Figure 6: Structures of VcFadR and EcFadR with ligand.

(a) The VcFadR-oleoyl-CoA complex in two orientations. The ligand in the site corresponding to EcFadR (see c) is shown in pink spheres, whereas the ligand in the site that involves the insertion is in yellow spheres. (b) The chemical structure of oleoyl-CoA. (c) Structure of EcFadR bound to myristoyl-CoA (PDB 1H9G)¹⁷. (d,e) Regions boxed in a highlighting critical residues interacting with the ligand in the pocket of VcFadR corresponding to that of E. coli (d, site no. 1, monomer A) and in the pocket derived from the insertion (e, site no. 2, monomer A). Positively charged residues that interact with ligand phosphates are in blue. Residues forming hydrogen bonds are cyan, and those forming hydrophobic interactions are in green. Y153, which forms π-stacking with adenosine of the ligand, is wheat. Residues from chain B are distinguished by a prime following the amino-acid number. The ligand is shown as sticks in d,e. The carbon atoms are coloured pink in d and yellow in e. Other atoms of the ligand are coloured as follows: nitrogen, blue; oxygen, red; sulfur, dark yellow; phosphorous, orange.