Figure 2.

Alignment of the amino acid sequence of animal and plant FAD-dependent amine oxidases. Multialignment was done using the program ClustalW sequence alignment (Altschul et al., 1990). Numbering of amino acid residues is shown at the right side. In MPAOs, numbering starts from the first amino acid of the mature protein. The signal peptide of MPAO is underlined. Percentage of identity refers to AtPAO1. Identical residues are indicated by gray boxes. The position of the Cys residue that is covalently linked to the FAD in MAO is indicated by the symbol #. Residues in MPAO putatively involved in the catalytic activity are labeled by the asterisk symbol (*), and the ones composing the tunnel entrance (carboxylate ring and aromatic portion; Binda et al., 2001) are labeled by the symbol ▾. MPAO, Maize PAO; mSMO, murine spermine oxidase; mPAO, murine PAO; Fms1, yeast spermine oxidase.