Evolutionary and functional relationships within the DJ1 superfamily.
|Title||Evolutionary and functional relationships within the DJ1 superfamily.|
|Publication Type||Journal Article|
|Year of Publication||2004|
|Authors||Bandyopadhyay S, Cookson MR|
|Journal||BMC Evol Biol|
|Date Published||2004 Feb 19|
|Keywords||Amino Acid Sequence, Animals, Avian Proteins, Caenorhabditis elegans Proteins, Cercopithecus aethiops, Chickens, Conserved Sequence, Cricetinae, Drosophila Proteins, Evolution, Molecular, Fish Proteins, Humans, Intracellular Signaling Peptides and Proteins, Mesocricetus, Mice, Molecular Sequence Data, Multigene Family, Oncogene Proteins, Phylogeny, Rats, Salmo salar, Sequence Homology, Amino Acid, Xenopus Proteins|
BACKGROUND: Inferences about protein function are often made based on sequence homology to other gene products of known activities. This approach is valuable for small families of conserved proteins but can be difficult to apply to large superfamilies of proteins with diverse function. In this study we looked at sequence homology between members of the DJ-1/ThiJ/PfpI superfamily, which includes a human protein of unclear function, DJ-1, associated with inherited Parkinson's disease.
RESULTS: DJ-1 orthologs in a variety of eukaryotic species cluster together in a single group. The most closely related group is the bacterial ThiJ genes. These are kinases involved in the biosynthesis of thiamine, a function that has been dispensed with evolutionarily in most eukaryotes where thiamine is an essential nutrient. The similarity with other characterized members of the superfamily, including proteases, is more remote. This is congruent with the recently solved crystal structures that fail to demonstrate the presence of a catalytic triad required for protease activity.
CONCLUSION: DJ-1 may have evolved from the bacterial gene encoding ThiJ kinase. However, as this function has been dispensed with in eukaryotes it appears that the gene has been co-opted for another function.
|Alternate Title||BMC Evol. Biol.|