1
|
Koch NG, Budisa N. Evolution of Pyrrolysyl-tRNA Synthetase: From Methanogenesis to Genetic Code Expansion. Chem Rev 2024; 124:9580-9608. [PMID: 38953775 PMCID: PMC11363022 DOI: 10.1021/acs.chemrev.4c00031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 05/22/2024] [Accepted: 05/28/2024] [Indexed: 07/04/2024]
Abstract
Over 20 years ago, the pyrrolysine encoding translation system was discovered in specific archaea. Our Review provides an overview of how the once obscure pyrrolysyl-tRNA synthetase (PylRS) tRNA pair, originally responsible for accurately translating enzymes crucial in methanogenic metabolic pathways, laid the foundation for the burgeoning field of genetic code expansion. Our primary focus is the discussion of how to successfully engineer the PylRS to recognize new substrates and exhibit higher in vivo activity. We have compiled a comprehensive list of ncAAs incorporable with the PylRS system. Additionally, we also summarize recent successful applications of the PylRS system in creating innovative therapeutic solutions, such as new antibody-drug conjugates, advancements in vaccine modalities, and the potential production of new antimicrobials.
Collapse
Affiliation(s)
- Nikolaj G. Koch
- Department
of Chemistry, Institute of Physical Chemistry, University of Basel, 4058 Basel, Switzerland
- Department
of Biosystems Science and Engineering, ETH
Zurich, 4058 Basel, Switzerland
| | - Nediljko Budisa
- Biocatalysis
Group, Institute of Chemistry, Technische
Universität Berlin, 10623 Berlin, Germany
- Chemical
Synthetic Biology Chair, Department of Chemistry, University of Manitoba, Winnipeg MB R3T 2N2, Canada
| |
Collapse
|
2
|
Schmitt MA, Tittle JM, Fisk JD. Codon decoding by orthogonal tRNAs interrogates the in vivo preferences of unmodified adenosine in the wobble position. Front Genet 2024; 15:1386299. [PMID: 38706795 PMCID: PMC11066159 DOI: 10.3389/fgene.2024.1386299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 03/30/2024] [Indexed: 05/07/2024] Open
Abstract
The in vivo codon decoding preferences of tRNAs with an authentic adenosine residue at position 34 of the anticodon, the wobble position, are largely unexplored because very few unmodified A34 tRNA genes exist across the three domains of life. The expanded wobble rules suggest that unmodified adenosine pairs most strongly with uracil, modestly with cytosine, and weakly with guanosine and adenosine. Inosine, a modified adenosine, on the other hand, pairs strongly with both uracil and cytosine and to a lesser extent adenosine. Orthogonal pair directed sense codon reassignment experiments offer a tool with which to interrogate the translational activity of A34 tRNAs because the introduced tRNA can be engineered with any anticodon. Our fluorescence-based screen utilizes the absolute requirement of tyrosine at position 66 of superfolder GFP for autocatalytic fluorophore formation. The introduced orthogonal tRNA competes with the endogenous translation machinery to incorporate tyrosine in response to a codon typically assigned another meaning in the genetic code. We evaluated the codon reassignment efficiencies of 15 of the 16 possible orthogonal tRNAs with A34 anticodons. We examined the Sanger sequencing chromatograms for cDNAs from each of the reverse transcribed tRNAs for evidence of inosine modification. Despite several A34 tRNAs decoding closely-related C-ending codons, partial inosine modification was detected for only three species. These experiments employ a single tRNA body with a single attached amino acid to interrogate the behavior of different anticodons in the background of in vivo E. coli translation and greatly expand the set of experimental measurements of the in vivo function of A34 tRNAs in translation. For the most part, unmodified A34 tRNAs largely pair with only U3 codons as the original wobble rules suggest. In instances with GC pairs in the first two codon positions, unmodified A34 tRNAs decode the C- and G-ending codons as well as the expected U-ending codon. These observations support the "two-out-of-three" and "strong and weak" codon hypotheses.
Collapse
Affiliation(s)
| | | | - John D. Fisk
- Department of Chemistry, University of Colorado Denver, Denver, CO, United States
| |
Collapse
|
3
|
Thaenert A, Sevostyanova A, Chung CZ, Vargas-Rodriguez O, Melnikov SV, Söll D. Engineered mRNA-ribosome fusions for facile biosynthesis of selenoproteins. Proc Natl Acad Sci U S A 2024; 121:e2321700121. [PMID: 38442159 PMCID: PMC10945757 DOI: 10.1073/pnas.2321700121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Accepted: 01/31/2024] [Indexed: 03/07/2024] Open
Abstract
Ribosomes are often used in synthetic biology as a tool to produce desired proteins with enhanced properties or entirely new functions. However, repurposing ribosomes for producing designer proteins is challenging due to the limited number of engineering solutions available to alter the natural activity of these enzymes. In this study, we advance ribosome engineering by describing a novel strategy based on functional fusions of ribosomal RNA (rRNA) with messenger RNA (mRNA). Specifically, we create an mRNA-ribosome fusion called RiboU, where the 16S rRNA is covalently attached to selenocysteine insertion sequence (SECIS), a regulatory RNA element found in mRNAs encoding selenoproteins. When SECIS sequences are present in natural mRNAs, they instruct ribosomes to decode UGA codons as selenocysteine (Sec, U) codons instead of interpreting them as stop codons. This enables ribosomes to insert Sec into the growing polypeptide chain at the appropriate site. Our work demonstrates that the SECIS sequence maintains its functionality even when inserted into the ribosome structure. As a result, the engineered ribosomes RiboU interpret UAG codons as Sec codons, allowing easy and site-specific insertion of Sec in a protein of interest with no further modification to the natural machinery of protein synthesis. To validate this approach, we use RiboU ribosomes to produce three functional target selenoproteins in Escherichia coli by site-specifically inserting Sec into the proteins' active sites. Overall, our work demonstrates the feasibility of creating functional mRNA-rRNA fusions as a strategy for ribosome engineering, providing a novel tool for producing Sec-containing proteins in live bacterial cells.
Collapse
Affiliation(s)
- Anna Thaenert
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT06511
| | | | - Christina Z. Chung
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT06511
| | | | - Sergey V. Melnikov
- Biosciences Institute, Newcastle University, Newcastle upon TyneNE2 4HH, United Kingdom
- Biosciences Institute, Newcastle University Medical School, Newcastle upon TyneNE2 4HH, United Kingdom
| | - Dieter Söll
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT06511
- Department of Chemistry, Yale University, New Haven, CT06511
| |
Collapse
|
4
|
Icking LS, Riedlberger AM, Krause F, Widder J, Frederiksen A, Stockert F, Spädt M, Edel N, Armbruster D, Forlani G, Franchini S, Kaas P, Kırpat Konak BM, Krier F, Lefebvre M, Mazraeh D, Ranniger J, Gerstenecker J, Gescher P, Voigt K, Salavei P, Gensch N, Di Ventura B, Öztürk MA. iNClusive: a database collecting useful information on non-canonical amino acids and their incorporation into proteins for easier genetic code expansion implementation. Nucleic Acids Res 2024; 52:D476-D482. [PMID: 37986218 PMCID: PMC10767842 DOI: 10.1093/nar/gkad1090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 10/27/2023] [Accepted: 10/30/2023] [Indexed: 11/22/2023] Open
Abstract
The incorporation of non-canonical amino acids (ncAAs) into proteins is a powerful technique used in various research fields. Genetic code expansion (GCE) is the most common way to achieve this: a specific codon is selected to be decoded by a dedicated tRNA orthogonal to the endogenous ones. In the past 30 years, great progress has been made to obtain novel tRNA synthetases (aaRSs) accepting a variety of ncAAs with distinct physicochemical properties, to develop robust in vitro assays or approaches for codon reassignment. This sparked the use of the technique, leading to the accumulation of publications, from which gathering all relevant information can appear daunting. Here we present iNClusive (https://non-canonical-aas.biologie.uni-freiburg.de/), a manually curated, extensive repository using standardized nomenclature that provides organized information on ncAAs successfully incorporated into target proteins as verified by mass spectrometry. Since we focused on tRNA synthetase-based tRNA loading, we provide the sequence of the tRNA and aaRS used for the incorporation. Derived from more than 687 peer-reviewed publications, it currently contains 2432 entries about 466 ncAAs, 569 protein targets, 500 aaRSs and 144 tRNAs. We foresee iNClusive will encourage more researchers to experiment with ncAA incorporation thus contributing to the further development of this exciting technique.
Collapse
Affiliation(s)
- Leon-Samuel Icking
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
| | - Andreas Martin Riedlberger
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
| | - Fabian Krause
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
| | - Jonas Widder
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
| | - Anne Smedegaard Frederiksen
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
| | - Fabian Stockert
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
| | - Michael Spädt
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
| | - Nikita Edel
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
| | - Daniel Armbruster
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
- Institute of Biology II, Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104, Freiburg, Germany
| | - Giada Forlani
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
- Institute of Biology II, Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104, Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Albertstr. 19A, 79104, Freiburg, Germany
| | - Selene Franchini
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
| | - Paulina Kaas
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117, Heidelberg, Germany
| | - Büşra Merve Kırpat Konak
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
- Institute of Biology II, Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104, Freiburg, Germany
| | - Fabrice Krier
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
- Institute of Biology II, Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104, Freiburg, Germany
| | - Maïwenn Lefebvre
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
- Institute of Biology II, Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104, Freiburg, Germany
| | - Daniel Mazraeh
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
- Institute of Biology II, Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104, Freiburg, Germany
| | - Jeremy Ranniger
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
| | - Johanna Gerstenecker
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
| | - Pia Gescher
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
| | - Karsten Voigt
- Institute of Biology III, Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104, Freiburg, Germany
| | - Pavel Salavei
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
| | - Nicole Gensch
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
| | - Barbara Di Ventura
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
- Institute of Biology II, Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104, Freiburg, Germany
| | - Mehmet Ali Öztürk
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Schänzlestr. 18, 79104, Freiburg, Germany
- Institute of Biology II, Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104, Freiburg, Germany
| |
Collapse
|
5
|
Butler ND, Kunjapur AM. Selective and Site-Specific Incorporation of Nonstandard Amino Acids Within Proteins for Therapeutic Applications. Methods Mol Biol 2024; 2720:35-53. [PMID: 37775656 DOI: 10.1007/978-1-0716-3469-1_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/01/2023]
Abstract
The incorporation of nonstandard amino acids (nsAAs) within protein sequences has broadened the chemical functionalities available for use in the study, prevention, or treatment of disease. The ability to genetically encode the introduction of nsAAs at precise sites of target recombinant proteins has enabled numerous applications such as bioorthogonal conjugation, thrombin inhibition, intrinsic biological containment of live organisms, and immunochemical termination of self-tolerance. Genetic systems that perform critical steps in enabling nsAA incorporation are known as orthogonal translation systems or orthogonal aminoacyl-tRNA synthetase/tRNA pairs. In Escherichia coli, several of these have been designed to accept novel nsAAs. Certain endogenous proteins, codon context, and standard amino acid concentrations can affect the yield of recombinant protein, the rate of nsAA incorporation within off-target proteins, and the rate of misincorporation due to near-cognate suppression or misacylation of orthogonal tRNA with standard amino acids. As a result, a significant body of work has been performed in engineering the E. coli genome to alleviate these issues. Here, we describe common methods applicable to nsAA incorporation within proteins in E. coli for sufficient purity and characterization for downstream therapeutic applications.
Collapse
Affiliation(s)
- Neil D Butler
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, USA
| | - Aditya M Kunjapur
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, USA.
| |
Collapse
|
6
|
Fuertes G, Sakamoto K, Budisa N. Editorial: Exploring and expanding the protein universe with non-canonical amino acids. Front Mol Biosci 2023; 10:1303286. [PMID: 37900919 PMCID: PMC10602797 DOI: 10.3389/fmolb.2023.1303286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 10/02/2023] [Indexed: 10/31/2023] Open
Affiliation(s)
- Gustavo Fuertes
- Laboratory of Biomolecular Recognition, Institute of Biotechnology of the Czech Academy of Sciences, Vestec, Czechia
| | - Kensaku Sakamoto
- Laboratory for Nonnatural Amino Acid Technology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Japan
| | - Nediljko Budisa
- Chemical Synthetic Biology Group, Department of Chemistry, University of Manitoba, Winnipeg, Canada
| |
Collapse
|
7
|
Jenne F, Berezkin I, Tempel F, Schmidt D, Popov R, Nesterov-Mueller A. Screening for Primordial RNA–Peptide Interactions Using High-Density Peptide Arrays. Life (Basel) 2023; 13:life13030796. [PMID: 36983951 PMCID: PMC10053474 DOI: 10.3390/life13030796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 03/08/2023] [Accepted: 03/13/2023] [Indexed: 03/17/2023] Open
Abstract
RNA–peptide interactions are an important factor in the origin of the modern mechanism of translation and the genetic code. Despite great progress in the bioinformatics of RNA–peptide interactions due to the rapid growth in the number of known RNA–protein complexes, there is no comprehensive experimental method to take into account the influence of individual amino acids on non-covalent RNA–peptide bonds. First, we designed the combinatorial libraries of primordial peptides according to the combinatorial fusion rules based on Watson–Crick mutations. Next, we used high-density peptide arrays to investigate the interaction of primordial peptides with their cognate homo-oligonucleotides. We calculated the interaction scores of individual peptide fragments and evaluated the influence of the peptide length and its composition on the strength of RNA binding. The analysis shows that the amino acids phenylalanine, tyrosine, and proline contribute significantly to the strong binding between peptides and homo-oligonucleotides, while the sum charge of the peptide does not have a significant effect. We discuss the physicochemical implications of the combinatorial fusion cascade, a hypothesis that follows from the amino acid partition used in the work.
Collapse
Affiliation(s)
- Felix Jenne
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, DE-76344 Eggenstein-Leopoldshafen, Germany
| | - Ivan Berezkin
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, DE-76344 Eggenstein-Leopoldshafen, Germany
| | - Frank Tempel
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, DE-76344 Eggenstein-Leopoldshafen, Germany
| | - Dimitry Schmidt
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, DE-76344 Eggenstein-Leopoldshafen, Germany
| | | | - Alexander Nesterov-Mueller
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, DE-76344 Eggenstein-Leopoldshafen, Germany
- Correspondence: ; Tel.: +49-721-608-29253
| |
Collapse
|
8
|
Sisila V, Indhu M, Radhakrishnan J, Ayyadurai N. Building biomaterials through genetic code expansion. Trends Biotechnol 2023; 41:165-183. [PMID: 35908989 DOI: 10.1016/j.tibtech.2022.07.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 06/30/2022] [Accepted: 07/08/2022] [Indexed: 01/24/2023]
Abstract
Genetic code expansion (GCE) enables directed incorporation of noncoded amino acids (NCAAs) and unnatural amino acids (UNAAs) into the active core that confers dedicated structure and function to engineered proteins. Many protein biomaterials are tandem repeats that intrinsically include NCAAs generated through post-translational modifications (PTMs) to execute assigned functions. Conventional genetic engineering approaches using prokaryotic systems have limited ability to biosynthesize functionally active biomaterials with NCAAs/UNAAs. Codon suppression and reassignment introduce NCAAs/UNAAs globally, allowing engineered proteins to be redesigned to mimic natural matrix-cell interactions for tissue engineering. Expanding the genetic code enables the engineering of biomaterials with catechols - growth factor mimetics that modulate cell-matrix interactions - thereby facilitating tissue-specific expression of genes and proteins. This method of protein engineering shows promise in achieving tissue-informed, tissue-compliant tunable biomaterials.
Collapse
Affiliation(s)
- Valappil Sisila
- Department of Biochemistry and Biotechnology, Council of Scientific and Industrial Research (CSIR) Central Leather Research Institute (CLRI), Chennai, Tamil Nadu 600020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, India
| | - Mohan Indhu
- Department of Biochemistry and Biotechnology, Council of Scientific and Industrial Research (CSIR) Central Leather Research Institute (CLRI), Chennai, Tamil Nadu 600020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, India
| | - Janani Radhakrishnan
- Department of Biochemistry and Biotechnology, Council of Scientific and Industrial Research (CSIR) Central Leather Research Institute (CLRI), Chennai, Tamil Nadu 600020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, India.
| | - Niraikulam Ayyadurai
- Department of Biochemistry and Biotechnology, Council of Scientific and Industrial Research (CSIR) Central Leather Research Institute (CLRI), Chennai, Tamil Nadu 600020, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, India.
| |
Collapse
|
9
|
Meganathan I, Pachaiyappan M, Aarthy M, Radhakrishnan J, Mukherjee S, Shanmugam G, You J, Ayyadurai N. Recombinant and genetic code expanded collagen-like protein as a tailorable biomaterial. MATERIALS HORIZONS 2022; 9:2698-2721. [PMID: 36189465 DOI: 10.1039/d2mh00652a] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Collagen occurs in nature with a dedicated triple helix structure and is the most preferred biomaterial in commercialized medical products. However, concerns on purity, disease transmission, and the reproducibility of animal derived collagen restrict its applications and warrants alternate recombinant sources. The expression of recombinant collagen in different prokaryotic and eukaryotic hosts has been reported with varying degrees of success, however, it is vital to elucidate the structural and biological characteristics of natural collagen. The recombinant production of biologically functional collagen is restricted by its high molecular weight and post-translational modification (PTM), especially the hydroxylation of proline to hydroxyproline. Hydroxyproline plays a key role in the structural stability and higher order self-assembly to form fibrillar matrices. Advancements in synthetic biology and recombinant technology are being explored for improving the yield and biomimicry of recombinant collagen. It emerges as reliable, sustainable source of collagen, promises tailorable properties and thereby custom-made protein biomaterials. Remarkably, the evolutionary existence of collagen-like proteins (CLPs) has been identified in single-cell organisms. Interestingly, CLPs exhibit remarkable ability to form stable triple helical structures similar to animal collagen and have gained increasing attention. Strategies to expand the genetic code of CLPs through the incorporation of unnatural amino acids promise the synthesis of highly tunable next-generation triple helical proteins required for the fabrication of smart biomaterials. The review outlines the importance of collagen, sources and diversification, and animal and recombinant collagen-based biomaterials and highlights the limitations of the existing collagen sources. The emphasis on genetic code expanded tailorable CLPs as the most sought alternate for the production of functional collagen and its advantages as translatable biomaterials has been highlighted.
Collapse
Affiliation(s)
- Ilamaran Meganathan
- Division of Biochemistry and Biotechnology, Council of Scientific and Industrial Research (CSIR) - CLRI, Chennai, India.
| | - Mohandass Pachaiyappan
- Division of Biochemistry and Biotechnology, Council of Scientific and Industrial Research (CSIR) - CLRI, Chennai, India.
| | - Mayilvahanan Aarthy
- Division of Biochemistry and Biotechnology, Council of Scientific and Industrial Research (CSIR) - CLRI, Chennai, India.
| | - Janani Radhakrishnan
- Division of Biochemistry and Biotechnology, Council of Scientific and Industrial Research (CSIR) - CLRI, Chennai, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Smriti Mukherjee
- Division of Organic and Bio-organic Chemistry, Council of Scientific and Industrial Research (CSIR) - CLRI, Chennai, India
| | - Ganesh Shanmugam
- Division of Organic and Bio-organic Chemistry, Council of Scientific and Industrial Research (CSIR) - CLRI, Chennai, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Jingjing You
- Save Sight Institute, Sydney Medical School, University of Sydney, Australia
| | - Niraikulam Ayyadurai
- Division of Biochemistry and Biotechnology, Council of Scientific and Industrial Research (CSIR) - CLRI, Chennai, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| |
Collapse
|
10
|
Tittle JM, Schwark DG, Biddle W, Schmitt MA, Fisk JD. Impact of queuosine modification of endogenous E. coli tRNAs on sense codon reassignment. Front Mol Biosci 2022; 9:938114. [PMID: 36120552 PMCID: PMC9471426 DOI: 10.3389/fmolb.2022.938114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 07/27/2022] [Indexed: 11/13/2022] Open
Abstract
The extent to which alteration of endogenous tRNA modifications may be exploited to improve genetic code expansion efforts has not been broadly investigated. Modifications of tRNAs are strongly conserved evolutionarily, but the vast majority of E. coli tRNA modifications are not essential. We identified queuosine (Q), a non-essential, hypermodified guanosine nucleoside found in position 34 of the anticodons of four E. coli tRNAs as a modification that could potentially be utilized to improve sense codon reassignment. One suggested purpose of queuosine modification is to reduce the preference of tRNAs with guanosine (G) at position 34 of the anticodon for decoding cytosine (C) ending codons over uridine (U) ending codons. We hypothesized that introduced orthogonal translation machinery with adenine (A) at position 34 would reassign U-ending codons more effectively in queuosine-deficient E. coli. We evaluated the ability of introduced orthogonal tRNAs with AUN anticodons to reassign three of the four U-ending codons normally decoded by Q34 endogenous tRNAs: histidine CAU, asparagine AAU, and aspartic acid GAU in the presence and absence of queuosine modification. We found that sense codon reassignment efficiencies in queuosine-deficient strains are slightly improved at Asn AAU, equivalent at His CAU, and less efficient at Asp GAU codons. Utilization of orthogonal pair-directed sense codon reassignment to evaluate competition events that do not occur in the standard genetic code suggests that tRNAs with inosine (I, 6-deaminated A) at position 34 compete much more favorably against G34 tRNAs than Q34 tRNAs. Continued evaluation of sense codon reassignment following targeted alterations to endogenous tRNA modifications has the potential to shed new light on the web of interactions that combine to preserve the fidelity of the genetic code as well as identify opportunities for exploitation in systems with expanded genetic codes.
Collapse
|
11
|
Kimoto M, Hirao I. Genetic Code Engineering by Natural and Unnatural Base Pair Systems for the Site-Specific Incorporation of Non-Standard Amino Acids Into Proteins. Front Mol Biosci 2022; 9:851646. [PMID: 35685243 PMCID: PMC9171071 DOI: 10.3389/fmolb.2022.851646] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 04/25/2022] [Indexed: 12/21/2022] Open
Abstract
Amino acid sequences of proteins are encoded in nucleic acids composed of four letters, A, G, C, and T(U). However, this four-letter alphabet coding system limits further functionalities of proteins by the twenty letters of amino acids. If we expand the genetic code or develop alternative codes, we could create novel biological systems and biotechnologies by the site-specific incorporation of non-standard amino acids (or unnatural amino acids, unAAs) into proteins. To this end, new codons and their complementary anticodons are required for unAAs. In this review, we introduce the current status of methods to incorporate new amino acids into proteins by in vitro and in vivo translation systems, by focusing on the creation of new codon-anticodon interactions, including unnatural base pair systems for genetic alphabet expansion.
Collapse
Affiliation(s)
| | - Ichiro Hirao
- *Correspondence: Michiko Kimoto, ; Ichiro Hirao,
| |
Collapse
|
12
|
Li J, Tang M, Qi H. Codon-Reduced Protein Synthesis With Manipulating tRNA Components in Cell-Free System. Front Bioeng Biotechnol 2022; 10:891808. [PMID: 35646841 PMCID: PMC9136035 DOI: 10.3389/fbioe.2022.891808] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 04/25/2022] [Indexed: 11/13/2022] Open
Abstract
Manipulating transfer RNAs (tRNAs) for emancipating sense codons to simplify genetic codons in a cell-free protein synthesis (CFPS) system can offer more flexibility and controllability. Here, we provide an overview of the tRNA complement protein synthesis system construction in the tRNA-depleted Protein synthesis Using purified Recombinant Elements (PURE) system or S30 extract. These designed polypeptide coding sequences reduce the genetic codon and contain only a single tRNA corresponding to a single amino acid in this presented system. Strategies for removing tRNAs from cell lysates and synthesizing tRNAs in vivo/vitro are summarized and discussed in detail. Furthermore, we point out the trend toward a minimized genetic codon for reducing codon redundancy by manipulating tRNAs in the different proteins. It is hoped that the tRNA complement protein synthesis system can facilitate the construction of minimal cells and expand the biomedical application scope of synthetic biology.
Collapse
Affiliation(s)
- Jiaojiao Li
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, China
| | - Mengtong Tang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, China
| | - Hao Qi
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
- Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, China
- *Correspondence: Hao Qi,
| |
Collapse
|
13
|
Biddle W, Schwark DG, Schmitt MA, Fisk JD. Directed Evolution Pipeline for the Improvement of Orthogonal Translation Machinery for Genetic Code Expansion at Sense Codons. Front Chem 2022; 10:815788. [PMID: 35252113 PMCID: PMC8891652 DOI: 10.3389/fchem.2022.815788] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 01/24/2022] [Indexed: 12/30/2022] Open
Abstract
The expansion of the genetic code beyond a single type of noncanonical amino acid (ncAA) is hindered by inefficient machinery for reassigning the meaning of sense codons. A major obstacle to using directed evolution to improve the efficiency of sense codon reassignment is that fractional sense codon reassignments lead to heterogeneous mixtures of full-length proteins with either a ncAA or a natural amino acid incorporated in response to the targeted codon. In stop codon suppression systems, missed incorporations lead to truncated proteins; improvements in activity may be inferred from increased protein yields or the production of downstream reporters. In sense codon reassignment, the heterogeneous proteins produced greatly complicate the development of screens for variants of the orthogonal machinery with improved activity. We describe the use of a previously-reported fluorescence-based screen for sense codon reassignment as the first step in a directed evolution workflow to improve the incorporation of a ncAA in response to the Arg AGG sense codon. We first screened a library with diversity introduced into both the orthogonal Methanocaldococcus jannaschii tyrosyl tRNA anticodon loop and the cognate aminoacyl tRNA synthetase (aaRS) anticodon binding domain for variants that improved incorporation of tyrosine in response to the AGG codon. The most efficient variants produced fluorescent proteins at levels indistinguishable from the E. coli translation machinery decoding tyrosine codons. Mutations to the M. jannaschii aaRS that were found to improve tyrosine incorporation were transplanted onto a M. jannaschii aaRS evolved for the incorporation of para-azidophenylalanine. Improved ncAA incorporation was evident using fluorescence- and mass-based reporters. The described workflow is generalizable and should enable the rapid tailoring of orthogonal machinery capable of activating diverse ncAAs to any sense codon target. We evaluated the selection based improvements of the orthogonal pair in a host genomically engineered for reduced target codon competition. Using this particular system for evaluation of arginine AGG codon reassignment, however, E. coli strains with genomes engineered to remove competing tRNAs did not outperform a standard laboratory E. coli strain in sense codon reassignment.
Collapse
|
14
|
Lateef OM, Akintubosun MO, Olaoba OT, Samson SO, Adamczyk M. Making Sense of "Nonsense" and More: Challenges and Opportunities in the Genetic Code Expansion, in the World of tRNA Modifications. Int J Mol Sci 2022; 23:938. [PMID: 35055121 PMCID: PMC8779196 DOI: 10.3390/ijms23020938] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/10/2022] [Accepted: 01/12/2022] [Indexed: 01/09/2023] Open
Abstract
The evolutional development of the RNA translation process that leads to protein synthesis based on naturally occurring amino acids has its continuation via synthetic biology, the so-called rational bioengineering. Genetic code expansion (GCE) explores beyond the natural translational processes to further enhance the structural properties and augment the functionality of a wide range of proteins. Prokaryotic and eukaryotic ribosomal machinery have been proven to accept engineered tRNAs from orthogonal organisms to efficiently incorporate noncanonical amino acids (ncAAs) with rationally designed side chains. These side chains can be reactive or functional groups, which can be extensively utilized in biochemical, biophysical, and cellular studies. Genetic code extension offers the contingency of introducing more than one ncAA into protein through frameshift suppression, multi-site-specific incorporation of ncAAs, thereby increasing the vast number of possible applications. However, different mediating factors reduce the yield and efficiency of ncAA incorporation into synthetic proteins. In this review, we comment on the recent advancements in genetic code expansion to signify the relevance of systems biology in improving ncAA incorporation efficiency. We discuss the emerging impact of tRNA modifications and metabolism in protein design. We also provide examples of the latest successful accomplishments in synthetic protein therapeutics and show how codon expansion has been employed in various scientific and biotechnological applications.
Collapse
Affiliation(s)
- Olubodun Michael Lateef
- Faculty of Chemistry, Warsaw University of Technology, 00-664 Warsaw, Poland; (O.M.L.); (M.O.A.); (S.O.S.)
| | | | - Olamide Tosin Olaoba
- Laboratory of Functional and Structural Biochemistry, Federal University of Sao Carlos, Sao Carlos 13565-905, SP, Brazil;
| | - Sunday Ocholi Samson
- Faculty of Chemistry, Warsaw University of Technology, 00-664 Warsaw, Poland; (O.M.L.); (M.O.A.); (S.O.S.)
| | - Malgorzata Adamczyk
- Faculty of Chemistry, Warsaw University of Technology, 00-664 Warsaw, Poland; (O.M.L.); (M.O.A.); (S.O.S.)
| |
Collapse
|
15
|
Mollé LM, Smyth CH, Yuen D, Johnston APR. Nanoparticles for vaccine and gene therapy: Overcoming the barriers to nucleic acid delivery. WILEY INTERDISCIPLINARY REVIEWS. NANOMEDICINE AND NANOBIOTECHNOLOGY 2022; 14:e1809. [PMID: 36416028 PMCID: PMC9786906 DOI: 10.1002/wnan.1809] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 04/19/2022] [Accepted: 04/24/2022] [Indexed: 11/24/2022]
Abstract
Nucleic acid therapeutics can be used to control virtually every aspect of cell behavior and therefore have significant potential to treat genetic disorders, infectious diseases, and cancer. However, while clinically approved to treat a small number of diseases, the full potential of nucleic acid therapeutics is hampered by inefficient delivery. Nucleic acids are large, highly charged biomolecules that are sensitive to degradation and so the approaches to deliver these molecules differ significantly from traditional small molecule drugs. Current studies suggest less than 1% of the injected nucleic acid dose is delivered to the target cell in an active form. This inefficient delivery increases costs and limits their use to applications where a small amount of nucleic acid is sufficient. In this review, we focus on two of the major barriers to efficient nucleic acid delivery: (1) delivery to the target cell and (2) transport to the subcellular compartment where the nucleic acids are therapeutically active. We explore how nanoparticles can be modified with targeting ligands to increase accumulation in specific cells, and how the composition of the nanoparticle can be engineered to manipulate or disrupt cellular membranes and facilitate delivery to the optimal subcellular compartments. Finally, we highlight how with intelligent material design, nanoparticle delivery systems have been developed to deliver nucleic acids that silence aberrant genes, correct genetic mutations, and act as both therapeutic and prophylactic vaccines. This article is categorized under: Nanotechnology Approaches to Biology > Cells at the Nanoscale Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Biology-Inspired Nanomaterials > Lipid-Based Structures.
Collapse
Affiliation(s)
- Lara M. Mollé
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical SciencesMonash UniversityParkvilleVictoriaAustralia
| | - Cameron H. Smyth
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical SciencesMonash UniversityParkvilleVictoriaAustralia
| | - Daniel Yuen
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical SciencesMonash UniversityParkvilleVictoriaAustralia
| | - Angus P. R. Johnston
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical SciencesMonash UniversityParkvilleVictoriaAustralia
| |
Collapse
|
16
|
Wang YH, Jian ML, Chen PJ, Tsou JC, Truong LP, Wang YS. Ferritin Conjugates With Multiple Clickable Amino Acids Encoded by C-Terminal Engineered Pyrrolysyl-tRNA Synthetase. Front Chem 2021; 9:779976. [PMID: 34900939 PMCID: PMC8655692 DOI: 10.3389/fchem.2021.779976] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 10/20/2021] [Indexed: 11/30/2022] Open
Abstract
This study reports the application of expanding genetic codes in developing protein cage-based delivery systems. The evolved Methanosarcina mazei pyrrolysyl-tRNA synthetase (PylRS)•tRNAPyl pairs derived from directed evolution are examined to probe their recognition for para-substituted phenylalanine analogs. The evolved MmPylRS, AzFRS, harboring a wide range of substrates, is further engineered at the C-terminal region into another variant, AzFRS-MS. AzFRS-MS shows suppression of the elevated sfGFP protein amount up to 10 TAG stop codons when charging p-azido-l-phenylalanine (AzF, 4), which allows the occurrence of click chemistry. Since protein nanocages used as drug delivery systems that encompass multiple drugs through a site-specific loading approach remain largely unexplored, as a proof of concept, the application of AzFRS-MS for the site-specific incorporation of AzF on human heavy chain ferritin (Ftn) is developed. The Ftn-4 conjugate is shown to be able to load multiple fluorescence dyes or a therapeutic agent, doxorubicin (Dox), through the strain-promoted azide-alkyne cycloaddition (SPAAC) click reaction. Aiming to selectively target Her2+ breast cancer cells, Ftn-4-DOX conjugates fused with a HER2 receptor recognition peptide, anti-Her2/neu peptide (AHNP), is developed and demonstrated to be able to deliver Dox into the cell and to prolong the drug release. This work presents another application of evolved MmPylRS systems, whose potential in developing a variety of protein conjugates is noteworthy.
Collapse
Affiliation(s)
- Yi-Hui Wang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Mu-Lung Jian
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.,Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Pei-Jung Chen
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.,Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Jo-Chu Tsou
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.,Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Le P Truong
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Yane-Shih Wang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.,Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan
| |
Collapse
|
17
|
Lee BS, Choi WJ, Lee SW, Ko BJ, Yoo TH. Towards Engineering an Orthogonal Protein Translation Initiation System. Front Chem 2021; 9:772648. [PMID: 34765589 PMCID: PMC8576571 DOI: 10.3389/fchem.2021.772648] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 10/14/2021] [Indexed: 11/24/2022] Open
Abstract
In the last two decades, methods to incorporate non-canonical amino acids (ncAAs) into specific positions of a protein have advanced significantly; these methods have become general tools for engineering proteins. However, almost all these methods depend on the translation elongation process, and strategies leveraging the initiation process have rarely been reported. The incorporation of a ncAA specifically at the translation initiation site enables the installation of reactive groups for modification at the N-termini of proteins, which are attractive positions for introducing abiological groups with minimal structural perturbations. In this study, we attempted to engineer an orthogonal protein translation initiation system. Introduction of the identity elements of Escherichia coli initiator tRNA converted an engineered Methanococcus jannaschii tRNATyr into an initiator tRNA. The engineered tRNA enabled the site-specific incorporation of O-propargyl-l-tyrosine (OpgY) into the amber (TAG) codon at the translation initiation position but was inactive toward the elongational TAG codon. Misincorporation of Gln was detected, and the engineered system was demonstrated only with OpgY. We expect further engineering of the initiator tRNA for improved activity and specificity to generate an orthogonal translation initiation system.
Collapse
Affiliation(s)
- Byeong Sung Lee
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea
| | - Woon Jong Choi
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea
| | - Sang Woo Lee
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea
| | - Byoung Joon Ko
- School of Biopharmaceutical and Medical Sciences, Sungshin Women's University, Seoul, South Korea
| | - Tae Hyeon Yoo
- Department of Molecular Science and Technology, Ajou University, Suwon, South Korea.,Department of Applied Chemistry and Biological Engineering, Ajou University, Suwon, South Korea
| |
Collapse
|
18
|
Shulgina Y, Eddy SR. A computational screen for alternative genetic codes in over 250,000 genomes. eLife 2021; 10:71402. [PMID: 34751130 PMCID: PMC8629427 DOI: 10.7554/elife.71402] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 10/26/2021] [Indexed: 11/25/2022] Open
Abstract
The genetic code has been proposed to be a ‘frozen accident,’ but the discovery of alternative genetic codes over the past four decades has shown that it can evolve to some degree. Since most examples were found anecdotally, it is difficult to draw general conclusions about the evolutionary trajectories of codon reassignment and why some codons are affected more frequently. To fill in the diversity of genetic codes, we developed Codetta, a computational method to predict the amino acid decoding of each codon from nucleotide sequence data. We surveyed the genetic code usage of over 250,000 bacterial and archaeal genome sequences in GenBank and discovered five new reassignments of arginine codons (AGG, CGA, and CGG), representing the first sense codon changes in bacteria. In a clade of uncultivated Bacilli, the reassignment of AGG to become the dominant methionine codon likely evolved by a change in the amino acid charging of an arginine tRNA. The reassignments of CGA and/or CGG were found in genomes with low GC content, an evolutionary force that likely helped drive these codons to low frequency and enable their reassignment. All life forms rely on a ‘code’ to translate their genetic information into proteins. This code relies on limited permutations of three nucleotides – the building blocks that form DNA and other types of genetic information. Each ‘triplet’ of nucleotides – or codon – encodes a specific amino acid, the basic component of proteins. Reading the sequence of codons in the right order will let the cell know which amino acid to assemble next on a growing protein. For instance, the codon CGG – formed of the nucleotides guanine (G) and cytosine (C) – codes for the amino acid arginine. From bacteria to humans, most life forms rely on the same genetic code. Yet certain organisms have evolved to use slightly different codes, where one or several codons have an altered meaning. To better understand how alternative genetic codes have evolved, Shulgina and Eddy set out to find more organisms featuring these altered codons, creating a new software called Codetta that can analyze the genome of a microorganism and predict the genetic code it uses. Codetta was then used to sift through the genetic information of 250,000 microorganisms. This was made possible by the sequencing, in recent years, of the genomes of hundreds of thousands of bacteria and other microorganisms – including many never studied before. These analyses revealed five groups of bacteria with alternative genetic codes, all of which had changes in the codons that code for arginine. Amongst these, four had genomes with a low proportion of guanine and cytosine nucleotides. This may have made some guanine and cytosine-rich arginine codons very rare in these organisms and, therefore, easier to be reassigned to encode another amino acid. The work by Shulgina and Eddy demonstrates that Codetta is a new, useful tool that scientists can use to understand how genetic codes evolve. In addition, it can also help to ensure the accuracy of widely used protein databases, which assume which genetic code organisms use to predict protein sequences from their genomes.
Collapse
Affiliation(s)
| | - Sean R Eddy
- Molecular & Cellular Biology, Harvard University, Cambridge, United States
| |
Collapse
|
19
|
Lammers M. Post-translational Lysine Ac(et)ylation in Bacteria: A Biochemical, Structural, and Synthetic Biological Perspective. Front Microbiol 2021; 12:757179. [PMID: 34721364 PMCID: PMC8556138 DOI: 10.3389/fmicb.2021.757179] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 09/10/2021] [Indexed: 12/21/2022] Open
Abstract
Ac(et)ylation is a post-translational modification present in all domains of life. First identified in mammals in histones to regulate RNA synthesis, today it is known that is regulates fundamental cellular processes also in bacteria: transcription, translation, metabolism, cell motility. Ac(et)ylation can occur at the ε-amino group of lysine side chains or at the α-amino group of a protein. Furthermore small molecules such as polyamines and antibiotics can be acetylated and deacetylated enzymatically at amino groups. While much research focused on N-(ε)-ac(et)ylation of lysine side chains, much less is known about the occurrence, the regulation and the physiological roles on N-(α)-ac(et)ylation of protein amino termini in bacteria. Lysine ac(et)ylation was shown to affect protein function by various mechanisms ranging from quenching of the positive charge, increasing the lysine side chains’ size affecting the protein surface complementarity, increasing the hydrophobicity and by interfering with other post-translational modifications. While N-(ε)-lysine ac(et)ylation was shown to be reversible, dynamically regulated by lysine acetyltransferases and lysine deacetylases, for N-(α)-ac(et)ylation only N-terminal acetyltransferases were identified and so far no deacetylases were discovered neither in bacteria nor in mammals. To this end, N-terminal ac(et)ylation is regarded as being irreversible. Besides enzymatic ac(et)ylation, recent data showed that ac(et)ylation of lysine side chains and of the proteins N-termini can also occur non-enzymatically by the high-energy molecules acetyl-coenzyme A and acetyl-phosphate. Acetyl-phosphate is supposed to be the key molecule that drives non-enzymatic ac(et)ylation in bacteria. Non-enzymatic ac(et)ylation can occur site-specifically with both, the protein primary sequence and the three dimensional structure affecting its efficiency. Ac(et)ylation is tightly controlled by the cellular metabolic state as acetyltransferases use ac(et)yl-CoA as donor molecule for the ac(et)ylation and sirtuin deacetylases use NAD+ as co-substrate for the deac(et)ylation. Moreover, the accumulation of ac(et)yl-CoA and acetyl-phosphate is dependent on the cellular metabolic state. This constitutes a feedback control mechanism as activities of many metabolic enzymes were shown to be regulated by lysine ac(et)ylation. Our knowledge on lysine ac(et)ylation significantly increased in the last decade predominantly due to the huge methodological advances that were made in fields such as mass-spectrometry, structural biology and synthetic biology. This also includes the identification of additional acylations occurring on lysine side chains with supposedly different regulatory potential. This review highlights recent advances in the research field. Our knowledge on enzymatic regulation of lysine ac(et)ylation will be summarized with a special focus on structural and mechanistic characterization of the enzymes, the mechanisms underlying non-enzymatic/chemical ac(et)ylation are explained, recent technological progress in the field are presented and selected examples highlighting the important physiological roles of lysine ac(et)ylation are summarized.
Collapse
Affiliation(s)
- Michael Lammers
- Synthetic and Structural Biochemistry, Institute for Biochemistry, University of Greifswald, Greifswald, Germany
| |
Collapse
|
20
|
Romesberg FE. Creation, Optimization, and Use of Semi-Synthetic Organisms that Store and Retrieve Increased Genetic Information. J Mol Biol 2021; 434:167331. [PMID: 34710400 DOI: 10.1016/j.jmb.2021.167331] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 10/18/2021] [Accepted: 10/20/2021] [Indexed: 12/18/2022]
Abstract
With few exceptions, natural proteins are built from only 20 canonical (proteogenic) amino acids which limits the functionality and accordingly the properties they can possess. Genetic code expansion, i.e. the creation of codons and the machinery needed to assign them to non-canonical amino acids (ncAAs), promises to enable the discovery of proteins with novel properties that are otherwise difficult or impossible to obtain. One approach to expanding the genetic code is to expand the genetic alphabet via the development of unnatural nucleotides that pair to form an unnatural base pair (UBP). Semi-synthetic organisms (SSOs), i.e. organisms that stably maintain the UBP, transcribe its component nucleotides into RNA, and use it to translate proteins, would have available to them new codons and the anticodons needed to assign them to ncAAs. This review summarizes the development of a family of UBPs, their use to create SSOs, and the optimization and application of the SSOs to produce candidate therapeutic proteins with improved properties that are now undergoing evaluation in clinical trials.
Collapse
|
21
|
Arnolds KL, Dahlin LR, Ding L, Wu C, Yu J, Xiong W, Zuniga C, Suzuki Y, Zengler K, Linger JG, Guarnieri MT. Biotechnology for secure biocontainment designs in an emerging bioeconomy. Curr Opin Biotechnol 2021; 71:25-31. [PMID: 34091124 DOI: 10.1016/j.copbio.2021.05.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/21/2021] [Accepted: 05/10/2021] [Indexed: 12/28/2022]
Abstract
Genetically modified organisms (GMOs) have emerged as an integral component of a sustainable bioeconomy, with an array of applications in agriculture, bioenergy, and biomedicine. However, the rapid development of GMOs and associated synthetic biology approaches raises a number of biosecurity concerns related to environmental escape of GMOs, detection thereof, and impact upon native ecosystems. A myriad of genetic safeguards have been deployed in diverse microbial hosts, ranging from classical auxotrophies to global genome recoding. However, to realize the full potential of microbes as biocatalytic platforms in the bioeconomy, a deeper understanding of the fundamental principles governing microbial responsiveness to biocontainment constraints, and interactivity of GMOs with the environment, is required. Herein, we review recent analytical biotechnological advances and strategies to assess biocontainment and microbial bioproductivity, as well as opportunities for predictive systems biodesigns towards securing a viable bioeconomy.
Collapse
Affiliation(s)
| | - Lukas R Dahlin
- National Renewable Energy Laboratory, Golden, CO, United States
| | - Lin Ding
- J. Craig Venter Institute, La Jolla, CA, United States
| | - Chao Wu
- National Renewable Energy Laboratory, Golden, CO, United States
| | - Jianping Yu
- National Renewable Energy Laboratory, Golden, CO, United States
| | - Wei Xiong
- National Renewable Energy Laboratory, Golden, CO, United States
| | - Cristal Zuniga
- University of California, San Diego, La Jolla, CA, United States
| | - Yo Suzuki
- J. Craig Venter Institute, La Jolla, CA, United States
| | - Karsten Zengler
- University of California, San Diego, La Jolla, CA, United States
| | | | | |
Collapse
|
22
|
Tharp JM, Vargas-Rodriguez O, Schepartz A, Söll D. Genetic Encoding of Three Distinct Noncanonical Amino Acids Using Reprogrammed Initiator and Nonsense Codons. ACS Chem Biol 2021; 16:766-774. [PMID: 33723984 DOI: 10.1021/acschembio.1c00120] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We recently described an orthogonal initiator tRNA (itRNATy2) that can initiate protein synthesis with noncanonical amino acids (ncAAs) in response to the UAG nonsense codon. Here, we report that a mutant of itRNATy2 (itRNATy2AUA) can efficiently initiate translation in response to the UAU tyrosine codon, giving rise to proteins with an ncAA at their N-terminus. We show that, in cells expressing itRNATy2AUA, UAU can function as a dual-use codon that selectively encodes ncAAs at the initiating position and predominantly tyrosine at elongating positions. Using itRNATy2AUA, in conjunction with its cognate tyrosyl-tRNA synthetase and two mutually orthogonal pyrrolysyl-tRNA synthetases, we demonstrate that UAU can be reassigned along with UAG or UAA to encode two distinct ncAAs in the same protein. Furthermore, by engineering the substrate specificity of one of the pyrrolysyl-tRNA synthetases, we developed a triply orthogonal system that enables simultaneous reassignment of UAU, UAG, and UAA to produce proteins containing three distinct ncAAs at precisely defined sites. To showcase the utility of this system, we produced proteins containing two or three ncAAs, with unique bioorthogonal functional groups, and demonstrate that these proteins can be separately modified with multiple fluorescent probes.
Collapse
|
23
|
Schmidt M, Kubyshkin V. How To Quantify a Genetic Firewall? A Polarity-Based Metric for Genetic Code Engineering. Chembiochem 2021; 22:1268-1284. [PMID: 33231343 PMCID: PMC8049029 DOI: 10.1002/cbic.202000758] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 11/20/2020] [Indexed: 12/14/2022]
Abstract
Genetic code engineering aims to produce organisms that translate genetic information in a different way from that prescribed by the standard genetic code. This endeavor could eventually lead to genetic isolation, where an organism that operates under a different genetic code will not be able to transfer functional genes with other living species, thereby standing behind a genetic firewall. It is not clear however, how distinct the code should be, or how to measure the distance. We have developed a metric (Δcode ) where we assigned polarity indices (clog D7 ) to amino acids to calculate the distances between pairs of genetic codes. We then calculated the distance between a set of 204 genetic codes, including the 24 known distinct natural codes, 11 extreme-distance codes created computationally, nine theoretical special purpose codes from literature and 160 codes in which canonical amino acids were replaced by noncanonical chemical analogues. The metric can be used for building strategies towards creating semantically alienated organisms, and testing the strength of genetic firewalls. This metric provides the basis for a map of the genetic codes that could guide future efforts towards novel biochemical worlds, biosafety and deep barcoding applications.
Collapse
Affiliation(s)
| | - Vladimir Kubyshkin
- Department of ChemistryUniversity of ManitobaDysart Road 144WinnipegR3T 2N2Canada
| |
Collapse
|
24
|
Manandhar M, Chun E, Romesberg FE. Genetic Code Expansion: Inception, Development, Commercialization. J Am Chem Soc 2021; 143:4859-4878. [DOI: 10.1021/jacs.0c11938] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Miglena Manandhar
- Synthorx, a Sanofi Company, La Jolla, California 92037, United States
| | - Eugene Chun
- Synthorx, a Sanofi Company, La Jolla, California 92037, United States
| | | |
Collapse
|
25
|
Schwark DG, Schmitt MA, Fisk JD. Directed Evolution of the Methanosarcina barkeri Pyrrolysyl tRNA/aminoacyl tRNA Synthetase Pair for Rapid Evaluation of Sense Codon Reassignment Potential. Int J Mol Sci 2021; 22:E895. [PMID: 33477414 PMCID: PMC7830368 DOI: 10.3390/ijms22020895] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/10/2021] [Accepted: 01/12/2021] [Indexed: 12/20/2022] Open
Abstract
Genetic code expansion has largely focused on the reassignment of amber stop codons to insert single copies of non-canonical amino acids (ncAAs) into proteins. Increasing effort has been directed at employing the set of aminoacyl tRNA synthetase (aaRS) variants previously evolved for amber suppression to incorporate multiple copies of ncAAs in response to sense codons in Escherichia coli. Predicting which sense codons are most amenable to reassignment and which orthogonal translation machinery is best suited to each codon is challenging. This manuscript describes the directed evolution of a new, highly efficient variant of the Methanosarcina barkeri pyrrolysyl orthogonal tRNA/aaRS pair that activates and incorporates tyrosine. The evolved M. barkeri tRNA/aaRS pair reprograms the amber stop codon with 98.1 ± 3.6% efficiency in E. coli DH10B, rivaling the efficiency of the wild-type tyrosine-incorporating Methanocaldococcus jannaschii orthogonal pair. The new orthogonal pair is deployed for the rapid evaluation of sense codon reassignment potential using our previously developed fluorescence-based screen. Measurements of sense codon reassignment efficiencies with the evolved M. barkeri machinery are compared with related measurements employing the M. jannaschii orthogonal pair system. Importantly, we observe different patterns of sense codon reassignment efficiency for the M. jannaschii tyrosyl and M. barkeri pyrrolysyl systems, suggesting that particular codons will be better suited to reassignment by different orthogonal pairs. A broad evaluation of sense codon reassignment efficiencies to tyrosine with the M. barkeri system will highlight the most promising positions at which the M. barkeri orthogonal pair may infiltrate the E. coli genetic code.
Collapse
Affiliation(s)
| | | | - John D. Fisk
- Department of Chemistry, University of Colorado Denver, Campus Box 194, P.O. Box 173364, Denver, CO 80217-3364, USA; (D.G.S.); (M.A.S.)
| |
Collapse
|
26
|
Singh T, Yadav SK, Vainstein A, Kumar V. Genome recoding strategies to improve cellular properties: mechanisms and advances. ABIOTECH 2021; 2:79-95. [PMID: 34377578 PMCID: PMC7675020 DOI: 10.1007/s42994-020-00030-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 10/07/2020] [Indexed: 11/10/2022]
Abstract
The genetic code, once believed to be universal and immutable, is now known to contain many variations and is not quite universal. The basis for genome recoding strategy is genetic code variation that can be harnessed to improve cellular properties. Thus, genome recoding is a promising strategy for the enhancement of genome flexibility, allowing for novel functions that are not commonly documented in the organism in its natural environment. Here, the basic concept of genetic code and associated mechanisms for the generation of genetic codon variants, including biased codon usage, codon reassignment, and ambiguous decoding, are extensively discussed. Knowledge of the concept of natural genetic code expansion is also detailed. The generation of recoded organisms and associated mechanisms with basic targeting components, including aminoacyl-tRNA synthetase-tRNA pairs, elongation factor EF-Tu and ribosomes, are highlighted for a comprehensive understanding of this concept. The research associated with the generation of diverse recoded organisms is also discussed. The success of genome recoding in diverse multicellular organisms offers a platform for expanding protein chemistry at the biochemical level with non-canonical amino acids, genetically isolating the synthetic organisms from the natural ones, and fighting viruses, including SARS-CoV2, through the creation of attenuated viruses. In conclusion, genome recoding can offer diverse applications for improving cellular properties in the genome-recoded organisms.
Collapse
Affiliation(s)
- Tanya Singh
- Department of Botany, School of Basic Sciences, Central University of Punjab, Bathinda, 151001 India
| | | | - Alexander Vainstein
- Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Vinay Kumar
- Department of Botany, School of Basic Sciences, Central University of Punjab, Bathinda, 151001 India
| |
Collapse
|
27
|
Chung CZ, Amikura K, Söll D. Using Genetic Code Expansion for Protein Biochemical Studies. Front Bioeng Biotechnol 2020; 8:598577. [PMID: 33195171 PMCID: PMC7604363 DOI: 10.3389/fbioe.2020.598577] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 09/29/2020] [Indexed: 01/31/2023] Open
Abstract
Protein identification has gone beyond simply using protein/peptide tags and labeling canonical amino acids. Genetic code expansion has allowed residue- or site-specific incorporation of non-canonical amino acids into proteins. By taking advantage of the unique properties of non-canonical amino acids, we can identify spatiotemporal-specific protein states within living cells. Insertion of more than one non-canonical amino acid allows for selective labeling that can aid in the identification of weak or transient protein-protein interactions. This review will discuss recent studies applying genetic code expansion for protein labeling and identifying protein-protein interactions and offer considerations for future work in expanding genetic code expansion methods.
Collapse
Affiliation(s)
- Christina Z. Chung
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
| | - Kazuaki Amikura
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
| | - Dieter Söll
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
- Department of Chemistry, Yale University, New Haven, CT, United States
| |
Collapse
|
28
|
Abstract
Preventing the escape of hazardous genes from genetically modified organisms (GMOs) into the environment is one of the most important issues in biotechnology research. Various strategies were developed to create "genetic firewalls" that prevent the leakage of GMOs; however, they were not specially designed to prevent the escape of genes. To address this issue, we developed amino acid (AA)-swapped genetic codes orthogonal to the standard genetic code, namely SL (Ser and Leu were swapped) and SLA genetic codes (Ser, Leu, and Ala were swapped). From mRNAs encoded by the AA-swapped genetic codes, functional proteins were only synthesized in translation systems featuring the corresponding genetic codes. These results clearly demonstrated the orthogonality of the AA-swapped genetic codes against the standard genetic code and their potential to function as "genetic firewalls for genes". Furthermore, we propose "a codon-bypass strategy" to develop a GMO with an AA-swapped genetic code.
Collapse
Affiliation(s)
- Tomoshige Fujino
- Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University, Nagoya, 464-8603, Japan
| | - Masahiro Tozaki
- Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University, Nagoya, 464-8603, Japan
| | - Hiroshi Murakami
- Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University, Nagoya, 464-8603, Japan
- Institute of Nano-Life-Systems, Institutes of Innovation for Future Society, Nagoya University, Nagoya, 464-8603, Japan
| |
Collapse
|
29
|
Tseng HW, Baumann T, Sun H, Wang YS, Ignatova Z, Budisa N. Expanding the Scope of Orthogonal Translation with Pyrrolysyl-tRNA Synthetases Dedicated to Aromatic Amino Acids. Molecules 2020; 25:E4418. [PMID: 32992991 PMCID: PMC7582959 DOI: 10.3390/molecules25194418] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/18/2020] [Accepted: 09/22/2020] [Indexed: 11/16/2022] Open
Abstract
In protein engineering and synthetic biology, Methanosarcina mazei pyrrolysyl-tRNA synthetase (MmPylRS), with its cognate tRNAPyl, is one of the most popular tools for site-specific incorporation of non-canonical amino acids (ncAAs). Numerous orthogonal pairs based on engineered MmPylRS variants have been developed during the last decade, enabling a substantial genetic code expansion, mainly with aliphatic pyrrolysine analogs. However, comparatively less progress has been made to expand the substrate range of MmPylRS towards aromatic amino acid residues. Therefore, we set to further expand the substrate scope of orthogonal translation by a semi-rational approach; redesigning the MmPylRS efficiency. Based on the randomization of residues from the binding pocket and tRNA binding domain, we identify three positions (V401, W417 and S193) crucial for ncAA specificity and enzyme activity. Their systematic mutagenesis enabled us to generate MmPylRS variants dedicated to tryptophan (such as β-(1-Azulenyl)-l-alanine or 1-methyl-l-tryptophan) and tyrosine (mainly halogenated) analogs. Moreover, our strategy also significantly improves the orthogonal translation efficiency with the previously activated analog 3-benzothienyl-l-alanine. Our study revealed the engineering of both first shell and distant residues to modify substrate specificity as an important strategy to further expand our ability to discover and recruit new ncAAs for orthogonal translation.
Collapse
Affiliation(s)
- Hsueh-Wei Tseng
- Institut für Chemie, Technische Universität Berlin, Müller-Breslau-Straße 10, 10623 Berlin, Germany; (H.-W.T.); (T.B.); (H.S.)
| | - Tobias Baumann
- Institut für Chemie, Technische Universität Berlin, Müller-Breslau-Straße 10, 10623 Berlin, Germany; (H.-W.T.); (T.B.); (H.S.)
| | - Huan Sun
- Institut für Chemie, Technische Universität Berlin, Müller-Breslau-Straße 10, 10623 Berlin, Germany; (H.-W.T.); (T.B.); (H.S.)
| | - Yane-Shih Wang
- Institute of Biological Chemistry, Academia Sinica, Taipei 116, Taiwan;
- Institute of Biochemical Sciences, National Taiwan University, Taipei 116, Taiwan
| | - Zoya Ignatova
- Institute of Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany;
| | - Nediljko Budisa
- Institut für Chemie, Technische Universität Berlin, Müller-Breslau-Straße 10, 10623 Berlin, Germany; (H.-W.T.); (T.B.); (H.S.)
- Department of Chemistry, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| |
Collapse
|
30
|
Ros E, Torres AG, Ribas de Pouplana L. Learning from Nature to Expand the Genetic Code. Trends Biotechnol 2020; 39:460-473. [PMID: 32896440 DOI: 10.1016/j.tibtech.2020.08.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 07/29/2020] [Accepted: 08/04/2020] [Indexed: 01/14/2023]
Abstract
The genetic code is the manual that cells use to incorporate amino acids into proteins. It is possible to artificially expand this manual through cellular, molecular, and chemical manipulations to improve protein functionality. Strategies for in vivo genetic code expansion are under the same functional constraints as natural protein synthesis. Here, we review the approaches used to incorporate noncanonical amino acids (ncAAs) into designer proteins through the manipulation of the translation machinery and draw parallels between these methods and natural adaptations that improve translation in extant organisms. Following this logic, we propose new nature-inspired tactics to improve genetic code expansion (GCE) in synthetic organisms.
Collapse
Affiliation(s)
- Enric Ros
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Catalonia, 08028, Spain
| | - Adrian Gabriel Torres
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Catalonia, 08028, Spain
| | - Lluís Ribas de Pouplana
- Institute for Research in Biomedicine, The Barcelona Institute of Science and Technology, Barcelona, Catalonia, 08028, Spain; Catalan Institution for Research and Advanced Studies, Barcelona, Catalonia, 08010, Spain.
| |
Collapse
|
31
|
Schwark DG, Schmitt MA, Biddle W, Fisk JD. The Influence of Competing tRNA Abundance on Translation: Quantifying the Efficiency of Sense Codon Reassignment at Rarely Used Codons. Chembiochem 2020; 21:2274-2286. [PMID: 32203635 DOI: 10.1002/cbic.202000052] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 03/12/2020] [Indexed: 11/07/2022]
Abstract
A quantitative understanding of how system composition and molecular properties conspire to determine the fidelity of translation is lacking. Our strategy directs an orthogonal tRNA to directly compete against endogenous tRNAs to decode individual targeted codons in a GFP reporter. Sets of directed sense codon reassignment measurements allow the isolation of particular factors contributing to translational fidelity. In this work, we isolated the effect of tRNA concentration on translational fidelity by evaluating reassignment of the 15 least commonly employed E. coli sense codons. Eight of the rarely used codons are reassigned with greater than 20 % efficiency. Both tRNA abundance and codon demand moderately inversely correlate with reassignment efficiency. Furthermore, the reassignment of rarely used codons does not appear to confer a fitness advantage relative to reassignment of other codons. These direct competition experiments also map potential targets for genetic code expansion. The isoleucine AUA codon is particularly attractive for the incorporation of noncanonical amino acids, with a nonoptimized reassignment efficiency of nearly 70 %.
Collapse
Affiliation(s)
- David G Schwark
- Department of Chemistry, University of Colorado Denver Campus Box 194, P.O. Box 173364, Denver, CO 80217-3364, USA
| | - Margaret A Schmitt
- Department of Chemistry, University of Colorado Denver Campus Box 194, P.O. Box 173364, Denver, CO 80217-3364, USA
| | - Wil Biddle
- Department of Chemistry, University of Colorado Denver Campus Box 194, P.O. Box 173364, Denver, CO 80217-3364, USA
| | - John D Fisk
- Department of Chemistry, University of Colorado Denver Campus Box 194, P.O. Box 173364, Denver, CO 80217-3364, USA
| |
Collapse
|
32
|
Jiang HK, Lee MN, Tsou JC, Chang KW, Tseng HW, Chen KP, Li YK, Wang YS. Linker and N-Terminal Domain Engineering of Pyrrolysyl-tRNA Synthetase for Substrate Range Shifting and Activity Enhancement. Front Bioeng Biotechnol 2020; 8:235. [PMID: 32322577 PMCID: PMC7156790 DOI: 10.3389/fbioe.2020.00235] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 03/06/2020] [Indexed: 12/16/2022] Open
Abstract
The Methanosarcina mazei pyrrolysyl-tRNA synthetase (PylRS)⋅tRNAPyl pair can be used to incorporate non-canonical amino acids (ncAAs) into proteins at installed amber stop codons. Although engineering of the PylRS active site generates diverse binding pockets, the substrate ranges are found similar in charging lysine and phenylalanine analogs. To expand the diversity of the ncAA side chains that can be incorporated via the PylRS⋅tRNAPyl pair, exploring remote interactions beyond the active site is an emerging approach in expanding the genetic code research. In this work, remote interactions between tRNAPyl, the tRNA binding domain of PylRS, and/or an introduced non-structured linker between the N- and C-terminus of PylRS were studied. The substrate range of the PylRS⋅tRNAPyl pair was visualized by producing sfGFP-UAG gene products, which also indicated amber suppression efficiencies and substrate specificity. The unstructured loop linking the N-terminal and C-terminal domains (CTDs) of PylRS has been suggested to regulate the interaction between PylRS and tRNAPyl. In exploring the detailed role of the loop region, different lengths of the linker were inserted into the junction between the N-terminal and the C-terminal domains of PylRS to unearth the impact on remote effects. Our findings suggest that the insertion of a moderate-length linker tunes the interface between PylRS and tRNAPyl and subsequently leads to improved suppression efficiencies. The suppression activity and the substrate specificity of PylRS were altered by introducing three mutations at or near the N-terminal domain of PylRS (N-PylRS). Using a N-PylRS⋅tRNAPyl pair, three ncAA substrates, two S-benzyl cysteine and a histidine analog, were incorporated into the protein site specifically.
Collapse
Affiliation(s)
- Han-Kai Jiang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.,Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan.,Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan
| | - Man-Nee Lee
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Jo-Chu Tsou
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Kuan-Wen Chang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Hsueh-Wei Tseng
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Kuang-Po Chen
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan
| | - Yaw-Kuen Li
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan
| | - Yane-Shih Wang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.,Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan.,Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| |
Collapse
|
33
|
Escherichia coli Extract-Based Cell-Free Expression System as an Alternative for Difficult-to-Obtain Protein Biosynthesis. Int J Mol Sci 2020; 21:ijms21030928. [PMID: 32023820 PMCID: PMC7037961 DOI: 10.3390/ijms21030928] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/15/2020] [Accepted: 01/28/2020] [Indexed: 12/15/2022] Open
Abstract
Before utilization in biomedical diagnosis, therapeutic treatment, and biotechnology, the diverse variety of peptides and proteins must be preliminarily purified and thoroughly characterized. The recombinant DNA technology and heterologous protein expression have helped simplify the isolation of targeted polypeptides at high purity and their structure-function examinations. Recombinant protein expression in Escherichia coli, the most-established heterologous host organism, has been widely used to produce proteins of commercial and fundamental research interests. Nonetheless, many peptides/proteins are still difficult to express due to their ability to slow down cell growth or disrupt cellular metabolism. Besides, special modifications are often required for proper folding and activity of targeted proteins. The cell-free (CF) or in vitro recombinant protein synthesis system enables the production of such difficult-to-obtain molecules since it is possible to adjust reaction medium and there is no need to support cellular metabolism and viability. Here, we describe E. coli-based CF systems, the optimization steps done toward the development of highly productive and cost-effective CF methodology, and the modification of an in vitro approach required for difficult-to-obtain protein production.
Collapse
|
34
|
Structure-guided design of pure orthosteric inhibitors of αIIbβ3 that prevent thrombosis but preserve hemostasis. Nat Commun 2020; 11:398. [PMID: 31964886 PMCID: PMC6972956 DOI: 10.1038/s41467-019-13928-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 12/06/2019] [Indexed: 02/07/2023] Open
Abstract
A prevailing dogma is that inhibition of vascular thrombosis by antagonizing platelet integrin αIIbβ3 cannot be achieved without compromising hemostasis, thus causing serious bleeding and increased morbidity and mortality. It is speculated that these adverse outcomes result from drug-induced activating conformational changes in αIIbβ3 but direct proof is lacking. Here, we report the structure-guided design of peptide Hr10 and a modified form of the partial agonist drug tirofiban that act as "pure" antagonists of αIIbβ3, i.e., they no longer induce the conformational changes in αIIbβ3. Both agents inhibit human platelet aggregation but preserve clot retraction. Hr10 and modified tirofiban are as effective as partial agonist drugs in inhibiting vascular thrombosis in humanized mice, but neither causes serious bleeding, establishing a causal link between partial agonism and impaired hemostasis. Pure orthosteric inhibitors of αIIbβ3 may thus provide safer alternatives for human therapy, and valuable tools to probe structure-activity relationships in integrins.
Collapse
|
35
|
Cui Z, Wu Y, Mureev S, Alexandrov K. Oligonucleotide-mediated tRNA sequestration enables one-pot sense codon reassignment in vitro. Nucleic Acids Res 2019; 46:6387-6400. [PMID: 29846683 PMCID: PMC6158751 DOI: 10.1093/nar/gky365] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 04/26/2018] [Indexed: 12/17/2022] Open
Abstract
Sense codon reassignment to unnatural amino acids (uAAs) represents a powerful approach for introducing novel properties into polypeptides. The main obstacle to this approach is competition between the native isoacceptor tRNA(s) and orthogonal tRNA(s) for the reassigned codon. While several chromatographic and enzymatic procedures for selective deactivation of tRNA isoacceptors in cell-free translation systems exist, they are complex and not scalable. We designed a set of tRNA antisense oligonucleotides composed of either deoxy-, ribo- or 2′-O-methyl ribonucleotides and tested their ability to efficiently complex tRNAs of choice. Methylated oligonucleotides targeting sequence between the anticodon and variable loop of tRNASerGCU displayed subnanomolar binding affinity with slow dissociation kinetics. Such oligonucleotides efficiently and selectively sequestered native tRNASerGCU directly in translation-competent Escherichia coli S30 lysate, thereby, abrogating its translational activity and liberating the AGU/AGC codons. Expression of eGFP protein from the template harboring a single reassignable AGU codon in tRNASerGCU-depleted E. coli lysate allowed its homogeneous modification with n-propargyl-l-lysine or p-azido-l-phenylalanine. The strategy developed here is generic, as demonstrated by sequestration of tRNAArgCCU isoacceptor in E. coli translation system. Furthermore, this method is likely to be species-independent and was successfully applied to the eukaryotic Leishmania tarentolae in vitro translation system. This approach represents a new direction in genetic code reassignment with numerous practical applications.
Collapse
Affiliation(s)
- Zhenling Cui
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Yue Wu
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Sergey Mureev
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Kirill Alexandrov
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia.,Australian Institute for Bioengeneering and Nanotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| |
Collapse
|
36
|
Smolskaya S, Andreev YA. Site-Specific Incorporation of Unnatural Amino Acids into Escherichia coli Recombinant Protein: Methodology Development and Recent Achievement. Biomolecules 2019; 9:biom9070255. [PMID: 31261745 PMCID: PMC6681230 DOI: 10.3390/biom9070255] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 06/21/2019] [Accepted: 06/25/2019] [Indexed: 12/13/2022] Open
Abstract
More than two decades ago a general method to genetically encode noncanonical or unnatural amino acids (NAAs) with diverse physical, chemical, or biological properties in bacteria, yeast, animals and mammalian cells was developed. More than 200 NAAs have been incorporated into recombinant proteins by means of non-endogenous aminoacyl-tRNA synthetase (aa-RS)/tRNA pair, an orthogonal pair, that directs site-specific incorporation of NAA encoded by a unique codon. The most established method to genetically encode NAAs in Escherichia coli is based on the usage of the desired mutant of Methanocaldococcus janaschii tyrosyl-tRNA synthetase (MjTyrRS) and cognate suppressor tRNA. The amber codon, the least-used stop codon in E. coli, assigns NAA. Until very recently the genetic code expansion technology suffered from a low yield of targeted proteins due to both incompatibilities of orthogonal pair with host cell translational machinery and the competition of suppressor tRNA with release factor (RF) for binding to nonsense codons. Here we describe the latest progress made to enhance nonsense suppression in E. coli with the emphasis on the improved expression vectors encoding for an orthogonal aa-RA/tRNA pair, enhancement of aa-RS and suppressor tRNA efficiency, the evolution of orthogonal EF-Tu and attempts to reduce the effect of RF1.
Collapse
Affiliation(s)
- Sviatlana Smolskaya
- Sechenov First Moscow State Medical University, Institute of Molecular Medicine, Trubetskaya str. 8, bld. 2, 119991 Moscow, Russia.
| | - Yaroslav A Andreev
- Sechenov First Moscow State Medical University, Institute of Molecular Medicine, Trubetskaya str. 8, bld. 2, 119991 Moscow, Russia.
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia.
| |
Collapse
|
37
|
Fredens J, Wang K, de la Torre D, Funke LFH, Robertson WE, Christova Y, Chia T, Schmied WH, Dunkelmann DL, Beránek V, Uttamapinant C, Llamazares AG, Elliott TS, Chin JW. Total synthesis of Escherichia coli with a recoded genome. Nature 2019; 569:514-518. [PMID: 31092918 DOI: 10.1038/s41586-019-1192-5] [Citation(s) in RCA: 281] [Impact Index Per Article: 56.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 04/09/2019] [Indexed: 11/09/2022]
Abstract
Nature uses 64 codons to encode the synthesis of proteins from the genome, and chooses 1 sense codon-out of up to 6 synonyms-to encode each amino acid. Synonymous codon choice has diverse and important roles, and many synonymous substitutions are detrimental. Here we demonstrate that the number of codons used to encode the canonical amino acids can be reduced, through the genome-wide substitution of target codons by defined synonyms. We create a variant of Escherichia coli with a four-megabase synthetic genome through a high-fidelity convergent total synthesis. Our synthetic genome implements a defined recoding and refactoring scheme-with simple corrections at just seven positions-to replace every known occurrence of two sense codons and a stop codon in the genome. Thus, we recode 18,214 codons to create an organism with a 61-codon genome; this organism uses 59 codons to encode the 20 amino acids, and enables the deletion of a previously essential transfer RNA.
Collapse
Affiliation(s)
- Julius Fredens
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
| | - Kaihang Wang
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK.,Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | | | - Louise F H Funke
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
| | | | - Yonka Christova
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
| | - Tiongsun Chia
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
| | | | | | - Václav Beránek
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
| | - Chayasith Uttamapinant
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK.,School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, Thailand
| | | | - Thomas S Elliott
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK
| | - Jason W Chin
- Medical Research Council Laboratory of Molecular Biology, Cambridge, UK.
| |
Collapse
|
38
|
Alternative Biochemistries for Alien Life: Basic Concepts and Requirements for the Design of a Robust Biocontainment System in Genetic Isolation. Genes (Basel) 2018; 10:genes10010017. [PMID: 30597824 PMCID: PMC6356944 DOI: 10.3390/genes10010017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 12/21/2018] [Accepted: 12/21/2018] [Indexed: 02/08/2023] Open
Abstract
The universal genetic code, which is the foundation of cellular organization for almost all organisms, has fostered the exchange of genetic information from very different paths of evolution. The result of this communication network of potentially beneficial traits can be observed as modern biodiversity. Today, the genetic modification techniques of synthetic biology allow for the design of specialized organisms and their employment as tools, creating an artificial biodiversity based on the same universal genetic code. As there is no natural barrier towards the proliferation of genetic information which confers an advantage for a certain species, the naturally evolved genetic pool could be irreversibly altered if modified genetic information is exchanged. We argue that an alien genetic code which is incompatible with nature is likely to assure the inhibition of all mechanisms of genetic information transfer in an open environment. The two conceivable routes to synthetic life are either de novo cellular design or the successive alienation of a complex biological organism through laboratory evolution. Here, we present the strategies that have been utilized to fundamentally alter the genetic code in its decoding rules or its molecular representation and anticipate future avenues in the pursuit of robust biocontainment.
Collapse
|
39
|
Versatility of Synthetic tRNAs in Genetic Code Expansion. Genes (Basel) 2018; 9:genes9110537. [PMID: 30405060 PMCID: PMC6267555 DOI: 10.3390/genes9110537] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 10/31/2018] [Accepted: 11/05/2018] [Indexed: 12/16/2022] Open
Abstract
Transfer RNA (tRNA) is a dynamic molecule used by all forms of life as a key component of the translation apparatus. Each tRNA is highly processed, structured, and modified, to accurately deliver amino acids to the ribosome for protein synthesis. The tRNA molecule is a critical component in synthetic biology methods for the synthesis of proteins designed to contain non-canonical amino acids (ncAAs). The multiple interactions and maturation requirements of a tRNA pose engineering challenges, but also offer tunable features. Major advances in the field of genetic code expansion have repeatedly demonstrated the central importance of suppressor tRNAs for efficient incorporation of ncAAs. Here we review the current status of two fundamentally different translation systems (TSs), selenocysteine (Sec)- and pyrrolysine (Pyl)-TSs. Idiosyncratic requirements of each of these TSs mandate how their tRNAs are adapted and dictate the techniques used to select or identify the best synthetic variants.
Collapse
|
40
|
Vargas-Rodriguez O, Sevostyanova A, Söll D, Crnković A. Upgrading aminoacyl-tRNA synthetases for genetic code expansion. Curr Opin Chem Biol 2018; 46:115-122. [PMID: 30059834 PMCID: PMC6214156 DOI: 10.1016/j.cbpa.2018.07.014] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 05/04/2018] [Accepted: 07/13/2018] [Indexed: 01/06/2023]
Abstract
Synthesis of proteins with non-canonical amino acids via genetic code expansion is at the forefront of synthetic biology. Progress in this field has enabled site-specific incorporation of over 200 chemically and structurally diverse amino acids into proteins in an increasing number of organisms. This has been facilitated by our ability to repurpose aminoacyl-tRNA synthetases to attach non-canonical amino acids to engineered tRNAs. Current efforts in the field focus on overcoming existing limitations to the simultaneous incorporation of multiple non-canonical amino acids or amino acids that differ from the l-α-amino acid structure (e.g. d-amino acid or β-amino acid). Here, we summarize the progress and challenges in developing more selective and efficient aminoacyl-tRNA synthetases for genetic code expansion.
Collapse
Affiliation(s)
- Oscar Vargas-Rodriguez
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA.
| | - Anastasia Sevostyanova
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
| | - Dieter Söll
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA; Department of Chemistry, Yale University, New Haven, CT 06520, USA
| | - Ana Crnković
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA.
| |
Collapse
|
41
|
Ohtake K, Mukai T, Iraha F, Takahashi M, Haruna KI, Date M, Yokoyama K, Sakamoto K. Engineering an Automaturing Transglutaminase with Enhanced Thermostability by Genetic Code Expansion with Two Codon Reassignments. ACS Synth Biol 2018; 7:2170-2176. [PMID: 30063837 DOI: 10.1021/acssynbio.8b00157] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In the present study, we simultaneously incorporated two types of synthetic components into microbial transglutaminase (MTG) from Streptoverticillium mobaraense to enhance the utility of this industrial enzyme. The first amino acid, 3-chloro-l-tyrosine, was incorporated into MTG in response to in-frame UAG codons to substitute for the 15 tyrosine residues separately. The two substitutions at positions 20 and 62 were found to each increase thermostability of the enzyme, while the seven substitutions at positions 24, 34, 75, 146, 171, 217, and 310 exhibited neutral effects. Then, these two stabilizing chlorinations were combined with one of the neutral ones, and the most stabilized variant was found to contain 3-chlorotyrosines at positions 20, 62, and 171, exhibiting a half-life 5.1-fold longer than that of the wild-type enzyme at 60 °C. Next, this MTG variant was further modified by incorporating the α-hydroxy acid analogue of Nε-allyloxycarbonyl-l-lysine (AlocKOH), specified by the AGG codon, at the end of the N-terminal inhibitory peptide. We used an Escherichia coli strain previously engineered to have a synthetic genetic code with two codon reassignments for synthesizing MTG variants containing both 3-chlorotyrosine and AlocKOH. The ester bond, thus incorporated into the main chain, efficiently self-cleaved under alkaline conditions (pH 11.0), achieving the autonomous maturation of the thermostabilized MTG. The results suggested that synthetic genetic codes with multiple codon reassignments would be useful for developing the novel designs of enzymes.
Collapse
Affiliation(s)
| | | | | | | | - Ken-ichi Haruna
- Institute for Innovation, Ajinomoto Co., Inc., 1-1 Suzuki-cho, Kawasaki-ku, Kawasaki 210-8681, Japan
| | - Masayo Date
- Institute for Innovation, Ajinomoto Co., Inc., 1-1 Suzuki-cho, Kawasaki-ku, Kawasaki 210-8681, Japan
| | - Keiichi Yokoyama
- Institute for Innovation, Ajinomoto Co., Inc., 1-1 Suzuki-cho, Kawasaki-ku, Kawasaki 210-8681, Japan
| | | |
Collapse
|
42
|
Whitford CM, Dymek S, Kerkhoff D, März C, Schmidt O, Edich M, Droste J, Pucker B, Rückert C, Kalinowski J. Auxotrophy to Xeno-DNA: an exploration of combinatorial mechanisms for a high-fidelity biosafety system for synthetic biology applications. J Biol Eng 2018; 12:13. [PMID: 30123321 PMCID: PMC6090650 DOI: 10.1186/s13036-018-0105-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 06/25/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Biosafety is a key aspect in the international Genetically Engineered Machine (iGEM) competition, which offers student teams an amazing opportunity to pursue their own research projects in the field of Synthetic Biology. iGEM projects often involve the creation of genetically engineered bacterial strains. To minimize the risks associated with bacterial release, a variety of biosafety systems were constructed, either to prevent survival of bacteria outside the lab or to hinder horizontal or vertical gene transfer. MAIN BODY Physical containment methods such as bioreactors or microencapsulation are considered the first safety level. Additionally, various systems involving auxotrophies for both natural and synthetic compounds have been utilized by iGEM teams in recent years. Combinatorial systems comprising multiple auxotrophies have been shown to reduced escape frequencies below the detection limit. Furthermore, a number of natural toxin-antitoxin systems can be deployed to kill cells under certain conditions. Additionally, parts of naturally occurring toxin-antitoxin systems can be used for the construction of 'kill switches' controlled by synthetic regulatory modules, allowing control of cell survival. Kill switches prevent cell survival but do not completely degrade nucleic acids. To avoid horizontal gene transfer, multiple mechanisms to cleave nucleic acids can be employed, resulting in 'self-destruction' of cells. Changes in light or temperature conditions are powerful regulators of gene expression and could serve as triggers for kill switches or self-destruction systems. Xenobiology-based containment uses applications of Xeno-DNA, recoded codons and non-canonical amino acids to nullify the genetic information of constructed cells for wild type organisms. A 'minimal genome' approach brings the opportunity to reduce the genome of a cell to only genes necessary for survival under lab conditions. Such cells are unlikely to survive in the natural environment and are thus considered safe hosts. If suitable for the desired application, a shift to cell-free systems based on Xeno-DNA may represent the ultimate biosafety system. CONCLUSION Here we describe different containment approaches in synthetic biology, ranging from auxotrophies to minimal genomes, which can be combined to significantly improve reliability. Since the iGEM competition greatly increases the number of people involved in synthetic biology, we will focus especially on biosafety systems developed and applied in the context of the iGEM competition.
Collapse
Affiliation(s)
| | - Saskia Dymek
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
| | - Denise Kerkhoff
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
| | - Camilla März
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
| | - Olga Schmidt
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
| | - Maximilian Edich
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
| | - Julian Droste
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
- Faculty of Biology, Bielefeld University, Bielefeld, Germany
| | - Boas Pucker
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
- Faculty of Biology, Bielefeld University, Bielefeld, Germany
- Present address: Evolution and Diversity, Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Christian Rückert
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
- Faculty of Biology, Bielefeld University, Bielefeld, Germany
| | - Jörn Kalinowski
- Center for Biotechnology, Bielefeld University, 33615 Bielefeld, Germany
- Faculty of Biology, Bielefeld University, Bielefeld, Germany
| |
Collapse
|
43
|
Schmitt MA, Biddle W, Fisk JD. Mapping the Plasticity of the Escherichia coli Genetic Code with Orthogonal Pair-Directed Sense Codon Reassignment. Biochemistry 2018; 57:2762-2774. [PMID: 29668270 DOI: 10.1021/acs.biochem.8b00177] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The relative quantitative importance of the factors that determine the fidelity of translation is largely unknown, which makes predicting the extent to which the degeneracy of the genetic code can be broken challenging. Our strategy of using orthogonal tRNA/aminoacyl tRNA synthetase pairs to precisely direct the incorporation of a single amino acid in response to individual sense and nonsense codons provides a suite of related data with which to examine the plasticity of the code. Each directed sense codon reassignment measurement is an in vivo competition experiment between the introduced orthogonal translation machinery and the natural machinery in Escherichia coli. This report discusses 20 new, related genetic codes, in which a targeted E. coli wobble codon is reassigned to tyrosine utilizing the orthogonal tyrosine tRNA/aminoacyl tRNA synthetase pair from Methanocaldococcus jannaschii. One at a time, reassignment of each targeted sense codon to tyrosine is quantified in cells by measuring the fluorescence of GFP variants in which the essential tyrosine residue is encoded by a non-tyrosine codon. Significantly, every wobble codon analyzed may be partially reassigned with efficiencies ranging from 0.8 to 41%. The accumulation of the suite of data enables a qualitative dissection of the relative importance of the factors affecting the fidelity of translation. While some correlation was observed between sense codon reassignment and either competing endogenous tRNA abundance or changes in aminoacylation efficiency of the altered orthogonal system, no single factor appears to predominately drive translational fidelity. Evaluation of relative cellular fitness in each of the 20 quantitatively characterized proteome-wide tyrosine substitution systems suggests that at a systems level, E. coli is robust to missense mutations.
Collapse
Affiliation(s)
- Margaret A Schmitt
- Department of Chemical and Biological Engineering , Colorado State University , Fort Collins , Colorado 80523 , United States
| | - Wil Biddle
- Department of Chemistry , Colorado State University , Fort Collins , Colorado 80523 , United States
| | - John D Fisk
- Department of Chemical and Biological Engineering , Colorado State University , Fort Collins , Colorado 80523 , United States.,Department of Chemistry , Colorado State University , Fort Collins , Colorado 80523 , United States.,School of Biomedical Engineering , Colorado State University , Fort Collins , Colorado 80523 , United States
| |
Collapse
|
44
|
Abstract
Pyrrolysine is the 22nd proteinogenic amino acid encoded into proteins in response to amber (TAG) codons in a small number of archaea and bacteria. The incorporation of pyrrolysine is facilitated by a specialized aminoacyl-tRNA synthetase (PylRS) and its cognate tRNA (tRNAPyl). The secondary structure of tRNAPyl contains several unique features not found in canonical tRNAs. Numerous studies have demonstrated that the PylRS/tRNAPyl pair from archaea is orthogonal in E. coli and eukaryotic hosts, which has led to the widespread use of this pair for the genetic incorporation of non-canonical amino acids. In this brief review we examine the work that has been done to elucidate the structure of tRNAPyl, its interaction with PylRS, and survey recent progress on the use of tRNAPyl as a tool for genetic code expansion.
Collapse
Affiliation(s)
- Jeffery M Tharp
- a Department of Chemistry , Texas A&M University , College Station , TX , USA
| | - Andreas Ehnbom
- a Department of Chemistry , Texas A&M University , College Station , TX , USA
| | - Wenshe R Liu
- a Department of Chemistry , Texas A&M University , College Station , TX , USA
| |
Collapse
|
45
|
Abstract
The genetic code-the language used by cells to translate their genomes into proteins that perform many cellular functions-is highly conserved throughout natural life. Rewriting the genetic code could lead to new biological functions such as expanding protein chemistries with noncanonical amino acids (ncAAs) and genetically isolating synthetic organisms from natural organisms and viruses. It has long been possible to transiently produce proteins bearing ncAAs, but stabilizing an expanded genetic code for sustained function in vivo requires an integrated approach: creating recoded genomes and introducing new translation machinery that function together without compromising viability or clashing with endogenous pathways. In this review, we discuss design considerations and technologies for expanding the genetic code. The knowledge obtained by rewriting the genetic code will deepen our understanding of how genomes are designed and how the canonical genetic code evolved.
Collapse
Affiliation(s)
- Takahito Mukai
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511;
| | - Marc J Lajoie
- Department of Biochemistry, University of Washington, Seattle, Washington 98195
| | - Markus Englert
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511;
| | - Dieter Söll
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511; .,Department of Chemistry, Yale University, New Haven, Connecticut 06511
| |
Collapse
|
46
|
Salehi ASM, Smith MT, Schinn S, Hunt JM, Muhlestein C, Diray‐Arce J, Nielsen BL, Bundy BC. Efficient t
RNA
degradation and quantification in
Escherichia coli
cell extract using R
N
ase‐coated magnetic beads: A key step toward codon emancipation. Biotechnol Prog 2017; 33:1401-1407. [DOI: 10.1002/btpr.2511] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 06/03/2017] [Indexed: 01/14/2023]
Affiliation(s)
- Amin S. M. Salehi
- Department of Chemical EngineeringBrigham Young UniversityProvo UT84602
| | - Mark T. Smith
- Department of Chemical EngineeringBrigham Young UniversityProvo UT84602
| | - Song‐Min Schinn
- Department of Chemical EngineeringBrigham Young UniversityProvo UT84602
| | - Jeremy M. Hunt
- Department of Chemical EngineeringBrigham Young UniversityProvo UT84602
| | | | - Joann Diray‐Arce
- Department of Microbiology & Molecular BiologyBrigham Young UniversityProvo UT84602
| | - Brent L. Nielsen
- Department of Microbiology & Molecular BiologyBrigham Young UniversityProvo UT84602
| | - Bradley C. Bundy
- Department of Chemical EngineeringBrigham Young UniversityProvo UT84602
| |
Collapse
|
47
|
Cui Z, Mureev S, Polinkovsky ME, Tnimov Z, Guo Z, Durek T, Jones A, Alexandrov K. Combining Sense and Nonsense Codon Reassignment for Site-Selective Protein Modification with Unnatural Amino Acids. ACS Synth Biol 2017; 6:535-544. [PMID: 27966891 DOI: 10.1021/acssynbio.6b00245] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Incorporation of unnatural amino acids (uAAs) via codon reassignment is a powerful approach for introducing novel chemical and biological properties to synthesized polypeptides. However, the site-selective incorporation of multiple uAAs into polypeptides is hampered by the limited number of reassignable nonsense codons. This challenge is addressed in the current work by developing Escherichia coli in vitro translation system depleted of specific endogenous tRNAs. The translational activity in this system is dependent on the addition of synthetic tRNAs for the chosen sense codon. This allows site-selective uAA incorporation via addition of tRNAs pre- or cotranslationally charged with uAA. We demonstrate the utility of this system by incorporating the BODIPY fluorophore into the unique AGG codon of the calmodulin(CaM) open reading frame using in vitro precharged BODIPY-tRNACysCCU. The deacylated tRNACysCCU is a poor substrate for Cysteinyl-tRNA synthetase, which ensures low background incorporation of Cys into the chosen codon. Simultaneously, p-azidophenylalanine mediated amber-codon suppression and its post-translational conjugation to tetramethylrhodamine dibenzocyclooctyne (TAMRA-DIBO) were performed on the same polypeptide. This simple and robust approach takes advantage of the compatibility of BODIPY fluorophore with the translational machinery and thus requires only one post-translational derivatization step to introduce two fluorescent labels. Using this approach, we obtained CaM nearly homogeneously labeled with two FRET-forming fluorophores. Single molecule FRET analysis revealed dramatic changes in the conformation of the CaM probe upon its exposure to Ca2+ or a chelating agent. The presented approach is applicable to other sense codons and can be directly transferred to eukaryotic cell-free systems.
Collapse
Affiliation(s)
- Zhenling Cui
- Institute
for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Sergey Mureev
- Institute
for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Mark E. Polinkovsky
- StemProtein, 6350 Nancy
Ridge Drive, San Diego, California 92121, United States
| | - Zakir Tnimov
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, United Kingdom
| | - Zhong Guo
- Institute
for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Thomas Durek
- Institute
for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Alun Jones
- Institute
for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Kirill Alexandrov
- Institute
for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia
| |
Collapse
|
48
|
Lin X, Yu ACS, Chan TF. Efforts and Challenges in Engineering the Genetic Code. Life (Basel) 2017; 7:life7010012. [PMID: 28335420 PMCID: PMC5370412 DOI: 10.3390/life7010012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 03/09/2017] [Accepted: 03/10/2017] [Indexed: 12/15/2022] Open
Abstract
This year marks the 48th anniversary of Francis Crick’s seminal work on the origin of the genetic code, in which he first proposed the “frozen accident” hypothesis to describe evolutionary selection against changes to the genetic code that cause devastating global proteome modification. However, numerous efforts have demonstrated the viability of both natural and artificial genetic code variations. Recent advances in genetic engineering allow the creation of synthetic organisms that incorporate noncanonical, or even unnatural, amino acids into the proteome. Currently, successful genetic code engineering is mainly achieved by creating orthogonal aminoacyl-tRNA/synthetase pairs to repurpose stop and rare codons or to induce quadruplet codons. In this review, we summarize the current progress in genetic code engineering and discuss the challenges, current understanding, and future perspectives regarding genetic code modification.
Collapse
Affiliation(s)
- Xiao Lin
- School of Life Sciences, The Chinese University of Hong Kong, Sha Tin, NT, Hong Kong, China.
| | - Allen Chi Shing Yu
- School of Life Sciences, The Chinese University of Hong Kong, Sha Tin, NT, Hong Kong, China.
| | - Ting Fung Chan
- School of Life Sciences, The Chinese University of Hong Kong, Sha Tin, NT, Hong Kong, China.
| |
Collapse
|
49
|
Future of the Genetic Code. Life (Basel) 2017; 7:life7010010. [PMID: 28264473 PMCID: PMC5370410 DOI: 10.3390/life7010010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 02/20/2017] [Accepted: 02/23/2017] [Indexed: 11/17/2022] Open
Abstract
The methods for establishing synthetic lifeforms with rewritten genetic codes comprising non-canonical amino acids (NCAA) in addition to canonical amino acids (CAA) include proteome-wide replacement of CAA, insertion through suppression of nonsense codon, and insertion via the pyrrolysine and selenocysteine pathways. Proteome-wide reassignments of nonsense codons and sense codons are also under development. These methods enable the application of NCAAs to enrich both fundamental and applied aspects of protein chemistry and biology. Sense codon reassignment to NCAA could incur problems arising from the usage of anticodons as identity elements on tRNA, and possible misreading of NNY codons by UNN anticodons. Evidence suggests that the problem of anticodons as identity elements can be diminished or resolved through removal from the tRNA of all identity elements besides the anticodon, and the problem of misreading of NNY codons by UNN anticodon can be resolved by the retirement of both the UNN anticodon and its complementary NNA codon from the proteome in the event that a restrictive post-transcriptional modification of the UNN anticodon by host enzymes to prevent the misreading cannot be obtained.
Collapse
|
50
|
Völler JS, Biava H, Hildebrandt P, Budisa N. An expanded genetic code for probing the role of electrostatics in enzyme catalysis by vibrational Stark spectroscopy. Biochim Biophys Acta Gen Subj 2017; 1861:3053-3059. [PMID: 28229928 DOI: 10.1016/j.bbagen.2017.02.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 02/03/2017] [Indexed: 11/28/2022]
Abstract
BACKGROUND To find experimental validation for electrostatic interactions essential for catalytic reactions represents a challenge due to practical limitations in assessing electric fields within protein structures. SCOPE OF REVIEW This review examines the applications of non-canonical amino acids (ncAAs) as genetically encoded probes for studying the role of electrostatic interactions in enzyme catalysis. MAJOR CONCLUSIONS ncAAs constitute sensitive spectroscopic probes to detect local electric fields by exploiting the vibrational Stark effect (VSE) and thus have the potential to map the protein electrostatics. GENERAL SIGNIFICANCE Mapping the electrostatics in proteins will improve our understanding of natural catalytic processes and, in beyond, will be helpful for biocatalyst engineering. This article is part of a Special Issue entitled "Biochemistry of Synthetic Biology - Recent Developments" Guest Editor: Dr. Ilka Heinemann and Dr. Patrick O'Donoghue.
Collapse
Affiliation(s)
- Jan-Stefan Völler
- Department of Chemistry, Technische Universität Berlin, Müller-Breslau-Strasse 10, D-10623 Berlin, Germany.
| | - Hernan Biava
- Department of Chemistry, Technische Universität Berlin, Müller-Breslau-Strasse 10, D-10623 Berlin, Germany; Department of Chemistry, Technische Universität Berlin, Straße des 17. Juni 135, D-10623 Berlin, Germany
| | - Peter Hildebrandt
- Department of Chemistry, Technische Universität Berlin, Straße des 17. Juni 135, D-10623 Berlin, Germany.
| | - Nediljko Budisa
- Department of Chemistry, Technische Universität Berlin, Müller-Breslau-Strasse 10, D-10623 Berlin, Germany.
| |
Collapse
|