Figure 5
Detailed view on the acetyl group of PM (blue) and PL (pink) in the two DFT models. On the left-hand side (model A), His-L168 is protonated in the τ-position forming a hydrogen bond of 1.6 Å to the acetyl group of PL suggesting a moderate hydrogen bonding interaction. The acetyl group of PM does not have a hydrogen bonding partner and is therefore coordinated to the magnesium ion of PL. On the right-hand side (model B), His-L168 is protonated in the π-position. Lacking a partner for hydrogen bonding, the acetyl group of PL coordinates to the magnesium ion of PM. The acetyl group of PM is always coordinated to the magnesium ion of PL. The extended presentations of the two models are shown in the Supplementary Information (Supplementary Figs S1 and S2).
