   1.21.99.3 | structure of the catalytic domain of mouse deiodinase Dio3, to 1.9 A resolution. The catalytic Sec170 is positioned in the loop connecting beta1 to alpha1. It points toward an elongated cleft that likely represents the iodothyronine binding site. The deiodination step follows a selenolate inline attack on the iodine delta-hole weakening the carbon-iodine bond. The abstracted iodonium is replaced by a proton approaching from the opposite side of the ring. The proton is conveyed to the 5-position of the iodothyronine along a triad His219, Glu200, and Ser167, with residues Tyr197 and Thr169 participating in the organization of an intricate H-bond network |
735180 |
