Aldehyde dehydrogenase gene superfamily: the 2000 update

Aldehyde dehydrogenase (ALDH) superfamily represents a group of NAD(P)(+)-d ependent enzymes that catalyze the oxidation of a wide spectrum of endogeno us and exogenous aldehydes. With the advent of megabase genome sequencing, the ALDH superfamily is expanding rapidly on many fronts. As expected, ALDH genes are found in virtually all genomes analyzed to date, indicating the importance of these enzymes in biological functions. Complete genome sequen ces of Various species have revealed additional ALDH genes. As of July 2000 , the ALDH superfamily consists of 331 distinct genes, of which eight are f ound in archaea, 165 in eubacteria, and 158 in eukaryota. The number of ALD H genes in some species with their genomes completely sequenced and annotat ed, Escherichia coli and Caenorhabditis elegans, ranges from 10 to 17. In t he human genome, 17 functional genes and three pseudogenes have been identi fied to date. Divergent evolution, based on multiple alignment analysis of 86 eukaryotic ALDH amino-acid sequences, was the basis of the standardized ALDH gene nomenclature system (Pharmacogenetics 9: 421-434, 1999). Thus far , the eukaryotic ALDHs comprise 20 gene families. A complete list of all AL DH sequences known to date is presented here along with the evolution analy sis of the eukaryotic ALDHs. (C) 2001 Elsevier Science Ireland Ltd. Ail rig hts reserved.