Table 2. The "door keeper" rule of inhibitor binding in Co-CA.
Inhibitor, atom | Zinc | Gly-107, NH | Asp-49, Oδ2 |
(Distance (Å)) | (Distance (Å)) | (Distance (Å)) | |
HPO4 2-,O | 2.0 | 2.8 | 3.6 |
N3-, N | 2.0 | 2.8 | 3.8 |
SCN-, N | 2.0 | 3.4 | 3.8 |
I-, OH (H2O) | 2.3 | 3.4 | 2.9 |
AZM, NH | 2.0 | 3.6 | 3.1 |
When zinc-binding groups are protonated, a hydrogen bond is formed to the side chain of the hydrogen acceptor Asp-49. If the zinc-bound group is not protonated, a hydrogen bond is formed to the main chain amide group of the hydrogen donator Gly-107.