Table 7.
Preferential conservation of uAUGs in yeast orthologous 5′-UTRs
| Trinucleotide | Conserved triplets (%) | Non-conserved triplets (%) |
|---|---|---|
| AUG | 30 | 70 |
| AUG (5′-UTR<stop) | 28 | 72 |
| AUG (5′-UTR<stop + cDNA) | 36 | 64 |
| AGU | 9 | 91 |
| GUA | 7 | 93 |
| GAU | 9 | 91 |
| UAG | 10 | 90 |
| UGA | 10 | 90 |
Triplets were considered when present in the aligned sequences from all four yeast species. The AUG data set consisted of alignments of genomic sequences located upstream (50 nt) of sAUGs. The 5′-UTR<stop dataset consisted of the respective sequences containing in-frame stop codons. The AUG(5′-UTR< stop + cDNA) dataset consisted of genomic alignments of 5′-UTR<stop sets that matched 5′-UTRs of the available of yeast cDNA sequences. Fisher's exact test for the fraction of conserved AUG triplets versus the fraction of conserved AGU/GUA/GAU/UAG/UGA triplets produced highly significant results (P < 10−13) for each of the three datasets. The shuffled triplet frequencies are shown for genomic sequences located upstream of sAUGs codons of yeast genes, this corresponds to the first row of the table (the AUG dataset).