Table 6.

Distances of ions to the interacting protein residue atoms identified from the 1CK7 X-ray crystal. Statistically significant protein residue atoms as identified by outlier analysis with the associated per residue interaction energies and binding geometry. 1CK7 identified interactions are marked with a dagger (†); statistically significant interactions are marked with an asterisk (*); and binding geometries were determined for those atoms within 0.35 nm. Distance is given in nm and energies in kJ mol^{−1 a,b,c}.

Protein Atom	∆Ebinding	Geometry	Zn2+ Ion 1	Zn2+ ion 2	Ca2+ ion 1	Ca2+ ion 2	Ca2+ ion 3
†*Glu404:Oε1	−154.8223		0.46 ± 0.05
†*Glu404:Oε2			0.48 ± 0.06
†*His403:Nε2	−72.1511	trigonal pyramidal	0.21 ± 0.01
†*His407:Nε2	−66.3450	trigonal pyramidal	0.21 ± 0.01
†*His413:Nε2	−61.5998	trigonal pyramidal	0.21 ± 0.01
†*Asp180:Oδ1	−92.3424	linear		0.19 ± 0.01
†*Asp180:Oδ2		linear		0.19 ± 0.01
†*Asp185:Oδ1		seesaw			0.29 ± 0.16
†*Asp185:Oδ2		seesaw			0.28 ± 0.16
†*Glu211:Oε1	−147.6924	seesaw			0.33 ± 0.11
†*Glu211:Oε2		seesaw			0.35 ± 0.10
†*Asp208:Oδ1	−142.7074	seesaw			0.34 ± 0.09
†*Asp208:Oδ2		seesaw			0.24 ± 0.02
*Asp210:Oδ1	−112.8532	seesaw			0.33 ± 0.14
*Asp210:Oδ2		seesaw			0.35 ± 0.14
Asp168:Oδ1		N/C				2.57 ± 1.59
Asp168:Oδ2		N/C				2.54 ± 1.60
†Ala167:C=O	−1.3321	N/C				2.52 ± 1.75
†Gly200:C=O	0.3799	N/C				2.57 ± 1.70
†Gly202:C=O	−1.0605	N/C				2.55 ± 1.56
*Asp521:Oδ2		N/C					0.98 ± 0.16
†*Asp569:C=O	−79.0260	N/C					0.71 ± 0.18
*Asp569:Oδ1		N/C					0.92 ± 0.15
*Asp569:Oδ2		N/C					0.91 ± 0.15
*Asp490:Oδ1	−69.0106	N/C					1.19 ± 0.11
*Asp490:Oδ2		N/C					1.19 ± 0.11
*Asp615:Oδ1	−68.1150	N/C					1.29 ± 0.14
*Asp615:Oδ2		N/C					1.30 ± 0.14
*Asp153:Oδ1	−63.3125	N/C					2.52 ± 0.96
*Asp153:Oδ2		N/C					2.51 ± 0.95
*Asp472:Oδ1	−54.3377	N/C					1.54 ± 0.15
*Asp472:Oδ2		N/C					1.54 ± 0.15

^a Zn²⁺ ion 1 is the catalytic ion; ^b Glu⁴⁰⁴ is critical to catalytic activity; ^C N/C not coordinated.