Dosage effect of minor arginyl- and isoleucyl-tRNAs on protein synthesis in an Escherichia coli in vitro coupled transcription/translation system.
In Escherichia coli mRNA, the arginine codons AGA/AGG and the isoleucine codon AUA are rarely used with frequencies of about 0.35% and 0.41%, respectively. Six genes with a different number of these codons were expressed in an E. coli in vitro coupled transcription/translation system, which contained either tRNA prepared from E. coli cells carrying a plasmid with argU and ileX genes encoding rare tRNAs (tRNA(arg)(AGA/AGG) and tRNA(ile)(AUA)), designated codon-plus tRNA, or normal tRNA from cells lacking the plasmid. Genes having a low number of the rare codons, such as genes encoding chloramphenicol acetyltransferase and anti-gp120 single-chain Fv (artificially constructed to remove rare codons), were expressed at similar levels using with both tRNA preparations. On the other hand, the use of codon-plus tRNA increased the expression levels of genes having a relatively large number of the rare codons, including genes encoding archaeal proteins, green fluorescent protein of jelly fish origin, and a single-chain Fv of mouse origin, by about 20% higher than that using normal tRNA.
Jiang
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X
Laboratory of Molecular Biotechnology, Graduate School of Biological and Agricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
Nakano
H
H
Kigawa
T
T
Yabuki
T
T
Yokoyama
S
S
Clark
D S
DS
Yamane
T
T