Conserved Residues in the Aldehyde Dehydrogenase Family

Abstract

As described in the preceding chapter (Liu et al., 1996), features of the class 3 ALDH Rossmann fold were totally unexpected. While Gly-187 is involved in binding NAD, its role is completely different from that observed for the first glycine residue of the GXGXXG motif in other dehydrogenases with traditional Rossmann folds. It was thus of interest, once the sequence was fit into the electron density, to examine the locations of strictly conserved residues from our earlier multiple sequence alignment (Hempel et al., 1993). A total of 23 residues were strictly conserved in that alignment. This chapter will confine itself to an attempt to correlate the role of the strictly conserved residues in the ALDH family with the class 3 ALDH (binary complex with NAD) tertiary structure.