Computational identification of the selenocysteine tRNA (tRNASec) in genomes
Fig 5
The discriminator base G73 in tRNASec.
Sequence logos [53] of the 3’ end of tRNASec candidates from the three domains of life. The subsequences include the AT-stem, starting at position 61 of tRNA (numbering based on [35]) and extends further into the 3’ region of the gene. The residue in position 73 (the discriminator base) shows a strongly conserved G (guanine). (A) 9/4 fold tRNA cloverleaf structure indicating the 13 base pairs acceptor plus T-arm sequence used in the logos. (B) Bacteria, 2316 sequences; (C) archaea, 20 sequences; (D) eukaryota, 562 sequences; (E) bacterial 7/5 fold tRNASec candidates, including 47 sequences with a shorter 12 bp AT-stem. tRNAs have a poly-T motif in the 3’ region as the transcription termination signal [54], here only visible in archaea because of the low number of sequences. Only the top scoring candidate in each genome were used to generate the logos.