A Monomerisation does not result in large conformational changes in FICD. Shown is the alignment, from residues 213-407, of FICD molecules in the asymmetric unit. Monomeric FICDL258D and dimeric wild-type FICD ± ATP, are coloured as indicated. Glu234, ATP (and Mg, where applicable), are shown as sticks (or green spheres). The inhibitory alpha helix (αinh) and gross domain architecture is annotated. Note the only significant deviation in tertiary structure is the flipping of the TPR domain in the FICDL258D:ATP structure. The FICD:Apo structure is from PDB: 4U0U. 