Table 1.
Parameters for the optimized structures of the ternary complexes of tryptophan dioxygenase from Xanthomonas campestris (xcTDO) and human indoleamine 2,3-dioxygenase (hIDO) obtained from quantum mechanical/molecular mechanical simulations
| Parameter | xcTDO | hIDO
|
||
|---|---|---|---|---|
| Cf1A | Cf1B | Cf2 | ||
| d Fe–Op | 1.772 | 1.858 | 1.833 | 1.763 |
| d Op–Ot | 1.313 | 1.312 | 1.312 | 1.314 |
| ∠ Fe–Op–Ot | 124.1 | 121.0 | 120.0 | 120.0 |
| d Fe–Nprox | 2.134 | 2.108 | 2.091 | 2.110 |
| d HTrpNH–Op | – | 3.497 | 2.147 | 2.254 |
| d HTrpNH–Ot | – | 3.611 | 2.651 | 2.157 |
| d C2,Trp–Op | 3.393 | 3.394 | 3.295 | – |
| d C3,Trp–Ot | 3.288 | 3.588 | 4.801 | – |
| d Nε,H55–HTrpNH | 1.673 | – | – | – |
| ∠ NTrpNH–HTrpNH–Nε,H55 | 163.1 | – | – | – |
| ∠ NTrpNH–HTrpNH–Op | – | 92.2 | 133.0 | 149.7 |
The distances (d) and angles (∠) are in angstroms and degrees, respectively. The subscripts p and t for the oxygen atoms refer to the proximal and terminal atoms, respectively
C2,Trp, C3,Trp, HTrpNH, and NTrpNH are the C2 and C3 atoms and the indoleamine hydrogen and nitrogen atoms of L-Trp, respectively. Nprox and Nε,H55 are the nitrogen atom of the proximal His ligand of the heme and the Nε atom of the H55 residue (in xcTDO), respectively