title: Compositional relatedness of aldehyde reductases from several species.
abstract: The amino acid compositions of several monomeric NADPH-dependent aldehyde reductases from a variety of species have been determined and analyzed by the difference index method of Metzger et al. (1968). The difference indexes among mammals range from 4.15 - 6.10 indicating considerable homology. Comparison of chicken aldehyde reductase with mammalian aldehyde reductases gave values in the range 6.8 - 9.9 suggesting a close relationship whereas the difference indexes for the enzymes from fruit fly and Baker's yeast versus vertebrate aldehyde reductases (10.9 - 14.4) indicate more distant relationships. The extent of sequence homology among aldehyde reductases from these species was estimated from a plot of difference index versus percent sequence difference for oxido-reductases of known sequence. From this plot, and using a mammal-chicken divergence time of 300 million years and a mammalian order split of 75 million years, the rate of evolution of aldehyde reductases was calculated to lie in the range 5.8 - 15.6% sequence difference per 100 million years. Comparison with rates of evolution of oligomeric dehydrogenases indicates that aldehyde reductases comprise the most rapidly evolving family of oxido-reductases. This is probably related to the monomericity of aldehyde reductases since there is a direct correlation between the number of subunits and the rate of evolution.
mesh_terms: D000445:Aldehyde Oxidoreductases / Q000032:analysis*; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D005075:Biological Evolution; D002645:Chickens / Q000378:metabolism; D004330:Drosophila / Q000201:enzymology; D007668:Kidney / Q000201:enzymology; D008099:Liver / Q000201:enzymology; D009249:NADP / Q000378:metabolism; D051381:Rats; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D013045:Species Specificity
chemical_list: D000596:Amino Acids; D009249:NADP; D000445:Aldehyde Oxidoreductases