Abstract
Expansion of the genetic code with nonstandard amino acids (nsAAs) has enabled biosynthesis of proteins with diverse new chemistries. However, this technology has been largely restricted to proteins containing a single or few nsAA instances. Here we describe an in vivo evolution approach in a genomically recoded Escherichia coli strain for the selection of orthogonal translation systems capable of multi-site nsAA incorporation. We evolved chromosomal aminoacyl-tRNA synthetases (aaRSs) with up to 25-fold increased protein production for p-acetyl-L-phenylalanine and p-azido-L-phenylalanine (pAzF). We also evolved aaRSs with tunable specificities for 14 nsAAs, including an enzyme that efficiently charges pAzF while excluding 237 other nsAAs. These variants enabled production of elastin-like-polypeptides with 30 nsAA residues at high yields (â 1/450 mg/L) and high accuracy of incorporation (>95%). This approach to aaRS evolution should accelerate and expand our ability to produce functionalized proteins and sequence-defined polymers with diverse chemistries.
Original language | American English |
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Pages (from-to) | 1272-1279 |
Number of pages | 8 |
Journal | Nature biotechnology |
Volume | 33 |
Issue number | 12 |
DOIs | |
State | Published - 1 Dec 2015 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Applied Microbiology and Biotechnology
- Bioengineering
- Molecular Medicine
- Biotechnology
- Biomedical Engineering