Table 1.

Geometrical parameters for the reactant and transition from Minimum Energy Path (MEP) analysis for the phosphoryl transfer reaction of model UNP with different hydrogen-bonding interactions between the nucleophile (2’-OH) and phosphate^a

Geometrical Parametersb	DH	1W
P-O7	3.396 (0.015)/2.270 (0.100)	4.140 (0.042)/2.900 (0.199)
P-O12	1.646 (0.001)/1.670 (0.008)	1.665 (0.014)/1.635 (0.012)
P-O8	1.696 (0.005)/1.665 (0.014)	1.670 (0.017)/1.621 (0.010)
P-O11/14	1.517 (0.004)/1.636 (0.009)	1.515 (0.004)/1.600 (0.005)
H22-O7	0.994 (0.001)/1.742 (0.040)	0.989 (0.001)/1.578 (0.029)
H22-O11/14	1.781 (0.011)/0.989 (0.006)	N/A
∠O7-P-O12	126.5 (0.6)/162.1 (1.3)	124.3 (5.0)/156.0 (4.1)
∠O7-H22-O11/14-P	35.6 (0.5)/−1.2 (2.0)	N/A
H22-OW	N/A	1.867 (0.059)/1.019 (0.007)
HW-OW	N/A	1.000 (0.004)/1.953 (0.075)
HW’-O11/14	N/A	1.727 (0.059)/0.993 (0.001)

^a)The results are averaged over snapshots collected from aqueous solution simulations that include either a direct hydrogen bond (DH) between the nucleophile and phosphate or a single bridging water molecule (1W). The numbers without parentheses are the average values and those with parentheses are standard deviations (9 snapshots for DH and 7 snapshots for 1W). All structures have been optimized at the B3LYP/6–31+G* level in the gas phase. Values before the slash are for the reactant state, and those after the slash are for the transition state.

^b)Distances are in angstrom; angle and dihedral angles are in degrees. For labels of atoms, see Fig. 1; the subscript “W” indicates the bridging water in 1W cases, and O_11/14 means either O₁₁ or O₁₄, whichever acts as the proton acceptor during the nucleophilic attack.