Sandbox Reserved 1069: Difference between revisions

'''Binding Site C'''

<scene name='69/694236/Bsc/1'>Binding site C</scene> has vastly opposite properties from what is seen in binding site A. It is located on the TM2-TM3 loop on the cytoplasmic membrane and between the two C-terminus domain interfaces. Here, there is a binuclear coordination of Zn²⁺ between the <scene name='69/694236/Asp285/3'>Asp285</scene> residue that bridges the Zn²⁺ ions together and the four coordinating residues (<scene name='69/694236/His232/2'>His232</scene>, <scene name='69/694236/His248/1'>His248</scene>, <scene name='69/694236/His283/1'>His283</scene> and <scene name='69/694236/His261/1'>His261</scene>). The Asp285 residue is conserved, meaning it does not have outer shell constraints, however, the same cannot be said for the four histidine residues. These constraints consist of hydrogen bonds to the residues surrounding the binding site allowing bidentate bond formation, or hydrogen bonding to a metal in two places. Formation of bidentate bonds creates an extensive network of interactions at the CTD interface, which allow for stability and strengthening of the CTD-CTD association.