The computational models of Ccr were constructed based on the crystal structure of the ternary complex of K. setae Ccr (KsCcr, PDB ID: 6NA4) and representative structures from previous work. This complex displays a tetrameric arrangement, organized as a dimer of dimers. Each dimer comprises one closed and one open subunit (designated as subunits A/C and B/D), with the closed subunits representing the catalytically active form of the enzyme (subunits A and B). Each subunit includes a NADPH cofactor, with the closed subunits also containing the substrate analogue butyryl-CoA. Details regarding system preparation, parametrization, and initial equilibration of the system are documented in previous work. Representative structures of reactants and the enolate intermediate from a converged string simulation, describing the direct mechanism, were used to model the hydride transfer reaction. These two states served as the start and end points for the subsequent reaction modeling studies discussed below.