Genetic Code Expansion

The genetic code for all life is based upon four nucleotides, 64 codons, and 20 amino acids. Yet in the past two decades, biologists have expanded the genetic code by redirecting specific codons to encode amino acids beyond the 20 standard amino acids.

Expanding the Genetic Code

In protein translation, an aminoacyl-tRNA synthetase (aaRS) loads its cognate tRNA with a specific amino acid. Then, the tRNA is pulled into the ribosome and if the anticodon on the tRNA can bind to the mRNA (hence, the anticodon is complementary to the codon), the amino acid from the tRNA is incorporated into the growing peptide chain.

To expand the genetic code, modified tRNAs, codons, and tRNA synthetases are introduced into the cell on plasmids and the new amino acid is introduced in the media. Generally, you will need two plasmids, as depicted in the figure below:

1. A plasmid expressing the tRNA and its cognate aminoacyl-tRNA-synthetase (aaRS) that has been evolved to incorporate non-canonical amino acids (ncAAs).

2. A plasmid containing the gene of interest with the modified codon (typically the amber codon) that is recognized by the cognate charged tRNA.

3. Once these plasmids have been introduced in the cells, the non-canonical amino acid can be incorporated using the existing protein translation machinery.

To expand the genetic code, 4 major changes to the standard translation machinery are needed in order to incorporate a non-canonical amino acid into the protein of interest:

1. The non-canonical amino acid, which is generally introduced in the media.
2. A new codon to be allocated to the new amino acid. Because there are no free codons, this can be challenging. In E.coli, the rarest codon is the amber stop codon (UAG) and thus this codon is often used. The gene of interest can be expressed from a plasmid containing a UAG codon at the place where the new amino acid would be incorporated. Other options, such a 4-base pair codons, have also been utilized.
3. A tRNA that recognizes this codon.
4. An aminoacyl-tRNA synthetase to load the new amino acid onto the tRNA. The tRNA and synthetase are called an orthogonal set, because they should not crosstalk with the endogenous tRNA and synthetase sets. Many of these sets are derived from M. jannaschii, M. barkeri, or E.coli and can be mutated and screened through directed evolution to charge the tRNA with a different amino acid. They are typically expressed from a single plasmid, with multiple copies of the tRNA.

Applications

By making small changes in selected amino acids within a protein, any alterations in structure or function in the protein can be observed. The introduced amino acid can also be used to intentionally change the activity of a protein (e.g. converting a DNA binding protein to a DNA cleaving enzyme) or to regulate the activity of a protein so that it is responsive to specific stimuli, such as light. On a broader scale, the expanded genetic code can help us understand and evolve proteins for various purposes from therapeutics to biopolymers.

Tips for Success

Before beginning to reprogram the genetic code, there are several things to consider. If you are working off of a previously established protocol, make sure to match the growth medium, ncAA concentration, and the cell lines used previously.

Remember that the orthogonal pairs of synthetase and tRNA that work for one organism may not work for another. The orthogonal synthetase must aminoacylate only the orthogonal tRNA, and not endogenous ones. Endogenous synthetases cannot aminoacylate the orthogonal tRNA. And the orthogonal tRNA has to bind to an unallocated codon. Therefore many controls must be used to make sure that these conditions are true. Always express first with a control reporter gene – GFP for E. coli or mCherry-GFP for mammalian cells. You should also express the protein with and without the ncAA in the media to make sure that the full length protein is only made when the ncAA is included.

Browse Synthetase Plasmids

The table below highlights plasmids that contain aminoacyl tRNA synthetase for use in E.coli and Mammalian Cells. Many of the plasmids also contain one or more copies of the cognate tRNA gene.

	ID	Plasmid	Synthetase	Origin	ncAA	Expression	Codon	PI
	73546	pEvol-pAzFRS.2.t1	pAzFRS.2.t1	E. coli	p-azido-l-phenylalanine (pAzF)	Bacterial	TAG	Farren Isaacs
	68292	SepOTSλ	SepRS9	E. coli	Sep	Bacterial	TAG	Jesse Rinehart
	50832	pAcBac1.tR4-MbPyl	PylRS	M. barkeri	variety of unnatural amino acids	Mammalian	TAG	Peter Schultz
	49086	pDULE-ABK	PylRS	M. barkeri	aliphatic diazirine amino acid	Bacerial, Mammalian	TAG	Peter Schultz
	48696	pANAP	AnapRS	E. coli	fluorescent AA, Anap	Mammalian	TAG	Peter Schultz
	48215	pULTRA-CNF	tyrosyl-tRNA synthetase	M. jannaschii	para-cyanophenylalanine (pCNPhe)	Bacterial	TAG	Peter Schultz
	31190	pEVOL-pBpF	p-benzoylphenylalanine RS	M. jannaschii	p-benzoyl-l-phenylalanine	Bacterial	TAG	Peter Schultz
	31186	pEVOL-pAzF	p-azidohenylalanine RS	M. jannaschii	p-azido-l-phenylalanine	Bacterial	TAG	Peter Schultz
	127411	pEVOL-pylT-N346A/C348A	PylRS	M. mazei	mono-substituted phenylalanine derivatives and tyrosinyl ethers	Bacterial	TAG	Wenshe Liu
	122650	Mm-PylRS-AF/Pyl-tRNACUA	PylRS	M. mazei	trans-cyclooct- 2-ene-lysine (TCOK)	Mammalian	TAG	Howard Hang
	105830	pNEU-hMbPylRS-4xU6M15	PylRS	M. barkeri	Pyl-like click amino acids, tRNA M15	Mammalian	TAG	Irene Coin
	105829	pIRE4-Azi	Azi-tRNA synthetase (EAziRS)		p-Azido-phenylalanine (Azi)	Mammalian	TAG	Irene Coin
	91706	pCMV-MbPylRS(DiZPK)	PylRS	M. barkeri	photocrosslinkers DiZPK, DiZSeK, or DiZHSeC	Mammalian	TAG	P. Chen
	89189	pMaRSC	methionyl-tRNA synthetase (L274GMmMetRS)	M. musculus	azidonorleucine (Anl)	Mammalian	ATG	David Tirrell
	73547	pEvol-pAzFRS.1.t1	pAzFRS.1.t1	E. coli	p-azido-l-phenylalanine (pAzF)	Bacterial	TAG	Farren Isaacs
	63177	pMarsL274G	methionyl-tRNA synthetase (L274GMmMetRS)	M. musculus	azidonorleucine (Anl)	Mammalian	ATG	David Tirrell
	50831	pAcBac2.tR4-OMeYRS/GFP*	tyrosyl-tRNA synthetase	E. coli	various unnatural amino acids	Mammalian	TAG	Peter Schultz
	173897	SepRS(2)/pSertRNA(B4)/EF-Sep	aminoacyl-tRNA synthetase	M. maripaludis	phosphoserine	Bacterial		Jason W Chin
	137976	pEVOL-AckRS	PylRS	M. mazei	AzHeK	Bacterial	TAG	Wenshe Liu
	126035	pEVOL-ABK	PylRS	M. barkeri	3’-azibutyl-N-carbamoyl-lysine (AbK)	Bacterial	TAG	Andrea Musacchio
	104069	pTECH-chAcK3RS(IPYE)	AcK3RS	Chimeric	Nε-acetyl-L-lysine	Bacterial	TAG	David Liu
	99222	pTECH-chPylRS(IPYE)	PylRS	Chimeric	p-iodo-L-phenylalanine	Bacterial	TAG	Dieter Soll
	91705	pSupAR-MbPylRS(DiZPK)	PylRS	M. barkeri	photocrosslinkers DiZPK, DiZSeK, or DiZHSeC	Bacterial	TAG	P. Chen
	85495	pDule2-pCNF	para-cyanophenylalanine synthetase	M. jannaschii	azidoPhenylalanine	Bacterial	TAG	Ryan Mehl
	85494	pDule-pCNF	para-cyanophenylalanine synthetase	M. jannaschii	azidoPhenylalanine	Bacterial	TAG	Ryan Mehl
	85484	pDule-tfmF A65V S158A	tri-fluoromethyl-phenylalanine synthetase	M. jannaschii	family of [19]F-UAAs	Bacterial	TAG	Ryan Mehl
	82417	pUltra-sY	sY-specific aaRS	M. jannaschii	sulfotyrosine (sY)	Bacterial, Plant	TAG	Chang Liu
	73545	pEvol-pAcFRS.1.t1	pAcFRS.1.t1	E. coli	p-acetyl-l-phenylalanine (pAcF)	Bacterial	TAG	Farren Isaacs
	73544	pEvol-pAcFRS.2.t1	pAcFRS.2.t1	E. coli	p-acetyl-l-phenylalanine (pAcF)	Bacterial	TAG	Farren Isaacs
	64915	pMAH-POLY	tyrosyl-tRNA synthetase	E. coli	pBof	Mammalian	TAG	Huiwang Ai
	51401	pAM1	NLL-MetRS	E. coli	azi-donorleucine (Anl)	Bacterial	ATG	David Tirrell
	196486	pcPylRS(Y384F Y306A)	PylRS(Y384F Y306A)	M. mazei	Z-Lys or Azido-Z-Lys	Mammalian	TAG	Kensaku Sakamoto
	193250	pMV361_MjTyrRS	tyrosyl-tRNA synthetase	M. jannaschii		Bacterial	TAG	Peter Schultz
	182884	AzoRS-4	tyrosyl-tRNA synthetase	M. jannaschii	azobenzene-bearing uAAs	Bacterial	TAG	Miriam Amiram
	182882	Mut2-RS	tyrosyl-tRNA synthetase	M. jannaschii	4-propargyloxy-l-phenylalanine (pPR)	Bacterial	TAG	Miriam Amiram
	182881	Mut1-RS	tyrosyl-tRNA synthetase	M. jannaschii	4-propargyloxy-l-phenylalanine (pPR)	Bacterial	TAG	Miriam Amiram
	182653	pcDNA3.1(+)_U6 tRNAPyl_CMV NESPylRS(AF)_IRES_eRF1(E55D)-HA	Y306A/Y384F (AF) pyrrolysine (Pyl) tRNA synthetase	M. mazei		Mammalian	TAG	Ivana Nikic-Spiegel
	182652	pcDNA3.1(+)_4x(U6 tRNA M15)_CMV NESPylRS(AF)	Y306A/Y384F (AF) pyrrolysine (Pyl) tRNA synthetase	M. mazei		Mammalian	TAG	Ivana Nikic-Spiegel
	182537	pEVOL-MmAcKRS1-PylTUUA	PylRS	M. mazei		Bacterial	TAA	Wenshe Liu
	182287	pcDNA3.1(+)_U6 tRNAPyl_CMV NESPylRS(AF)	Y306A/Y384F (AF) pyrrolysine (Pyl) tRNA synthetase	M. mazei		Mammalian	TAG	Ivana Nikic-Spiegel
	177311	pRSF-G1TFAKRS		Methanogenic archaeon ISO4-G1	N6-(trifluoroacetyl)-L-lysine (TFA-Lys)	Bacterial	TAG	Thomas Huber
	177310	pRSF-G1(7FTrp)RS	PylRS	Methanogenic archaeon ISO4-G1	7-Fluoro-L-Tryptophan (7FTrp)	Bacterial	TAG	Thomas Huber
	174890	pAS_8xMmaPylT_EF1_FLAG-MmaPylRS	PylRS	M. mazei		Mammalian	TAG	Simon Elsaesser
	174719	pRSF-G1pCNPRS	G1pCNPRS	Methanogenic archaeon ISO4-G1	L-3-(2-cyano-5-pyridyl)alanine (pCNP)	Bacterial	TAG	Thomas Huber
	174718	pRSF-G1mCNPRS	G1mCNPRS	Methanogenic archaeon ISO4-G1	L-3-(2-cyano-4-pyridyl)alanine (mCNP)	Bacterial	TAG	Thomas Huber
	174516	pMB1_1R26PylRS(CbzK)_AfTyrRS(p-I-Phe)_AlvtRNA-ΔNPyl(8)(CGA)_AftRNA-Tyr(A01)(CUA)	1R26PylRS and AfTyrRS		CbzK and p-I-Phe	Bacterial	TCG and TAG	Jason W Chin
	174515	pMB1_MmPylRS_MmtRNA-Pyl-opt(UGA)	PylRS	M. mazei		Bacterial	TGA	Jason W Chin
	174101	pAcBac1.tR4-AcdRS82	Acridone 82 tRNA synthetase	M. barkeri	acridone	Mammalian		Ryan Mehl
	174100	pDule2-Acd82	Acridone 82 tRNA synthetase	M. barkeri	acridone	Bacterial	TAG	Ryan Mehl
	174099	pDule-Acd82	Acridone 82 tRNA synthetase	M. barkeri	acridone	Bacterial	TAG	Ryan Mehl
	174081	pAcBac1-NES-Flag-R2-84-MbRS Tetrazine3.0	NES-Flag-R2-84 tRNA synthetase	M. barkeri	Tetrazine 3.0	Mammalian		Ryan Mehl
	174080	pDule-Tet3.0	Tet3.0 tRNA synthetase	M. barkeri	Tetrazine 3.0	Bacterial	TAG	Ryan Mehl
	174079	pDule2-3-nitroTyrosine (A7)	3NY (A7) synthetase	M. jannaschii	3-nitroTyrosine	Bacterial	TAG	Ryan Mehl
	174078	pDule-3-nitroTyrosine (A7)	3NY (A7) synthetase	M. jannaschii	3-nitroTyrosine	Bacterial	TAG	Ryan Mehl
	172482	pEVOL-pylT-AznLRS	AznLRS	M. mazei	azidonorleucine	Bacterial	TAG	Wenshe Liu
	164196	pCMV-MfBulKRS (human-opti)	BulKRS	M. flavescens	acetyl-lysine	Mammalian		Tao Liu
	164195	pCMV-MtAcKRS (human-opti)	AcKRS	M. thermophila	acetyl-lysine	Mammalian		Tao Liu
	164081	pCMV-MfPylRS (human-opti)	PylRS	M. flavescens	acetyl-lysine	Mammalian		Tao Liu
	164080	pCMV-MtPylRS (human-opti)	PylRS	M. thermophila	acetyl-lysine	Mammalian		Tao Liu
	163916	pXPR-SF61	SF5Phe tRNA synthetase		para-Pentafluorosulfanyl-Phenylalanine	Bacterial	TAG	Thomas Huber
	163915	pRSF-ChPylTMSK	ChPylTMSK		N6-(((Trimethylsilyl)methoxy)carbonyl)-L-lysine (TMSK)	Bacterial	TAG	Thomas Huber
	160378	pDule2-Mb haloTyrRS C6	C6 HaloTyrosine tRNA synthatase	M. barkeri	Halotyrosine Amino Acids	Bacterial	TAG	Ryan Mehl
	160377	pDule-Mb haloTyrRS C6	C6 HaloTyrosine tRNA synthatase	M. barkeri	Halotyrosine Amino Acids	Bacterial	TAG	Ryan Mehl
	160089	pPaGE Pyl TAG FliC T248TAG	PylRS	M. mazei		Bacterial	TAG	Lital Alfonta
	160041	pRaGE Pyl TAG GFP Y35TAG	PylRS	M. mazei		Bacterial	TAG	Lital Alfonta
	157925	pMAH-POLY-eRF1(E55D)	POLY-eRF1(E55D)	E. coli	para-substituted phenylalanine analogs	Mammalian	TAG	Huiwang Ai
	154774	pAS_4xU6-PylT M15 (UUA) FLAG-Mma PylRS	PylRS	M. mazei		Mammalian	TAA	Simon Elsaesser
	154773	pAS_4xhybPylT A41AA C55A FLAG-G1 PylRS Y125A	G1 PylRS Y125A	Methanogenic archaeon ISO4-G1		Mammalian	TAG	Simon Elsaesser
	154769	pAS_4xG1 PylT FLAG-G1 PylRS Y125A	G1 PylRS Y125A	Methanogenic archaeon ISO4-G1		Mammalian	TAG	Simon Elsaesser
	154768	pAS_4xG1 PylT FLAG-G1 PylRS	G1 PylRS	Methanogenic archaeon ISO4-G1		Mammalian	TAG	Simon Elsaesser
	154764	pAS_FLAG-Mx1201 PylRS	PylRS	Methanomethylophilus alvus Mx1201		Mammalian	TAG	Simon Elsaesser
	154763	pAS_FLAG-G1 PylRS	G1 PylRS	Methanogenic archaeon ISO4-G1		Mammalian	TAG	Simon Elsaesser
	154762	pAS_FLAG-Mma PylRS	PylRS	M. mazei		Mammalian	TAG	Simon Elsaesser
	153558	pMAH-EcaYRS	EcaYRS	E. coli	3-aminotyrosine	Mammalian		Huiwang Ai
	153557	pEvol-MjaYRS	MJaYRS	M. jannaschii	3-aminotyrosine	Bacterial	TAG	Huiwang Ai
	141174	pAcBac1-haloTyrRS C6	C6 HaloTyrosine tRNA synthatase	E. coli		Mammalian		Ryan Mehl
	141173	pAcBac1-3nitroY-A7-RS	A7 3nY tRNA synthetase	M. barkeri		Mammalian		Ryan Mehl
	140023	pAS_4xMma PylT_FLAG-Mma PylRS AF	PylRS AF	M. mazei		Mammalian	TAG	Simon Elsaesser
	140022	pAS_4xMma PylT_FLAG-PcKRS	PcKRS	M. barkeri	photocaged-lysine	Mammalian	TAG	Simon Elsaesser
	140021	pAS_4xMma PylT_FLAG-AcKRS	AcKRS	M. mazei	acetyl-lysine	Mammalian	TAG	Simon Elsaesser
	140020	pAS_4xMma PylT_FLAG-AbKRS-chIPYE	chimeric PylRS	Chimeric	photo-crosslinking-lysine	Mammalian	TAG	Simon Elsaesser
	140019	pAS_4xEcoLeuT(CUA)_AnapRS	AnapRS	E. coli	azido-phenylalanine	Mammalian	TAG	Simon Elsaesser
	140018	pAS_4xBstTyrT(CUA)_EcoTyrRS-FLAG	tyrosyl-tRNA synthetase	E. coli		Mammalian	TAG	Simon Elsaesser
	140014	pAS_4xMx PylT C41CA_FLAG_Mx PylRS YA	PylRS	Methanomethylophilus alvus Mx1201		Mammalian	TAG	Simon Elsaesser
	140013	pAS_4xMx PylT C41CA_FLAG_Mx PylRS	PylRS	Methanomethylophilus alvus Mx1201		Mammalian	TAG	Simon Elsaesser
	140012	pAS_4xMx PylT_FLAG-Mx PylRS YA	PylRS YA	Methanomethylophilus alvus Mx1201		Mammalian	TAG	Simon Elsaesser
	140011	pAS_4xMx PylT_FLAG-Mx PylRS	PylRS	Methanomethylophilus alvus Mx1201	CpK	Mammalian	TAG	Simon Elsaesser
	140009	pAS_4xMma PylT_FLAG-Mma PylRS	PylRS	M. mazei	CpK, AbK	Mammalian	TAG	Simon Elsaesser
	137908	PylRS-AS	PylRS	M. mazei	fluorophenylalanine derivatives	Bacterial	TAG	Wenshe Liu
	127445	pEDF-PhdRS	PylRS N346A-C348A	M. mazei		Bacterial		Wenshe Liu
	127415	pEVOL-AcKRS-CloDF	PylRS	M. mazei	acyl-lysine derivatives	Bacterial		Wenshe Liu
	113645	pRF0G-IodoY	iodotyrosine tRNA synthetase	M. jannaschii	iodotyrosine	Bacterial	TAG	Jeffrey Barrick
	113644	pRF0G-Tyr	tyrosyl-tRNA synthetase	M. jannaschii	tyrosine	Bacterial	TAG	Jeffrey Barrick
	104073	pTECH-MmPylRS(IPYE)	PylRS	M. mazei	m-iodo-L-phenylalanine	Bacterial	TAG	David Liu
	104072	pTECH-MbPylRS(IPYE)	PylRS	M. barkeri	m-iodo-L-phenylalanine	Bacterial	TAG	David Liu
	104071	pTECH-MmAcK3RS(IPYE)	AcK3RS	M. mazei	Nε-acetyl-L-lysine	Bacterial	TAG	David Liu
	104070	pTECH-MbAcK3RS(IPYE)	AcK3RS	M. barkeri	Nε-acetyl-L-lysine	Bacterial	TAG	David Liu
	92048	gCOTS-pyl	PylRS	M. mazei		Cyanobacterial	TAG	Lital Alfonta
	92047	pCOTS-pyl-GFP(35TAG)	PylRS	M. mazei		Cyanobacterial	TAG	Lital Alfonta
	85503	pDule2-para-aminoPhe	pAF synthetase	M. jannaschii	para-aminoPhe	Bacterial	TAG	Ryan Mehl
	85502	pDule-para-aminoPhe	pAF synthetase	M. jannaschii	para-aminoPhe	Bacterial	TAG	Ryan Mehl
	85501	pDule2-IBBN (G2)	IBBN (G2) synthetase	M. jannaschii	4-(2′-bromoisobutyramido)-phenylalanine (IBBN) and structurally analogous amino acids	Bacterial	TAG	Ryan Mehl
	85500	pDule-IBBN (G2)	IBBN (G2) synthetase	M. jannaschii	4-(2′-bromoisobutyramido)-phenylalanine (IBBN) and structurally analogous amino acids	Bacterial	TAG	Ryan Mehl
	85499	pDule2-3-nitroTyrosine (5B)	3NY (5B) synthetase	M. jannaschii	3-nitroTyrosine	Bacterial	TAG	Ryan Mehl
	85498	pDule-3-nitroTyrosine (5B)	3NY (5B) synthetase	M. jannaschii	3-nitroTyrosine	Bacterial	TAG	Ryan Mehl
	85497	pDule2-Tet2.0	Tetrazine2.0 tRNA synthetas	M. jannaschii	Tetrazine 2.0	Bacterial	TAG	Ryan Mehl
	85496	pDule-Tet2.0	Tetrazine2.0 tRNA synthetase	M. jannaschii	Tetrazine 2.0	Bacterial	TAG	Ryan Mehl
	71404	pMAH2-CageCys	leucyl-tRNA-synthetase	E. coli	photocaged cysteine	Mammalian	TAG	Huiwang Ai
	71403	pCMV-DnpK	PylRS	M. barkeri	N6‐(2‐(2,4‐dinitrophenyl)acetyl)lysine (DnpK)	Bacterial, Mammalian	TAG	Huiwang Ai
	62599	pKPY197	phenylalanyl-tRNA synthetase (CePheRS)	C.elegans	p-azido-L-phenylalanine (Azf)	C. elegans	ATG	David Tirrell
	62598	pKPY514	phenylalanyl-tRNA synthetase subunit	E. coli	p-azido-L-phenylalanine (Azf)	C. elegans	ATG	David Tirrell
	188537	pSerOTS-C1* (V70)	SerRS	M. maripaludis	Phosphoserine	Bacterial	TAG	Jesse Rinehart

Browse Strains

The table below highlights bacteria strains that have been modified to enhance non-standard amino acid incorporation.

	ID	Strain	Description	PI
	68306	C321.ΔA	all TAG sites changes to UAG, RF1 function removed, deletion of SerB to maintain sufficient levels of Sep in the cytoplasm for protein synthesis. Also see strain 192872.	Jesse Rinehart
	49018	C321.ΔA.exp	all TAG sites changes to UAG, RF1 function removed, MutS restored so decreased mutation rate	George Church
	48998	C321.ΔA	all TAG sites changes to UAG, RF1 function removed	George Church
	87359	C321.∆A.opt	all TAG sites changes to UAG, RF1 function removed, improved doubling time.	George Church
	174514	Syn61Δ3(ev5)	No TCG, TCA, or TAG codons. Deletion of serT, serU, and prfA genes	Jason W Chin
	73581	C321.deltaA (Isaacs lab)	all TAG sites changes to UAG, RF1 function removed	Farren Isaacs
	48999	C321	all TAG sites changes to UAG	George Church
	192872	rEcoli XpS	All 321 UAG codons changed to UAA. mutS+, λ-, ΔybhB-bioAB, ΔprfA, ΔserB mutations for improved yield and growth	Jesse Rinehart
	174513	Syn61	No TCG, TCA, or TAG codons in all open reading frames	Jason W Chin
	98565	C321.ΔClpS.Ub-UAG-sfGFP	all TAG sites changes to UAG, RF1 function removed, ClpS inactivated, with Ubiquitin-UAG-sfGFP reporter	George Church
	98564	C321.Ub-UAG-sfGFP	all TAG sites changes to UAG, RF1 function removed, with Ubiquitin-UAG-sfGFP reporter	George Church
	69495	rEc.13.delA	13 amber sites changed to TAA, RF1 function removed	Michael Jewett
	69493	MCJ.559	TAG sites, RF1 function removed, genomic deletions for improved incorporation	Michael Jewett

Browse Target Plasmids

The table below highlights plasmids that contain genes with modified codons for unnatural amino acid incorporation.