Table 2. Transport mechanism and energetics in NeRh50 proteins^*.

Mechanism*	Supporting evidence	Possible energetics	References
5&	- Electroneutral transport pH dependent - Resistance to MeA toxicity	pH gradient dependent Δψ independent	[72,75,76]
6	- Presence of CO2 binding pocket in crystal structure	CO2 concentration gradient	[77]
5	- MD simulation computing potentials of mean force and permeabilities for NH3	NH3 chemical gradient	[78]
2	- Electroneutral transport in lipososmes - Independent of pH gradient	pH gradient independent Δψ independent	[12]

^*Mechanism: 2 - NH₄⁺ deprotonation following by NH₃/H⁺ conduction, 5 - NH₃ uniport, 6 - CO₂ transport, &- the activity may be bidirectional activity.