Structural comparisons of the A441 region of ALDH10 isoenzymes. A) Superimposition of the side-chains of residues at position 441, 443 and 456 (SoBADH numbering) in the known crystal structures of plant ALDH10 enzymes. Side-chains are shown as sticks with oxygen atoms in red, nitrogen in blue, and sulphur in yellow. Carbon atoms are green in SoBADH (PDB code 4A0M), cyan in PsAMADH2 (PDB code 3IWJ), magenta in ZmAMADH1a (PDB code 4I8P), and black in SlAMADH1 (PDB code 4I9B). B) Superimposition of the same region in the minimized models of the in silico SoBADH mutants in which the residue at position 441 was changed. Side-chains are shown as sticks with oxygen atoms in red, nitrogen in blue, and sulphur in yellow. Carbon atoms are green in the wild-type enzyme, magenta in A441C, grey in A441S, yellow in A441T, brown in A441V, salmon in A441F, and cyan in A441I. In the figure, the wild-type and A441T models mask the A441C and A441S models, respectively. The figure was generated using PyMOL (http://www.pymol.org).