Eukaryotic mRNAs encoding abundant and scarce proteins are statistically dissimilar in many structural features

It is well known that non-coding mRNA sequences are dissimilar in many stru ctural features. For individual mRNAs correlations were found for some of t hese features and their translational efficiency, However, no systematic st atistical analysis was undertaken to relate protein abundance and structura l characteristics of mRNA encoding the given protein. We have demonstrated that structural and contextual features of eukaryotic mRNAs encoding high- and low-abundant proteins differ in the 5' untranslated regions (UTR), Stat istically, 5' UTRs of low-expression mRNAs are longer, their guanine plus c ytosine content is higher, they have a less optimal context of the translat ion initiation codons of the main open reading frames and contain more freq uently upstream AUG than 5' UTRs of high-expression mRNAs, Apart from the d ifferences in 5' UTRs, high-expression mRNAs contain stronger termination s ignals. Structural features of low- and high-expression mRNAs are likely to contribute to the yield of their protein products. (C) 1998 Federation of European Biochemical Societies.