Figure 1.

(a) The X-ray crystal structure (PDB ID: 1E5Q)-derived QM/MM model used to investigate the catalytic mechanism of saccharopine reductase. (b) Schematic representation of the QM/MM model: groups in the inner and outer circles have been modelled at the HF/6-31G(d) and AMBER94 levels of theory, respectively. Note, residues, waters and functional groups in black have been included in the model in their entirety, while residues in red have only had their peptide backbone included.