Modeling of the CYP3A4 system began with coordinates obtained from X-ray crystallography (PDB code 1TQN).
Hydrogen atoms were added using VMD.
Missing residues were added using the program MODELLER 9v2 .
For both CYP3A4 in solution and CYP3A4 in POPC membrane simulations the missing residues included 282 to 285 (Lys-Glu-Thr-Glu).
Additionally, for CYP3A4 in a membrane the N-terminal transmembrane helix residues {1–2, 13–27}
have been added to reproduce the sequence of N-terminal truncated CYP3A4 which is used in all experimental studies in our laboratory (plasmid with NF14 construct was a kind gift from F.P. Guengerich).
Crystallographic waters were retained in the model systems.