Fig. 3
From: Deciphering the regulatory and catalytic mechanisms of an unusual SAM-dependent enzyme
Activity regulation by SAH/SAM. a Schematic of the overall structure of LepI in complex with SAH. b The density map of SAH. The 2Fo–Fc omit map, contoured at 1.5σ. The SAH molecule is shown in stick. c Structural comparison of MTA/SAM-LepI (blue) and SAH-LepI (gray). d Close-up view of the SAM site between structures of MTA/SAM-LepI (blue) and SAH-LepI (gray). Interactions between SAM and residues (G227, N275, and F276) of LepI are indicated by yellow dashed lines. e Close-up view of the substrate site from MTA/SAM-LepI (blue) and SAH-LepI (gray) structures based on the overall structural alignment. MTA is located at the hydrophobic channel. f Enzymatic assays of the key residues around the SAM-binding site with variants, n.d. represents no detection of activity, (data represent the mean ± s.d.)
