Genomically recoded organisms lacking release factor 1 (RF1) and engineered to express a heterologous RNA polymerase
Disclosed are methods, systems, components, and compositions related to genomically recoded and engineered organisms. The disclosed genomically recoded and engineered organisms may be used to prepare extracts for use in platforms and methods for preparing sequence defined biopolymers in vitro. In particular, the methods, systems, components, and compositions relate to genomically recoded and engineered organisms comprising a strain deficient in release factor 1 (RF-1) or a genetic homolog thereof, wherein the genomically recoded organisms have been engineered to express a heterologous RNA polymerase that may be utilized to express a target protein from a transcription template comprising a promoter for the heterologous RNA polymerase, such as bacteriophage T7 RNA polymerase.
1. A genomically recoded organism lacking release factor 1 (RF1) and engineered to express a heterologous RNA polymerase, wherein the heterologous RNA polymerase is a variant bacteriophage T7 RNA polymerase that includes a substitution that replaces a basic amino acid selected from K172 and R173 with a non-basic amino acid and/or that includes a substitution that replaces a basic amino acid selected from K179 and K180 with a non-basic amino acid.
2. The organism of claim 1 , wherein the organism is a strain of E. coli.
3. The organism of claim 1 , wherein the heterologous RNA polymerase is expressed via a promoter selected from ptac1 and lpp5.
4. The organism of claim 1 , wherein the organism is derived from a C321 strain of E. coli.
5. The organism of claim 1 , wherein the organism further comprises an orthogonal translation system component that is expressed off a plasmid or that is expressed from the genome of the organism.
6. The organism of claim 5 , wherein the orthogonal translation system component is an orthogonal tRNA or an aminoacyl tRNA synthetase.
7. The organism of claim 1 , wherein the organism comprises one or more additional genomic modifications that enhance protein synthesis yields and incorporation of multiple identical unnatural amino acids when the organism is utilized to prepare a cell-free extract for protein synthesis.
8. The organism of claim 1 , wherein the organism expresses one or more positive effector genes that augment the function of polypeptide synthesis via a plasmid or genomic integration.
9. The organism of claim 8 , wherein the positive effector gene encodes a chaperone protein.
10. The organism of claim 8 , wherein the positive effector gene is DsbC.
11. A platform for preparing a sequence defined biopolymer or protein in vitro, the platform comprising a cellular extract from the organism of claim 1 .
12. The platform of claim 7 , wherein the defined biopolymer or protein synthesized in the platform has unnatural amino acids.
13. The platform of claim 7 , wherein the defined biopolymer or protein synthesized in the platform has at least 10 unnatural amino acids.
14. A method for performing cell-free protein synthesis of a target protein comprising one or more unnatural amino acids, the method comprising expressing a mRNA encoding the target protein in the platform of claim 11 .
15. A genomically recoded organism lacking release factor 1 (RF1) and engineered to express a heterologous RNA polymerase, wherein the heterologous RNA polymerase is inserted at the asl locus of the organism's genome.
16. The organism of claim 15 , wherein the organism is a strain of E. coli.
17. The organism of claim 15 , wherein the heterologous RNA polymerase is expressed via a promoter selected from ptac1 and lpp5.
18. The organism of claim 15 , wherein the organism is derived from a C321 strain of E. coli.
19. A platform for preparing a sequence defined biopolymer or protein in vitro, the platform comprising a cellular extract from the organism of claim 15 .
20. A method for performing cell-free protein synthesis of a target protein comprising one or more unnatural amino acids, the method comprising expressing a mRNA encoding the target protein in the platform of claim 19 .