Polyamine Oxidase Oxidoreductase This protein contains a flavin adenine dinucleotide shown in spacefilling. Binda, C., Coda, A., Angelini, R., Federico, R., Ascenzi, P., Mattevi, A.: A 30-Angstrom-Long U-Shaped Catalytic Tunnel in the Crystal Structure of Polyamine Oxidase Structure (London) 7 pp. 265 (1999) (PubMed) 1b37 pdb