calcium sites and thiol-rich zinc sites. Structures downloaded from die protein databank (3CLN, IRSY, 1AW5, IQNV) where necessary, lead was added to die figure based upon coordinates provided by the authors (240, 241, 243, 246). Figure adapted from Curr. Opin. Chem. Biol., Vol. 5, H.A. Godwin, The biological chemistry of lead, pp. 223-227, Copyright 2(X)1, with permission from Elsevier Science.

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