title: Increased levels of recombinant human proteins with the Escherichia coli strain Rosetta(DE3).
abstract: The effect of two Escherichiacoli expression strains on the production of recombinant human protein fragments was evaluated. High-throughput protein production projects, such as the Swedish Human Protein Atlas project, are dependent on high protein yield and purity. By changing strain from E. coli BL21(DE3) to E. coli Rosetta(DE3) the overall success rate of the protein production has increased dramatically. The Rosetta(DE3) strain compensates for a number of rare codons. Here, we describe how the protein expression of human gene fragments in E. coli strains BL21(DE3) and Rosetta(DE3) was evaluated in two stages. Initially a test set of 68 recombinant proteins that previously had been expressed in BL21(DE3) was retransformed and expressed in Rosetta(DE3). The test set generated very positive results with an improved expression yield and a significantly better purity of the protein product which prompted us to implement the Rosetta(DE3) strain in the high-throughput protein production. Except for analysis of protein yield and purity the sequences were also analyzed regarding number of rare codons and rare codon clusters. The content of rare codons showed to have a significant effect on the protein purity. Based on the results of this study the atlas project permanently changed expression strain to Rosetta(DE3).
authors.affiliation: School of Biotechnology, Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Hanna
authors.initials: H
authors.lastname: Tegel
authors.forename: Samuel
authors.initials: S
authors.lastname: Tourle
authors.forename: Jenny
authors.initials: J
authors.lastname: Ottosson
authors.forename: Anja
authors.initials: A
authors.lastname: Persson
mesh_terms: D003062:Codon; D030562:Databases, Protein; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D057166:High-Throughput Screening Assays / Q000379:methods*; D006801:Humans; D010446:Peptide Fragments / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D040901:Proteomics; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D003062:Codon; D010446:Peptide Fragments; D011994:Recombinant Proteins