Compositional relatedness of aldehyde reductases from several species |
| |
Authors: | William S Davidson T Geoffrey Flynn |
| |
Institution: | (1) Group in Eukaryotic Molecular Biology and Evolution, Departments of Biochemistry and Biology, Queen's University, K7L 3N6 Kingston, Ontario, Canada;(2) Present address: Department of Biochemistry, University of California, 94720 Berkeley, CA, USA |
| |
Abstract: | Summary 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. |
| |
Keywords: | Aldehyde reductase Dehydrogenases Compositional relatedness Evolutionary rates |
本文献已被 SpringerLink 等数据库收录! |
|