Figure 2.
(A) The two diphosphate oxygen atoms to which the terminal carbon of the substrate may have been connected. (B) Model system to identify optimal angles of deprotonation by the S167 hydroxyl group: methanol and 2,3-dimethyl-2-butene. (C) 2D potential energy scan (vertical axis corresponds to relative electronic energies in kcal/mol; other axes correspond to angles from panel (B) in degrees) showing that the optimal angles are ~120° for A and ~180° for B.