The prototypical locus control region orchestrates expression of this protein’s subunits. The movement of the proximal histidine transitions this protein into a less active form. A shunt in glycolysis creates this protein’s allosteric regulator 2,3-BPG, (10[1])which right-shifts this protein’s cooperative S-shaped binding curve. A change in pH shifts this protein’s curve in the Bohr effect. The adult form of this protein contains two alpha and two beta chains, each of which is bound to a porphyrin ring. Carbon monoxide binds to this protein (10[1])more strongly (10[1])than its usual partner. For 10 points, name this iron-containing protein in red blood cells that carries oxygen. ■END■