Steered molecular dynamics simulation (sMD) were performed using GROMACS 2018.4 in order to pull products PRFAR and CdRP out of the active site of the SeHisA(dup13-15/D10G/G102A/Q24L) variant, as described in the Supporting Information. The system preparation was performed as for the conventional MD simulations, and using the same force fields and water models as the conventional MD simulations. Following initial minimization and equilibration, 10 x 50 ns production MD simulations were performed on each system. The first 5 ns of production MD were unrestrained, after which an external force with a force constant of 10 kcal mol -1 Å -2 was applied to pull the product out of the active site. This external force was then released for the last 5 ns of the MD simulation run.