Fig. 2: X-ray crystal structures of SyoA in the open substrate-free and closed substrate-bound states.
From: Structural insights into S-lignin O-demethylation via a rare class of heme peroxygenase enzymes
Ribbon diagram showing the overall architecture of SyoA in the (a) open conformation (PDB: 8u09, blue) highlighting the positions of the heme (white sticks), sixth axial water (red sphere) and glycerol (GOL, orange/red sticks). b, c Active site of the open conformation showing the key active site residues highlighting the solvent molecules and Fe-OH2 distance (blue dashed line). Ribbon diagram showing the overall architecture of SyoA in the (d) closed conformation (PDB: 8u19, purple) showing the positions of the heme (white) and substrate syringol (yellow/red). e, f Active site of the closed conformation highlighting key active site residues; black dashed lines illustrate the distance of the 2-methoxy group of syringol from the Fe center, and the hydrogen bonding distance between the 1-hydroxyl group of syringol and the backbone carbonyl of Val245. Superposed structures of the open and closed form of SyoA showing the g overall fold and h active site. Only the helices that have an average Cα RMSD of 3 Å or greater are colored in (g) with angle of displacement ~18.6° indicated by an arrow. The eye symbol (b) indicates the viewing angle of (b) relative to the structure shown in (a). The view of the active site in (c, f) is made by rotating (b, e) respectively ~160° clockwise about the y-axis, and ~45° clockwise about the z-axis.
