Codon bias at the 3'-side of the initiation codon is correlated with translation initiation efficiency in Escherichia coli.
Gene
; 263(1-2): 273-84, 2001 Jan 24.
Article
em En
| MEDLINE
| ID: mdl-11223267
ABSTRACT
The codon that follows the AUG initiation triplet (+2 codon) affects gene expression in Escherichia coli. We have extended this analysis using two model genes lacking any apparent Shine-Dalgarno sequence. Depending on the identity of the +2 codon a difference in gene expression up to 20-fold could be obtained. The effects did not correlate with the levels of intracellular pools of cognate tRNA for the +2 codon, with putative secondary mRNA structures, or with mRNA stability. However, most +2 iso-codons that were decoded by the same species of tRNA gave pairwise similar effects, suggesting that the effect on gene expression was associated with the decoding tRNA. High adenine content of the +2 codon was associated with high gene expression. Of the fourteen +2 codons that mediated the highest efficiency, all except two had an adenine as the first base of the codon. Analysis of the 3540 E. coli genes from the TransTerm database revealed that codons associated with high gene expression in the two expression systems are over-represented at the +2 position in natural genes. Codons that are associated with low gene expression are under-represented. The data suggest that evolution has favored codons at the +2 position that give high translation initiation.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Biossíntese de Proteínas
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Códon
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Códon de Iniciação
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Escherichia coli
Idioma:
En
Revista:
Gene
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Suécia