Figure 2.

EF-hand motif 1 of EhCaBP1 showing the heavy-metal coordination. (A) Calcium coordination in the calcium binding loop-1 of EhCaBP1. Calcium coordinates with seven of its ligands including one water molecule to satisfy the coordination geometry. The coordination distances are shown. (B) Lead coordination in the calcium binding loop-1 of EhCaBP1. Lead co-ordinates with six ligands in the EF-hand motifs. The coordination distances between the Pb2+ and ligand oxygen atoms for EF-hand 1 motif range between 2.1 Ǻ and 2.8 Ǻ. (C) Strontium coordination in the calcium binding loop-1 of EhCaBP1. Strontium co-ordinates with seven ligands in the EF-hand motif. The coordination of Sr2+ is similar to that of Ca2+ coordination except for the absence of water molecule in the coordination. The 3rd aspartate residue is donating both of its oxygen ligands to satisfy the coordination geometry. The coordination distances between the ion and oxygen atom for the EF-hand 1 motif range between 2.1 Ǻ and 2.8 Ǻ. (D) Barium coordination in the calcium binding loop-1 of EhCaBP1. Barium coordinates with seven ligands including one water molecule to satisfy the coordination geometry. The coordination distances are shown. The coordination of Ba2+ is similar to that of Ca2+. The coordination distances between the ion and oxygen atom for EF-hand 1 motif range between 2.4 Ǻ and 2.9 Ǻ.

Kumar et al. BMC Biophysics 2012 5:15   doi:10.1186/2046-1682-5-15
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