FIG. 5.

Partial alignment of the ALDH2 protein sequence, of the aldehyde dehydrogenases from S. mutans and V. harveyi, and of BoxD from A. evansii. Conserved amino acids which function in cofactor binding and specificity are highlighted by letters in boldface type, the catalytic cysteine residue is highlighted in black, the two conserved glutamate residues that might function in the activation of the cysteine nucleophile are highlighted in gray, and the histidine residue that is involved in the catalytic mechanism of the V. harveyi enzyme and eventually BoxD is highlighted by a capital letter.