Sandbox Reserved 1069: Difference between revisions

It is important to note that the structure of this binding site is rigid because of the coordination of the Zn²⁺ between the four residues. This rigidity is indicative that any slight shift on either of the helices will cause a drastic readjustment of the coordination of Zn²⁺. In addition, there are no outer-shell constraints to hold the residues in place, which means that with a readjustment of the molecule, there is no energy being expended to bind or release another Zn²⁺ molecule. Therefore, the Zn²⁺ is able to rapidly release and a new Zn²⁺ can bind again with a simple reorientation or shift of the molecule. This rapid on off bind and release mechanism is the regulator of homeostatic levels of Zn²⁺ in the cell. This regulation is significantly faster than other Zn²⁺ exchange rate proteins by several orders of magnitude.