Synonymous Permutation Reveals Selection for Less Out-of-Frame Stop Codons
One important source of premature stop codons is processivity error.Although Nonsense Mediated Decay (NMD) could degrade transcripts that contain a premature stop codon, it has a fitness cost.Thus, it is commonly assumed that it is advantageous for genes to stop early after a frameshift.However, we didnt identify any pattern for excessive Out-of-flame Stop Codons (OSC) in S.cerevisiae.We shuffled the synonymous codons in genes without changing codon preference and amino acid sequence and found fewer stop codons were selected for in +1 reading frame, while no significant selection force was detected in-1 reading flame.Moreover, we checked when the first OSC appears;it is shown that there is also a selection force to avoid its early appearance.Hereby, with the support of some experimental result from another study, we raise a new hypothesis for the cost of OSC: it is more advantages to move on translating instead of truncating the peptide because the former might still to give rise to some functional products, while the latter could not.In general, the relative fitness cost of losing the possible functional products is higher than the possible costs of degrading the non-functional products.
synonymous codon permutation frameshift premature stop codon
Jingrui Zhong Nanyan Zhu
Tsinghua University Tsinghua University, Haidian District Beijing, China, 100089 Sichuan University APT 5-5, Nanan District Chongqing, China, 400061
国际会议
成都
英文
14-18
2018-03-12（万方平台首次上网日期，不代表论文的发表时间）