 | Acta Crystallographica Section F Acta Crystallographica Section F STRUCTURAL BIOLOGY COMMUNICATIONS |
journal menu
![[Figure 3]](gx5109fig3mag.jpg)
|
|
Figure 3
The mechanism of catalysis by B. anthracis 5-formyl-THF cyclo-ligase. (a) A cut-through of the 5-formyl-THF cyclo-ligase structure showing the cofactor/substrate-binding pocket with bound ADP and phosphate. The enlarged view shows 2Fo − Fc electron density contoured at 1.5σ (green) for these moieties. Weak electron density (not shown) suggests that the substrate/product binds in the right-hand side of this pocket. (b) A ball-and-stick diagram showing the octahedral coordination of the Mg2+ ion by the α- and β-phosphates of ADP, residues Asp144 and Asp173 and two tightly bound water molecules. Interaction distances are shown in Å. This coordination helps orient the γ-phosphate of ATP correctly for attack on the 5-formyl-THF. The green lines show 2Fo − Fc electron density contoured at 2.2σ. (c) The proposed catalytic mechanism of B. anthracis 5-formyl-THF cyclo-ligase via a phospho-enol intermediate. Our structure represents the final stage of the process, after the product has dissociated from the binding pocket. |
![[Figure 3]](gx5109fig3.jpg)
| STRUCTURAL BIOLOGY COMMUNICATIONS |
ISSN: 2053-230X
