Open AccessOptimization of Translation Profiles Enhances Protein Expression and Solubility
Author(s) -
Anne-Katrin Heß,
Paul Saffert,
Klaus Liebeton,
Zoya Ignatova
Publication year - 2015
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0127039
Subject(s) - translation (biology) , codon usage bias , protein biosynthesis , protein folding , translational efficiency , coding region , eukaryotic translation , messenger rna , polysome , biology , ribosomal protein , genetics , gene , biochemistry , ribosome , rna , genome
mRNA is translated with a non-uniform speed that actively coordinates co-translational folding of protein domains. Using structure-based homology we identified the structural domains in epoxide hydrolases (EHs) and introduced slow-translating codons to delineate the translation of single domains. These changes in translation speed dramatically improved the solubility of two EHs of metagenomic origin in Escherichia coli . Conversely, the importance of transient attenuation for the folding, and consequently solubility, of EH was evidenced with a member of the EH family from Agrobacterium radiobacter , which partitions in the soluble fraction when expressed in E . coli . Synonymous substitutions of codons shaping the slow-transiting regions to fast-translating codons render this protein insoluble. Furthermore, we show that low protein yield can be enhanced by decreasing the free folding energy of the initial 5’-coding region, which can disrupt mRNA secondary structure and enhance ribosomal loading. This study provides direct experimental evidence that mRNA is not a mere messenger for translation of codons into amino acids but bears an additional layer of information for folding, solubility and expression level of the encoded protein. Furthermore, it provides a general frame on how to modulate and fine-tune gene expression of a target protein.