1
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Perez LJ, Cloherty GA, Berg MG. Parallel evolution of picobirnaviruses from distinct ancestral origins. Microbiol Spectr 2023; 11:e0269323. [PMID: 37888988 PMCID: PMC10714727 DOI: 10.1128/spectrum.02693-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 09/19/2023] [Indexed: 10/28/2023] Open
Abstract
IMPORTANCE Picobirnaviruses (PBVs) are highly heterogeneous viruses encoding a capsid and RdRp. Detected in a wide variety of animals with and without disease, their association with gastrointestinal and respiratory infections, and consequently their public health importance, has rightly been questioned. Determining the "true" host of Picobirnavirus lies at the center of this debate, as evidence exists for them having both vertebrate and prokaryotic origins. Using integrated and time-stamped phylogenetic approaches, we show they are contemporaneous viruses descending from two different ancestors: avian Reovirus and fungal Partitivirus. The fungal PBV-R2 species emerged with a single segment (RdRp) until it acquired a capsid from vertebrate PBV-R1 and PBV-R3 species. Protein and RNA folding analyses revealed how the former came to resemble the latter over time. Thus, parallel evolution from disparate hosts has driven the adaptation and genetic diversification of the Picobirnaviridae family.
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Affiliation(s)
- Lester J. Perez
- Infectious Disease Core Research, Abbott Diagnostics Division, Abbott Laboratories, Abbott Park, Illinois, USA
- Abbott Pandemic Defense Coalition (APDC), Chicago, Illinois, USA
| | - Gavin A. Cloherty
- Infectious Disease Core Research, Abbott Diagnostics Division, Abbott Laboratories, Abbott Park, Illinois, USA
- Abbott Pandemic Defense Coalition (APDC), Chicago, Illinois, USA
| | - Michael G. Berg
- Infectious Disease Core Research, Abbott Diagnostics Division, Abbott Laboratories, Abbott Park, Illinois, USA
- Abbott Pandemic Defense Coalition (APDC), Chicago, Illinois, USA
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2
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Ghosh A, Bharmal MHM, Ghaleb AM, Nandana V, Schrader JM. Initiator AUGs Are Discriminated from Elongator AUGs Predominantly through mRNA Accessibility in C. crescentus. J Bacteriol 2023; 205:e0042022. [PMID: 37092987 PMCID: PMC10210977 DOI: 10.1128/jb.00420-22] [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: 11/05/2022] [Accepted: 03/27/2023] [Indexed: 04/25/2023] Open
Abstract
The initiation of translation in bacteria is thought to occur upon base pairing between the Shine-Dalgarno (SD) site in the mRNA and the anti-SD site in the rRNA. However, in many bacterial species, such as Caulobacter crescentus, a minority of mRNAs have SD sites. To examine the functional importance of SD sites in C. crescentus, we analyzed the transcriptome and found that more SD sites exist in the coding sequence than in the preceding start codons. To examine the function of SD sites in initiation, we designed a series of mutants with altered ribosome accessibility and SD content in translation initiation regions (TIRs) and in elongator AUG regions (EARs). A lack of mRNA structure content is required for initiation in TIRs, and, when introduced into EARs, can stimulate initiation, thereby suggesting that low mRNA structure content is a major feature that is required for initiation. SD sites appear to stimulate initiation in TIRs, which generally lack structure content, but SD sites only stimulate initiation in EARs if RNA secondary structures are destabilized. Taken together, these results suggest that the difference in secondary structure between TIRs and EARs directs ribosomes to start codons where SD base pairing can tune the efficiency of initiation, but SDs in EARs do not stimulate initiation, as they are blocked by stable secondary structures. This highlights the importance of studying translation initiation mechanisms in diverse bacterial species. IMPORTANCE Start codon selection is an essential process that is thought to occur via the base pairing of the rRNA to the SD site in the mRNA. This model is based on studies in E. coli, yet whole-genome sequencing revealed that SD sites are absent at start codons in many species. By examining the transcriptome of C. crescentus, we found more SD-AUG pairs in the CDS of mRNAs than preceding start codons, yet these internal sites do not initiate. Instead, start codon regions have lower mRNA secondary structure content than do internal SD-AUG regions. Therefore, we find that start codon selection is not controlled by the presence of SD sites, which tune initiation efficiency, but by lower mRNA structure content surrounding the start codon.
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Affiliation(s)
- Aishwarya Ghosh
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | | | - Amar M. Ghaleb
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Vidhyadhar Nandana
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Jared M. Schrader
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
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3
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Zabolotskii AI, Kozlovskiy SV, Katrukha AG. The Influence of the Nucleotide Composition of Genes and Gene Regulatory Elements on the Efficiency of Protein Expression in Escherichia coli. BIOCHEMISTRY (MOSCOW) 2023; 88:S176-S191. [PMID: 37069120 DOI: 10.1134/s0006297923140109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Recombinant proteins expressed in Escherichia coli are widely used in biochemical research and industrial processes. At the same time, achieving higher protein expression levels and correct protein folding still remains the key problem, since optimization of nutrient media, growth conditions, and methods for induction of protein synthesis do not always lead to the desired result. Often, low protein expression is determined by the sequences of the expressed genes and their regulatory regions. The genetic code is degenerated; 18 out of 20 amino acids are encoded by more than one codon. Choosing between synonymous codons in the coding sequence can significantly affect the level of protein expression and protein folding due to the influence of the gene nucleotide composition on the probability of formation of secondary mRNA structures that affect the ribosome binding at the translation initiation phase, as well as the ribosome movement along the mRNA during elongation, which, in turn, influences the mRNA degradation and the folding of the nascent protein. The nucleotide composition of the mRNA untranslated regions, in particular the promoter and Shine-Dalgarno sequences, also affects the efficiency of mRNA transcription, translation, and degradation. In this review, we describe the genetic principles that determine the efficiency of protein production in Escherichia coli.
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Affiliation(s)
- Artur I Zabolotskii
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
| | | | - Alexey G Katrukha
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
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4
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Neri U, Wolf YI, Roux S, Camargo AP, Lee B, Kazlauskas D, Chen IM, Ivanova N, Zeigler Allen L, Paez-Espino D, Bryant DA, Bhaya D, Krupovic M, Dolja VV, Kyrpides NC, Koonin EV, Gophna U. Expansion of the global RNA virome reveals diverse clades of bacteriophages. Cell 2022; 185:4023-4037.e18. [PMID: 36174579 DOI: 10.1016/j.cell.2022.08.023] [Citation(s) in RCA: 85] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 05/16/2022] [Accepted: 08/24/2022] [Indexed: 01/26/2023]
Abstract
High-throughput RNA sequencing offers broad opportunities to explore the Earth RNA virome. Mining 5,150 diverse metatranscriptomes uncovered >2.5 million RNA virus contigs. Analysis of >330,000 RNA-dependent RNA polymerases (RdRPs) shows that this expansion corresponds to a 5-fold increase of the known RNA virus diversity. Gene content analysis revealed multiple protein domains previously not found in RNA viruses and implicated in virus-host interactions. Extended RdRP phylogeny supports the monophyly of the five established phyla and reveals two putative additional bacteriophage phyla and numerous putative additional classes and orders. The dramatically expanded phylum Lenarviricota, consisting of bacterial and related eukaryotic viruses, now accounts for a third of the RNA virome. Identification of CRISPR spacer matches and bacteriolytic proteins suggests that subsets of picobirnaviruses and partitiviruses, previously associated with eukaryotes, infect prokaryotic hosts.
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Affiliation(s)
- Uri Neri
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Tel Aviv 6997801, Israel.
| | - Yuri I Wolf
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Simon Roux
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Antonio Pedro Camargo
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Benjamin Lee
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA; Nuffield Department of Medicine, University of Oxford, Oxford OX3 7BN, UK
| | - Darius Kazlauskas
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Saulėtekio av. 7, Vilnius 10257, Lithuania
| | - I Min Chen
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Natalia Ivanova
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Lisa Zeigler Allen
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, CA, USA; Marine Biology Research Division, Scripps Institution of Oceanography, La Jolla, CA, USA
| | - David Paez-Espino
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Donald A Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Devaki Bhaya
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Mart Krupovic
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Archaeal Virology Unit, 75015 Paris, France
| | - Valerian V Dolja
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA; Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA.
| | - Nikos C Kyrpides
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA.
| | - Uri Gophna
- The Shmunis School of Biomedicine and Cancer Research, Tel Aviv University, Tel Aviv 6997801, Israel.
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Shah SB, Hill AM, Wilke CO, Hockenberry AJ. Generating dynamic gene expression patterns without the need for regulatory circuits. PLoS One 2022; 17:e0268883. [PMID: 35617346 PMCID: PMC9135205 DOI: 10.1371/journal.pone.0268883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 05/10/2022] [Indexed: 11/18/2022] Open
Abstract
Synthetic biology has successfully advanced our ability to design and implement complex, time-varying genetic circuits to control the expression of recombinant proteins. However, these circuits typically require the production of regulatory genes whose only purpose is to coordinate expression of other genes. When designing very small genetic constructs, such as viral genomes, we may want to avoid introducing such auxiliary gene products while nevertheless encoding complex expression dynamics. To this end, here we demonstrate that varying only the placement and strengths of promoters, terminators, and RNase cleavage sites in a computational model of a bacteriophage genome is sufficient to achieve solutions to a variety of basic gene expression patterns. We discover these genetic solutions by computationally evolving genomes to reproduce desired gene expression time-course data. Our approach shows that non-trivial patterns can be evolved, including patterns where the relative ordering of genes by abundance changes over time. We find that some patterns are easier to evolve than others, and comparable expression patterns can be achieved via different genetic architectures. Our work opens up a novel avenue to genome engineering via fine-tuning the balance of gene expression and gene degradation rates.
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Affiliation(s)
- Sahil B. Shah
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX, United States of America
| | - Alexis M. Hill
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX, United States of America
| | - Claus O. Wilke
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX, United States of America
- * E-mail: (COW); (AJH)
| | - Adam J. Hockenberry
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX, United States of America
- * E-mail: (COW); (AJH)
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6
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Bahiri Elitzur S, Cohen-Kupiec R, Yacobi D, Fine L, Apt B, Diament A, Tuller T. Prokaryotic rRNA-mRNA interactions are involved in all translation steps and shape bacterial transcripts. RNA Biol 2021; 18:684-698. [PMID: 34586043 DOI: 10.1080/15476286.2021.1978767] [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] [Indexed: 10/20/2022] Open
Abstract
The well-established Shine-Dalgarno model suggests that translation initiation in bacteria is regulated via base-pairing between ribosomal RNA (rRNA) and mRNA. We used novel computational analyses and modelling of 823 bacterial genomes coupled with experiments to demonstrate that rRNA-mRNA interactions are diverse and regulate all translation steps from pre-initiation to termination. Previous research has reported the significant influence of rRNA-mRNA interactions, mainly in the initiation phase of translation. The results reported in this paper suggest that, in addition to the rRNA-mRNA interactions near the start codon that trigger initiation in bacteria, rRNA-mRNA interactions affect all sub-stages of the translation process (pre-initiation, initiation, elongation, termination). As these interactions dictate translation efficiency, they serve as an evolutionary driving force for shaping transcripts in bacteria while considering trade-offs between the effects of different interactions across different transcript regions on translation efficacy and efficiency. We observed selection for strong interactions in regions where such interactions are likely to enhance initiation, regulate early elongation, and ensure translation termination fidelity. We discovered selection against strong interactions and for intermediate interactions in coding regions and presented evidence that these patterns maximize elongation efficiency while also enhancing initiation. These finding are relevant to all biomedical disciplines due to the centrality of the translation process and the effect of rRNA-mRNA interactions on transcript evolution.
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Affiliation(s)
| | | | - Dana Yacobi
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Larissa Fine
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Boaz Apt
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Alon Diament
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Tamir Tuller
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel.,The Sagol School of Neuroscience, Tel-Aviv University, Tel Aviv, Israel
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7
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Callens M, Pradier L, Finnegan M, Rose C, Bedhomme S. Read between the lines: Diversity of non-translational selection pressures on local codon usage. Genome Biol Evol 2021; 13:6263832. [PMID: 33944930 PMCID: PMC8410138 DOI: 10.1093/gbe/evab097] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/28/2021] [Indexed: 12/14/2022] Open
Abstract
Protein coding genes can contain specific motifs within their nucleotide sequence that function as a signal for various biological pathways. The presence of such sequence motifs within a gene can have beneficial or detrimental effects on the phenotype and fitness of an organism, and this can lead to the enrichment or avoidance of this sequence motif. The degeneracy of the genetic code allows for the existence of alternative synonymous sequences that exclude or include these motifs, while keeping the encoded amino acid sequence intact. This implies that locally, there can be a selective pressure for preferentially using a codon over its synonymous alternative in order to avoid or enrich a specific sequence motif. This selective pressure could -in addition to mutation, drift and selection for translation efficiency and accuracy- contribute to shape the codon usage bias. In this review, we discuss patterns of avoidance of (or enrichment for) the various biological signals contained in specific nucleotide sequence motifs: transcription and translation initiation and termination signals, mRNA maturation signals, and antiviral immune system targets. Experimental data on the phenotypic or fitness effects of synonymous mutations in these sequence motifs confirm that they can be targets of local selection pressures on codon usage. We also formulate the hypothesis that transposable elements could have a similar impact on codon usage through their preferred integration sequences. Overall, selection on codon usage appears to be a combination of a global selection pressure imposed by the translation machinery, and a patchwork of local selection pressures related to biological signals contained in specific sequence motifs.
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Affiliation(s)
- Martijn Callens
- Centre d'Ecologie Fonctionnelle et Evolutive, CNRS, Université de Montpellier, Université Paul Valéry Montpellier 3, Ecole Pratique des Hautes Etudes, Institut de Recherche pour le Développement, 34000 Montpellier, France
| | - Léa Pradier
- Centre d'Ecologie Fonctionnelle et Evolutive, CNRS, Université de Montpellier, Université Paul Valéry Montpellier 3, Ecole Pratique des Hautes Etudes, Institut de Recherche pour le Développement, 34000 Montpellier, France
| | - Michael Finnegan
- Centre d'Ecologie Fonctionnelle et Evolutive, CNRS, Université de Montpellier, Université Paul Valéry Montpellier 3, Ecole Pratique des Hautes Etudes, Institut de Recherche pour le Développement, 34000 Montpellier, France
| | - Caroline Rose
- Centre d'Ecologie Fonctionnelle et Evolutive, CNRS, Université de Montpellier, Université Paul Valéry Montpellier 3, Ecole Pratique des Hautes Etudes, Institut de Recherche pour le Développement, 34000 Montpellier, France
| | - Stéphanie Bedhomme
- Centre d'Ecologie Fonctionnelle et Evolutive, CNRS, Université de Montpellier, Université Paul Valéry Montpellier 3, Ecole Pratique des Hautes Etudes, Institut de Recherche pour le Développement, 34000 Montpellier, France
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8
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Nieuwkoop T, Finger-Bou M, van der Oost J, Claassens NJ. The Ongoing Quest to Crack the Genetic Code for Protein Production. Mol Cell 2020; 80:193-209. [PMID: 33010203 DOI: 10.1016/j.molcel.2020.09.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 08/10/2020] [Accepted: 09/10/2020] [Indexed: 01/05/2023]
Abstract
Understanding the genetic design principles that determine protein production remains a major challenge. Although the key principles of gene expression were discovered 50 years ago, additional factors are still being uncovered. Both protein-coding and non-coding sequences harbor elements that collectively influence the efficiency of protein production by modulating transcription, mRNA decay, and translation. The influences of many contributing elements are intertwined, which complicates a full understanding of the individual factors. In natural genes, a functional balance between these factors has been obtained in the course of evolution, whereas for genetic-engineering projects, our incomplete understanding still limits optimal design of synthetic genes. However, notable advances have recently been made, supported by high-throughput analysis of synthetic gene libraries as well as by state-of-the-art biomolecular techniques. We discuss here how these advances further strengthen understanding of the gene expression process and how they can be harnessed to optimize protein production.
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Affiliation(s)
- Thijs Nieuwkoop
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Max Finger-Bou
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - John van der Oost
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Nico J Claassens
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, the Netherlands.
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9
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Saito K, Green R, Buskirk AR. Translational initiation in E. coli occurs at the correct sites genome-wide in the absence of mRNA-rRNA base-pairing. eLife 2020; 9:55002. [PMID: 32065583 PMCID: PMC7043885 DOI: 10.7554/elife.55002] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 02/14/2020] [Indexed: 12/21/2022] Open
Abstract
Shine-Dalgarno (SD) motifs are thought to play an important role in translational initiation in bacteria. Paradoxically, ribosome profiling studies in E. coli show no correlation between the strength of an mRNA’s SD motif and how efficiently it is translated. Performing profiling on ribosomes with altered anti-Shine-Dalgarno sequences, we reveal a genome-wide correlation between SD strength and ribosome occupancy that was previously masked by other contributing factors. Using the antibiotic retapamulin to trap initiation complexes at start codons, we find that the mutant ribosomes select start sites correctly, arguing that start sites are hard-wired for initiation through the action of other mRNA features. We show that A-rich sequences upstream of start codons promote initiation. Taken together, our genome-wide study reveals that SD motifs are not necessary for ribosomes to determine where initiation occurs, though they do affect how efficiently initiation occurs.
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Affiliation(s)
- Kazuki Saito
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Rachel Green
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, United States.,Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Allen R Buskirk
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, United States
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10
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Vincent RM, Wright BW, Jaschke PR. Measuring Amber Initiator tRNA Orthogonality in a Genomically Recoded Organism. ACS Synth Biol 2019; 8:675-685. [PMID: 30856316 DOI: 10.1021/acssynbio.9b00021] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Using engineered initiator tRNA for precise control of protein translation within cells has great promise within future orthogonal translation systems to decouple housekeeping protein metabolism from that of engineered genetic systems. Previously, E. coli strain C321.ΔA. exp lacking all UAG stop codons was created, freeing this "amber" stop codon for other purposes. An engineered "amber initiator" tRNACUAfMet that activates translation at UAG codons is available, but little is known about this tRNA's orthogonality. Here, we combine for the first time the amber initiator tRNACUAfMet in C321.ΔA. exp and measure its cellular effects. We found that the tRNACUAfMet expression resulted in a nearly 200-fold increase in fluorescent reporter expression with a unimodal population distribution and no apparent cellular fitness defects. Proteomic analysis revealed upregulated ribosome-associated, tRNA degradation, and amino acid biosynthetic proteins, with no evidence for off-target translation initiation. In contrast to previous work, we show that UAG-initiated proteins carry N-terminal methionine, but have no evidence for glutamine. Together, our results identify beneficial features of using the amber initiator tRNACUAfMet to control gene expression while also revealing fundamental challenges to using engineered initiator tRNAs as the basis for orthogonal translation initiation systems.
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Affiliation(s)
- Russel M. Vincent
- Department of Molecular Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Bradley W. Wright
- Department of Molecular Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Paul R. Jaschke
- Department of Molecular Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
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