Searching the Resource Information Network
Are you sure you want to leave this community? Leaving the community will revoke any permissions you have been granted in this community.
Glutamine tandem repeats are common in eukaryotic proteins. Although some studies have proposed that replication slippage plays an important role in shaping these repeats, the role of natural selection in glutamine tandem repeat evolution is somewhat unclear. In this study, we identified all of the glutamine tandem repeats containing four or more glutamines in human proteins and then estimated the nonsynonymous (d(N)) and synonymous (d(S)) substitution rates for the regions flanking the glutamine tandem repeats and the proteins containing them. The results indicated that most of the proteins containing polyglutamine (polyQ) tracts of four or more glutamines have undergone purifying selection, and that the purifying selection for the regions flanking the repeats is weaker. Additionally, we observed that the conserved repeats were under stronger selection constraints than the nonconserved repeats. Interestingly, we found that there was a higher level of purifying selection for the regions flanking the polyQ tracts encoded by pure CAG codons compared with those encoded by mixed codons. Based on our findings, we propose that selection has played a more important role than was previously speculated in constraining the expansion of polyQ tracts encoded by pure codons.
Pubmed ID: 22848438
Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.
Collection of genome databases for vertebrates and other eukaryotic species with DNA and protein sequence search capabilities. Used to automatically annotate genome, integrate this annotation with other available biological data and make data publicly available via web. Ensembl tools include BLAST, BLAT, BioMart and the Variant Effect Predictor (VEP) for all supported species.
View all literature mentionsSoftware package as multiple alignment program for amino acid or nucleotide sequences. Can align up to 500 sequences or maximum file size of 1 MB. First version of MAFFT used algorithm based on progressive alignment, in which sequences were clustered with help of Fast Fourier Transform. Subsequent versions have added other algorithms and modes of operation, including options for faster alignment of large numbers of sequences, higher accuracy alignments, alignment of non-coding RNA sequences, and addition of new sequences to existing alignments.
View all literature mentionsPackage of programs for phylogenetic analyses of DNA or protein sequences using maximum likelihood. PAML estimates parameters and tests hypotheses to study the evolutionary process from a phylogenetic tree.
View all literature mentions