The enzyme is a hexamer, forming the largest structurally known ketolisomerase, and has no sequence or structural similarity with other ketol isomerases. The structure was determined by X-ray crystallography at 2.5 Angstrom resolution.[1] Each subunit of the hexameric enzyme is wedge-shaped and composed of three domains. Both domains 1 and 2 contain central parallel beta- sheets with surrounding alpha helices. The active centre is shared between pairs of subunits related along the molecular three-fold axis, with domains 2 and 3 from one subunit providing most of the substrate-contacting residues.[1]
^ abSeemann JE, Schulz GE (October 1997). "Structure and mechanism of L-fucose isomerase from Escherichia coli". J. Mol. Biol. 273 (1): 256–68. doi:10.1006/jmbi.1997.1280. PMID9367760.