Table S2.

Calculated thermodynamic activation parameters for native and mutant BT and AST at 300 K

Enzyme	∆G‡	∆H‡	T∆S‡
BT native*	19.0 ± 1.4	20.4 ± 1.0	1.4 ± 1.0
AST native*	18.2 ± 0.8	9.9 ± 0.6	−8.3 ± 0.6
AST Y97N*	18.4 ± 1.1	12.0 ± 0.8	−6.4 ± 0.8
AST D150S*	18.0 ± 1.1	14.7 ± 0.8	−3.2 ± 0.8
AST K74N	17.8 ± 1.1	16.4 ± 0.8	−1.4 ± 0.8
AST 2X†	17.6 ± 1.6	18.1 ± 1.1	0.4 ± 1.2
AST 3X§	17.5 ± 0.9	17.1 ± 0.6	−0.4 ± 0.6

^*Data taken from ref. 9.

^†Two mutations: Y97N and D150S.

^§Three mutations: K74N, Y97N, and D150S.