Table 2. Summary of MD simulations on wild type AmtB and His variants, and deduced conductivity compared to that observed in vivo.

	Protein	Substrate	t simulation (ns)	t exiting (ns)	Conductivity (fromsimulation)	Conductivity (fromexperiment)
A1	wild-type	CH3NH2	20	13.950	Conductive	Conductive
A2	wild-type	NH3	20	1.792	Conductive	Conductive
B1	H168A	CH3NH2	100	–	Nonconductive	Nonconductive
B2	H168A	NH3	20	4.415	Conductive	Conductive
C1	H318A	CH3NH2	100	–	Nonconductive	Nonconductive
C2	H318A	NH3	20	8.860	Conductive	Conductive
D1	H168A/H318A	CH3NH2	20	5.190	Exit to periplasm	Nonconductive
D2	H168A/H318A	NH3	40	37.460	Exit to periplasm	Nonconductive
D3	H168A/H318A	CH3NH2	100	3.700	Exit to cytoplasm	Nonconductive
D4	H168A/H318A	NH3	100	78.420	Exit to cytoplasm	Nonconductive
D5	H168A/H318A	–	20
D6	H168A/H318A	–	20

The initial location of the substrate is always at site Am2. Simulations D5 and D6 both without substrate are designed to explore the intrinsic dynamic property of the conformations of the Phe gate (F107 and F215).