Additionally, to further contrast the results obtained from our study, we compare the most common coordination shells present in enzymes studied by Laitaoja et al. in their statistical study on Zn(II)-containing protein structures deposited in the PDB (see Table ). Cysteine is the most common residue to coordinate Zn(II) in proteins, making for 33% of the residues, followed by histidine (31%). Aspartic acid and glutamic acid make for 11% and 7%, respectively. Apart from those containing cysteine residues, the most common coordination spheres are those that correspond to mixed Tetrahedral Im-Im-Im-Ac - 2MGT Im-Im-Ac --Ac - 2LI9 Im-Im-Im-Im 5LFY Im-Im-Ac --Ac - Coordination including Aβ 2WK3 Im-Im-Ac --Ac - 3AYU Im-Im-Im-Ac - 4M1C Im-Im-Ac --Ac - 4NGE Im-Im-Ac --Ac - 5LV0 Im-Im-Ac --Ac - 5ONR Im-Im-Ac --Wat generally to Zn(II)-containing metalloproteins.