The Recent De Novo Origin of Protein C-Termini.
Bottom Line: Because we study recent additions to potentially old genes, we are able to apply a variety of stringent quality filters to our annotations of what is a true protein-coding gene, discarding the putative proteins of unknown function that are typical of recent fully de novo genes.We identify 54 examples of C-terminal extensions in Saccharomyces and 28 in Drosophila, all of them recent enough to still be polymorphic.Four of the Saccharomyces C-terminal extensions (to ADH1, ARP8, TPM2, and PIS1) that survived our quality filters are predicted to lead to significant modification of a protein domain structure.
Affiliation: Department of Ecology & Evolutionary Biology, University of Arizona Present address: Aegis Sciences, Nashville, TN.Show MeSH
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Mentions: Among our 54 addition alleles, we identified at least four cases in which the new amino acid sequence can be predicted to cause significant alteration and/or expansion of a protein domain structure. Three of these cases involve frameshift-mediated replacement of sequence integral to a protein domain structure, coupled with addition of varying amounts of sequence at the C terminus (fig. 5); a fourth case involves a pure addition with essentially no sequence replacement. In each of the four cases, secondary structure prediction using Jpred 3 (Cole et al. 2008) suggests the possibility of changes in secondary structure, either within the existing domain structure or as part of a C-terminal extension, or both. We discuss each case in more detail below.Fig. 5.—
Affiliation: Department of Ecology & Evolutionary Biology, University of Arizona Present address: Aegis Sciences, Nashville, TN.