Fig. 7.

Modeled structures of the active site of SmBdh and its variants along with their substrates. a Omit Fo-Fc electron density map at 3σ level is shown as a green mesh over acetoin molecules in the active site of the WT SmBdh. b Omit Fo-Fc electron density map at 3σ level is shown as a green mesh over glycerol molecule in the active site of the Q247A SmBdh mutant. c Omit Fo-Fc electron density map at 3σ level is shown as a green mesh over ethylene glycol molecule at the active site of the Q247A + V139Q SmBdh double mutant