An evolutionarily conserved mechanism for controlling the efficiency of protein translation.
Recent years have seen intensive progress in measuring protein translation. However, the contributions of coding sequences to the efficiency of the process remain unclear. Here, we identify a universally conserved profile of translation efficiency along mRNAs computed based on adaptation between coding sequences and the tRNA pool. In this profile, the first approximately 30-50 codons are, on average, translated with a low efficiency. Additionally, in eukaryotes, the last approximately 50 codons show the highest efficiency over the full coding sequence. The profile accurately predicts position-dependent ribosomal density along yeast genes. These data suggest that translation speed and, as a consequence, ribosomal density are encoded by coding sequences and the tRNA pool. We suggest that the slow "ramp" at the beginning of mRNAs serves as a late stage of translation initiation, forming an optimal and robust means to reduce ribosomal traffic jams, thus minimizing the cost of protein expression.
Tuller
Tamir
T
Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
Carmi
Asaf
A
Vestsigian
Kalin
K
Navon
Sivan
S
Dorfan
Yuval
Y
Zaborske
John
J
Pan
Tao
T
Dahan
Orna
O
Furman
Itay
I
Pilpel
Yitzhak
Y
D005075:Biological Evolution; D003062:Codon / Q000378:metabolism*; D014176:Protein Biosynthesis; D012343:RNA, Transfer / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D012641:Selection, Genetic
D003062:Codon; D012343:RNA, Transfer