A Ribbon diagram of the FICD dimer interface with monomers in purple and blue ribbons (PDB: 6I7G). Residues involved in a H-bond network linking the dimer interface to the αinh (as well as Gly299 and Glu234) are shown as green sticks. Sub-3.50 Å hydrogen bonds made by Asn236, Leu238 and Lys256 are depicted as dotted cyan lines. 