Table 1. A Description of the Nomenclature Used Throughout This Reporta.
| protonation state | q | C4–O(H) | PPi | E126 |
|---|---|---|---|---|
| RO–P–EH | –4 | – | – | H |
| RO–PHEH | –3 | – | H | H |
| ROHP–E– | –4 | H | – | – |
| ROHPHE– | –3 | H | H | – |
| ROHP–EH | –3 | H | – | H |
| ROHPHEH | –2 | H | H | H |
a
This nomenclature is identical to the scheme used previously to describe the IspH oxidized state.50 Unless indicated with an H, the titratable moiety is assumed to be fully deprotonated and is marked by a “–”. The total charge (q) of the active-site quantum cluster when the [4Fe–4S] cluster is 1e– reduced is also given for each state.