AUG codons at the beginning of protein coding sequences are frequent in eukaryotic mRNAs with a suboptimal start codon context.
BACKGROUND
The translation start site plays an important role in the control of translation efficiency of eukaryotic mRNAs. However, mRNAs with a suboptimal context of start AUG codon are relatively abundant. It is likely that at least some mRNAs with suboptimal start codon context contain the other signals providing additional information for efficient AUG recognition.


RESULTS
Frequency of AUG codons at the beginning of the coding part of eukaryotic mRNAs was analyzed in relation to the context of translation start codon. It was found that the observed downstream AUG content in the mRNAs with optimal start codon context was close to the expected value, whereas it was significantly higher in the mRNAs with a suboptimal context. It is likely that downstream AUG codons can often be utilized as additional start sites to increase translation rate of mRNAs with a suboptimal context of the annotated start codon and many eukaryotic proteins can be characterized by some N-end heterogeneity.
Kochetov
Alex V
AV
Institute of Cytology and Genetics Lavrentieva 10, Novosibirsk 630090 Russia. ak@bionet.nsc.ru
D000225:Adenine; D000818:Animals; D001181:Arthropods; D001483:Base Sequence; D001717:Birds; D002874:Chromosome Mapping / Q000379:methods*; D018387:Codon, Initiator / Q000235:genetics*; D005057:Eukaryotic Cells; D005787:Gene Frequency / Q000235:genetics; D014644:Genetic Variation / Q000235:genetics; D006147:Guanine; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D010442:Peptide Chain Initiation, Translational / Q000235:genetics*; D011506:Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*; D017423:Sequence Analysis, RNA / Q000379:methods*; D013045:Species Specificity; D018911:Trinucleotide Repeats / Q000235:genetics*; D014498:Uracil
D018387:Codon, Initiator; D011506:Proteins; D012333:RNA, Messenger; D014498:Uracil; D006147:Guanine; D000225:Adenine