1
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Delgadillo-Guevara M, Halte M, Erhardt M, Popp PF. Fluorescent tools for the standardized work in Gram-negative bacteria. J Biol Eng 2024; 18:25. [PMID: 38589953 PMCID: PMC11003136 DOI: 10.1186/s13036-024-00420-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Accepted: 03/18/2024] [Indexed: 04/10/2024] Open
Abstract
Standardized and thoroughly characterized genetic tools are a prerequisite for studying cellular processes to ensure the reusability and consistency of experimental results. The discovery of fluorescent proteins (FPs) represents a milestone in the development of genetic reporters for monitoring transcription or protein localization in vivo. FPs have revolutionized our understanding of cellular dynamics by enabling the real-time visualization and tracking of biological processes. Despite these advancements, challenges remain in the appropriate use of FPs, specifically regarding their proper application, protein turnover dynamics, and the undesired disruption of cellular functions. Here, we systematically compared a comprehensive set of 15 FPs and assessed their performance in vivo by focusing on key parameters, such as signal over background ratios and protein stability rates, using the Gram-negative model organism Salmonella enterica as a representative host. We evaluated four protein degradation tags in both plasmid- and genome-based systems and our findings highlight the necessity of introducing degradation tags to analyze time-sensitive cellular processes. We demonstrate that the gain of dynamics mediated by the addition of degradation tags impacts the cell-to-cell heterogeneity of plasmid-based but not genome-based reporters. Finally, we probe the applicability of FPs for protein localization studies in living cells using standard and super-resolution fluorescence microscopy. In summary, our study underscores the importance of careful FP selection and paves the way for the development of improved genetic reporters to enhance the reproducibility and reliability of fluorescence-based research in Gram-negative bacteria and beyond.
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Affiliation(s)
- Mario Delgadillo-Guevara
- Institute of Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, 10115, Germany
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, VIC, Australia
| | - Manuel Halte
- Institute of Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, 10115, Germany
| | - Marc Erhardt
- Institute of Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, 10115, Germany
- Max Planck Unit for the Science of Pathogens, Berlin, 10117, Germany
| | - Philipp F Popp
- Institute of Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Berlin, 10115, Germany.
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2
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Reed P, Sorg M, Alwardt D, Serra L, Veiga H, Schäper S, Pinho MG. A CRISPRi-based genetic resource to study essential Staphylococcus aureus genes. mBio 2024; 15:e0277323. [PMID: 38054745 PMCID: PMC10870820 DOI: 10.1128/mbio.02773-23] [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: 10/13/2023] [Accepted: 10/19/2023] [Indexed: 12/07/2023] Open
Abstract
IMPORTANCE Staphylococcus aureus is an important clinical pathogen that causes a high number of antibiotic-resistant infections. The study of S. aureus biology, and particularly of the function of essential proteins, is of particular importance to develop new approaches to combat this pathogen. We have optimized a clustered regularly interspaced short palindromic repeat interference (CRISPRi) system that allows efficient targeting of essential S. aureus genes. Furthermore, we have used that system to construct a library comprising 261 strains, which allows the depletion of essential proteins encoded by 200 genes/operons. This library, which we have named Lisbon CRISPRi Mutant Library, should facilitate the study of S. aureus pathogenesis and biology.
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Affiliation(s)
- Patricia Reed
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Moritz Sorg
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Dominik Alwardt
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Lúcia Serra
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Helena Veiga
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Simon Schäper
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Mariana G. Pinho
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
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3
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Fusco F, Pires MC, Lopes APY, Alves VDS, Gonçalves VM. Influence of the mRNA initial region on protein production: a case study using recombinant detoxified pneumolysin as a model. Front Bioeng Biotechnol 2024; 11:1304965. [PMID: 38260740 PMCID: PMC10800503 DOI: 10.3389/fbioe.2023.1304965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Accepted: 12/12/2023] [Indexed: 01/24/2024] Open
Abstract
Recombinant proteins are of great importance in modern society, mostly as biopharmaceutical products. However, challenging and complex processes with low production yield are major drawbacks. Normally, the optimization to overcome these obstacles is focused on bioreactor and purification processes, and the biomolecular aspects are neglected, seen as less important. In this work, we present how the 5' mRNA secondary structure region can be relevant for translation and, therefore, protein production. For this, Escherichia coli BL21(DE3) clones, producing recombinant detoxified pneumolysin (PdT) with and without the N-terminal His-tag, were cultivated in 10-L bioreactors. Another version of the pdt gene (version 2) with synonymous changes in the 5'-end nucleotide sequence was also obtained. Protein production, plasmid stability, carbon sources, and acetic acid were quantified during the cultures. Furthermore, in silico mRNA analyses were performed using TIsigner and RNAfold. The results showed that the His-tag presence at the N-terminus generated a minimum 1.5-fold increase in target protein synthesis, which was explained by the in silico mRNA analyses that returned an mRNA secondary structure easier to translate and, therefore, higher protein production than without the His-tag. The pdt gene version 2 showed lower 5' mRNA opening energy than version 1, allowing higher PdT production even without a tag. This work reveals that simple mRNA analyses during heterologous gene design and production steps can help reach high-recombinant protein titers in a shorter time than using only traditional bioprocess optimization strategies.
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Affiliation(s)
- Filipe Fusco
- Laboratory of Vaccine Development, Butantan Institute, Sao Paulo, Brazil
- Interunits Graduate Program in Biotechnology, University of Sao Paulo, Sao Paulo, Brazil
| | - Manuella Cazelato Pires
- Laboratory of Vaccine Development, Butantan Institute, Sao Paulo, Brazil
- Interunits Graduate Program in Biotechnology, University of Sao Paulo, Sao Paulo, Brazil
| | | | - Vítor dos Santos Alves
- Laboratory of Vaccine Development, Butantan Institute, Sao Paulo, Brazil
- Interunits Graduate Program in Biotechnology, University of Sao Paulo, Sao Paulo, Brazil
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4
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Rao X, Li D, Su Z, Nomura CT, Chen S, Wang Q. A smart RBS library and its prediction model for robust and accurate fine-tuning of gene expression in Bacillus species. Metab Eng 2024; 81:1-9. [PMID: 37951459 DOI: 10.1016/j.ymben.2023.11.002] [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] [Received: 08/15/2023] [Revised: 10/17/2023] [Accepted: 11/05/2023] [Indexed: 11/14/2023]
Abstract
Bacillus species, such as Bacillus subtilis and Bacillus licheniformis, are important industrial bacteria. However, there is a lack of standardized and predictable genetic tools for convenient and reproducible assembly of genetic modules in Bacillus species to realize their full potential. In this study, we constructed a Ribosome Binding Site (RBS) library in B. licheniformis, which provides incremental regulation of expression levels over a 104-fold range. Additionally, we developed a model to quantify the resulting translation rates. We successfully demonstrated the robust expression of various target genes using the RBS library and showed that the model accurately predicts the translation rates of arbitrary coding genes. Importantly, we also extended the use of the RBS library and prediction model to B. subtilis, B. thuringiensis, and B. amyloliquefacie. The versatility of the RBS library and its prediction model enables quantification of biological behavior, facilitating reliable forward engineering of gene expression.
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Affiliation(s)
- Xiaolan Rao
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, Hubei University, Wuhan 430062, PR China
| | - Dian Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, Hubei University, Wuhan 430062, PR China
| | - Zhaowei Su
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, Hubei University, Wuhan 430062, PR China
| | | | - Shouwen Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, Hubei University, Wuhan 430062, PR China.
| | - Qin Wang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, Hubei University, Wuhan 430062, PR China.
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5
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Jun JS, Jeong HE, Hong KW. Exploring and Engineering Novel Strong Promoters for High-Level Protein Expression in Bacillus subtilis DB104 through Transcriptome Analysis. Microorganisms 2023; 11:2929. [PMID: 38138072 PMCID: PMC10745405 DOI: 10.3390/microorganisms11122929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 12/01/2023] [Accepted: 12/05/2023] [Indexed: 12/24/2023] Open
Abstract
Bacillus subtilis is widely employed for recombinant protein expression. B. subtilis DB104 offers a distinct advantage as a protein expression host because it is an extracellular protease-deficient derivative of B. subtilis 168. We have conducted a time-course transcriptome analysis of B. subtilis DB104 in a prior study. In the present study, we identified 10 genes that exhibited strong expression at each time point or all, based on transcriptome data. Subsequently, we assessed the strength of 12 promoters that transcribe these genes using enhanced green fluorescent protein (eGFP) as a reporter. Among these promoters, Psdp and PskfA had the highest expression levels. At 24 h, these two promoters exhibited 34.5- and 38.8-fold higher strength, respectively, than the strength of P43, the control promoter. Consequently, these two promoters were selected for further development. We enhanced these promoters by optimizing spacer length, promoter sequence, Shine-Dalgarno sequence, regulator binding sites, and terminator sequences. As a result, we successfully engineered the most potent protein expression cassette, Psdp-4, which exhibited a 3.84-fold increase in strength compared to the original Psdp promoter. Furthermore, we constructed an expression cassette for a human epidermal growth factor (hEGF) using Psdp-4 to evaluate its general application. The expression level of His tagged hEGF, quantified using ImageJ analysis and applied to SDS-PAGE, reached the highest yield of 103.9 μg/mL under the control of Psdp-4 at 24 h. The expressed hEGF protein was purified, and its bioactivity was confirmed through a cell proliferation assay using HT-29 cells. Our work demonstrates the construction of a highly efficient expression system for B. subtilis DB104 based on transcriptome data and promoter engineering. This system enables rapid, inducer-free protein expression within 24 h. It can be used as a valuable tool for various industrial applications.
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Affiliation(s)
| | | | - Kwang-Won Hong
- Department of Food Science and Biotechnology, College of Life Science and Biotechnology, Dongguk University, Goyang-si 10326, Republic of Korea; (J.-S.J.); (H.-E.J.)
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6
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Hegelmeyer NK, Parkin LA, Previti ML, Andrade J, Utama R, Sejour RJ, Gardin J, Muller S, Ketchum S, Yurovsky A, Futcher B, Goodwin S, Ueberheide B, Seeliger JC. Gene recoding by synonymous mutations creates promiscuous intragenic transcription initiation in mycobacteria. mBio 2023; 14:e0084123. [PMID: 37787543 PMCID: PMC10653884 DOI: 10.1128/mbio.00841-23] [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: 04/05/2023] [Accepted: 08/16/2023] [Indexed: 10/04/2023] Open
Abstract
IMPORTANCE Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis, one of the deadliest infectious diseases worldwide. Previous studies have established that synonymous recoding to introduce rare codon pairings can attenuate viral pathogens. We hypothesized that non-optimal codon pairing could be an effective strategy for attenuating gene expression to create a live vaccine for Mtb. We instead discovered that these synonymous changes enabled the transcription of functional mRNA that initiated in the middle of the open reading frame and from which many smaller protein products were expressed. To our knowledge, this is one of the first reports that synonymous recoding of a gene in any organism can create or induce intragenic transcription start sites.
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Affiliation(s)
- Nuri K. Hegelmeyer
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Lia A. Parkin
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Mary L. Previti
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Joshua Andrade
- Proteomics Laboratory, New York University Grossman School of Medicine, New York, New York, USA
| | - Raditya Utama
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Richard J. Sejour
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Justin Gardin
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Stephanie Muller
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Steven Ketchum
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Alisa Yurovsky
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Bruce Futcher
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Sara Goodwin
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Beatrix Ueberheide
- Proteomics Laboratory, New York University Grossman School of Medicine, New York, New York, USA
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, New York, USA
| | - Jessica C. Seeliger
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
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7
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Höllerer S, Jeschek M. Ultradeep characterisation of translational sequence determinants refutes rare-codon hypothesis and unveils quadruplet base pairing of initiator tRNA and transcript. Nucleic Acids Res 2023; 51:2377-2396. [PMID: 36727459 PMCID: PMC10018350 DOI: 10.1093/nar/gkad040] [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: 06/17/2022] [Revised: 12/05/2022] [Accepted: 01/13/2023] [Indexed: 02/03/2023] Open
Abstract
Translation is a key determinant of gene expression and an important biotechnological engineering target. In bacteria, 5'-untranslated region (5'-UTR) and coding sequence (CDS) are well-known mRNA parts controlling translation and thus cellular protein levels. However, the complex interaction of 5'-UTR and CDS has so far only been studied for few sequences leading to non-generalisable and partly contradictory conclusions. Herein, we systematically assess the dynamic translation from over 1.2 million 5'-UTR-CDS pairs in Escherichia coli to investigate their collective effect using a new method for ultradeep sequence-function mapping. This allows us to disentangle and precisely quantify effects of various sequence determinants of translation. We find that 5'-UTR and CDS individually account for 53% and 20% of variance in translation, respectively, and show conclusively that, contrary to a common hypothesis, tRNA abundance does not explain expression changes between CDSs with different synonymous codons. Moreover, the obtained large-scale data provide clear experimental evidence for a base-pairing interaction between initiator tRNA and mRNA beyond the anticodon-codon interaction, an effect that is often masked for individual sequences and therefore inaccessible to low-throughput approaches. Our study highlights the indispensability of ultradeep sequence-function mapping to accurately determine the contribution of parts and phenomena involved in gene regulation.
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Affiliation(s)
- Simon Höllerer
- Department of Biosystems Science and Engineering, Swiss Federal Institute of Technology – ETH Zurich, Basel CH-4058, Switzerland
| | - Markus Jeschek
- Department of Biosystems Science and Engineering, Swiss Federal Institute of Technology – ETH Zurich, Basel CH-4058, Switzerland
- Institute of Microbiology, Synthetic Microbiology Group, University of Regensburg, Regensburg D-93053, Germany
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8
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Hegelmeyer NK, Previti ML, Andrade J, Utama R, Sejour RJ, Gardin J, Muller S, Ketchum S, Yurovsky A, Futcher B, Goodwin S, Ueberheide B, Seeliger JC. Gene recoding by synonymous mutations creates promiscuous intragenic transcription initiation in mycobacteria. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.17.532606. [PMID: 36993691 PMCID: PMC10055193 DOI: 10.1101/2023.03.17.532606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Each genome encodes some codons more frequently than their synonyms (codon usage bias), but codons are also arranged more frequently into specific pairs (codon pair bias). Recoding viral genomes and yeast or bacterial genes with non-optimal codon pairs has been shown to decrease gene expression. Gene expression is thus importantly regulated not only by the use of particular codons but by their proper juxtaposition. We therefore hypothesized that non-optimal codon pairing could likewise attenuate Mtb genes. We explored the role of codon pair bias by recoding Mtb genes ( rpoB, mmpL3, ndh ) and assessing their expression in the closely related and tractable model organism M. smegmatis . To our surprise, recoding caused the expression of multiple smaller protein isoforms from all three genes. We confirmed that these smaller proteins were not due to protein degradation, but instead issued from new transcription initiation sites positioned within the open reading frame. New transcripts gave rise to intragenic translation initiation sites, which in turn led to the expression of smaller proteins. We next identified the nucleotide changes associated with these new sites of transcription and translation. Our results demonstrated that apparently benign, synonymous changes can drastically alter gene expression in mycobacteria. More generally, our work expands our understanding of the codon-level parameters that control translation and transcription initiation. IMPORTANCE Mycobacterium tuberculosis ( Mtb ) is the causative agent of tuberculosis, one of the deadliest infectious diseases worldwide. Previous studies have established that synonymous recoding to introduce rare codon pairings can attenuate viral pathogens. We hypothesized that non-optimal codon pairing could be an effective strategy for attenuating gene expression to create a live vaccine for Mtb . We instead discovered that these synonymous changes enabled the transcription of functional mRNA that initiated in the middle of the open reading frame and from which many smaller protein products were expressed. To our knowledge, this is the first report that synonymous recoding of a gene in any organism can create or induce intragenic transcription start sites.
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Affiliation(s)
- Nuri K. Hegelmeyer
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Mary L. Previti
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Joshua Andrade
- Proteomics Laboratory, New York University Grossman School of Medicine, New York, New York, USA
| | - Raditya Utama
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Richard J. Sejour
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Justin Gardin
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Stephanie Muller
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Steven Ketchum
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Alisa Yurovsky
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Bruce Futcher
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Sara Goodwin
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Beatrix Ueberheide
- Proteomics Laboratory, New York University Grossman School of Medicine, New York, New York, USA
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, New York, USA
| | - Jessica C. Seeliger
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
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9
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Xue D, Shang Z, Older EA, Zhong Z, Pulliam C, Peter K, Nagarkatti M, Nagarkatti P, Li YX, Li J. Refactoring and Heterologous Expression of Class III Lanthipeptide Biosynthetic Gene Clusters Lead to the Discovery of N, N-Dimethylated Lantibiotics from Firmicutes. ACS Chem Biol 2023; 18:508-517. [PMID: 36926816 PMCID: PMC10069475 DOI: 10.1021/acschembio.2c00849] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
Class III lanthipeptides are an emerging subclass of lanthipeptides, representing an underexplored trove of new natural products with potentially broad chemical diversity and important biological activity. Bioinformatic analysis of class III lanthipeptide biosynthetic gene cluster (BGC) distribution has revealed their high abundance in the phylum Firmicutes. Many of these clusters also feature methyltransferase (MT) genes, which likely encode uncommon class III lanthipeptides. However, two hurdles, silent BGCs and low-yielding pathways, have hindered the discovery of class III lanthipeptides from Firmicutes. Here, we report the design and construction of a biosynthetic pathway refactoring and heterologous overexpression strategy which seeks to overcome these hurdles, simultaneously activating and increasing the production of these Firmicutes class III lanthipeptides. Applying our strategy to MT-containing BGCs, we report the discovery of new class III lanthipeptides from Firmicutes bearing rare N,N-dimethylations. We reveal the importance of the first two amino acids in the N-terminus of the core peptide in controlling the MT dimethylation activity. Leveraging this feature, we engineer class III lanthipeptides to enable N,N-dimethylation, resulting in significantly increased antibacterial activity. Furthermore, the refactoring and heterologous overexpression strategy showcased in this study is potentially applicable to other ribosomally synthesized and post-translationally modified peptide BGCs from Firmicutes, unlocking the genetic potential of Firmicutes for producing peptide natural products.
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Affiliation(s)
- Dan Xue
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Zhuo Shang
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Ethan A Older
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Zheng Zhong
- Department of Chemistry and the Swire Institute of Marine Science, The University of Hong Kong, Hong Kong 999077, China.,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 519000, China
| | - Conor Pulliam
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Kyle Peter
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Mitzi Nagarkatti
- Department of Pathology, Microbiology and Immunology, School of Medicine, University of South Carolina, Columbia, South Carolina 29209, United States
| | - Prakash Nagarkatti
- Department of Pathology, Microbiology and Immunology, School of Medicine, University of South Carolina, Columbia, South Carolina 29209, United States
| | - Yong-Xin Li
- Department of Chemistry and the Swire Institute of Marine Science, The University of Hong Kong, Hong Kong 999077, China.,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 519000, China
| | - Jie Li
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
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10
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Zhang M, Song J, Xiao J, Jin J, Nomura CT, Chen S, Wang Q. Engineered multiple translation initiation sites: a novel tool to enhance protein production in Bacillus licheniformis and other industrially relevant bacteria. Nucleic Acids Res 2022; 50:11979-11990. [PMID: 36382403 PMCID: PMC9723656 DOI: 10.1093/nar/gkac1039] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 10/18/2022] [Accepted: 10/31/2022] [Indexed: 11/17/2022] Open
Abstract
Gram-positive bacteria are a nascent platform for synthetic biology and metabolic engineering that can provide new opportunities for the production of biomolecules. However, the lack of standardized methods and genetic parts is a major obstacle towards attaining the acceptance and widespread use of Gram-positive bacterial chassis for industrial bioproduction. In this study, we have engineered a novel mRNA leader sequence containing more than one ribosomal binding site (RBS) which could initiate translation from multiple sites, vastly enhancing the translation efficiency of the Gram-positive industrial strain Bacillus licheniformis. This is the first report elucidating the impact of more than one RBS to initiate translation and enhance protein output in B. licheniformis. We also explored the application of more than one RBS for both intracellular and extracellular protein production in B. licheniformis to demonstrate its efficiency, consistency and potential for biotechnological applications. Moreover, we applied these concepts for use in other industrially relevant Gram-positive bacteria, such as Bacillus subtilis and Corynebacterium glutamicum. In all, a highly efficient and robust broad-host expression element has been designed to strengthen and fine-tune the protein outputs for the use of bioproduction in microbial cell factories.
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Affiliation(s)
- Manyu Zhang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Science, Hubei University, Wuhan 430062, China
| | | | - Jun Xiao
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Science, Hubei University, Wuhan 430062, China
| | - Jingjie Jin
- Key Laboratory of Functional Protein Research of Guangdong Higher Education Institutes, Institute of Life and Health Engineering, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Christopher T Nomura
- Department of Biological Sciences, University of Idaho, 875 Perimeter Drive, Moscow, ID 83844, USA
| | - Shouwen Chen
- Correspondence may also be addressed to Shouwen Chen.
| | - Qin Wang
- To whom correspondence should be addressed. Tel: +86 18507140137;
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11
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De Wannemaeker L, Bervoets I, De Mey M. Unlocking the bacterial domain for industrial biotechnology applications using universal parts and tools. Biotechnol Adv 2022; 60:108028. [PMID: 36031082 DOI: 10.1016/j.biotechadv.2022.108028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 07/29/2022] [Accepted: 08/16/2022] [Indexed: 11/02/2022]
Abstract
Synthetic biology can play a major role in the development of sustainable industrial biotechnology processes. However, the development of economically viable production processes is currently hampered by the limited availability of host organisms that can be engineered for a specific production process. To date, standard hosts such as Escherichia coli and Saccharomyces cerevisiae are often used as starting points for process development since parts and tools allowing their engineering are readily available. However, their suboptimal metabolic background or impaired performance at industrial scale for a desired production process, can result in increased costs associated with process development and/or disappointing production titres. Building a universal and portable gene expression system allowing genetic engineering of hosts across the bacterial domain would unlock the bacterial domain for industrial biotechnology applications in a highly standardized manner and doing so, render industrial biotechnology processes more competitive compared to the current polluting chemical processes. This review gives an overview of a selection of bacterial hosts highly interesting for industrial biotechnology based on both their metabolic and process optimization properties. Moreover, the requirements and progress made so far to enable universal, standardized, and portable gene expression across the bacterial domain is discussed.
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Affiliation(s)
- Lien De Wannemaeker
- Centre for Synthetic Biology (CSB), Ghent University, Coupure links 653, 9000 Ghent, Belgium
| | - Indra Bervoets
- Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Marjan De Mey
- Centre for Synthetic Biology (CSB), Ghent University, Coupure links 653, 9000 Ghent, Belgium.
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12
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Nøhr-Meldgaard K, Struve C, Ingmer H, Agersø Y. Intrinsic tet(L) sub-class in Bacillus velezensis and Bacillus amyloliquefaciens is associated with a reduced susceptibility toward tetracycline. Front Microbiol 2022; 13:966016. [PMID: 35992677 PMCID: PMC9387203 DOI: 10.3389/fmicb.2022.966016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 07/19/2022] [Indexed: 11/13/2022] Open
Abstract
Annotations of non-pathogenic bacterial genomes commonly reveal putative antibiotic resistance genes and the potential risks associated with such genes is challenging to assess. We have examined a putative tetracycline tet(L) gene (conferring low level tetracycline resistance), present in the majority of all publicly available genomes of the industrially important operational group Bacillus amyloliquefaciens including the species B. amyloliquefaciens, Bacillus siamensis and Bacillus velezensis. The aim was to examine the risk of transfer of the putative tet(L) in operational group B. amyloliquefaciens through phylogenetic and genomic position analysis. These analyses furthermore included tet(L) genes encoded by transferable plasmids and other Gram-positive and -negative bacteria, including Bacillus subtilis. Through phylogenetic analysis, we could group chromosomally and plasmid-encoded tet(L) genes into four phylogenetic clades. The chromosomally encoded putative tet(L) from operational group B. amyloliquefaciens formed a separate phylogenetic clade; was positioned in the same genomic region in the three species; was not flanked by mobile genetic elements and was not found in any other bacterial species suggesting that the gene has been present in a common ancestor before species differentiation and is intrinsic. Therefore the gene is not considered a safety concern, and the risk of transfer to and expression of resistance in other non-related species is considered negligible. We suggest a subgrouping of the tet(L) class into four groups (tet(L)1.1, tet(L)1.2 and tet(L)2.1, tet(L)2.2), corresponding with the phylogenetic grouping and tet(L) from operational group B. amyloliquefaciens referred to as tet(L)2.2. Phylogenetic analysis is a useful tool to correctly differentiate between intrinsic and acquired antibiotic resistance genes.
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Affiliation(s)
- Katrine Nøhr-Meldgaard
- Chr. Hansen A/S, Hørsholm, Denmark
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Hanne Ingmer
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Yvonne Agersø
- Chr. Hansen A/S, Hørsholm, Denmark
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
- *Correspondence: Yvonne Agersø,
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13
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Duan Y, Zhang X, Zhai W, Zhang J, Zhang X, Xu G, Li H, Deng Z, Shi J, Xu Z. Deciphering the Rules of Ribosome Binding Site Differentiation in Context Dependence. ACS Synth Biol 2022; 11:2726-2740. [PMID: 35877551 DOI: 10.1021/acssynbio.2c00139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ribosome binding site (RBS) is a crucial element regulating translation. However, the activity of RBS is poorly predictable, because it is strongly affected by the local possible secondary structure, that is, context dependence. By the Flowseq technique, over 20 000 RBS variants were sorted and sequenced, and the translation of multiple genes under the same RBS was quantitatively characterized to evaluate the context dependence of each RBS variant in E. coli. Two regions, (-7 to -2) and (-17 to -12), of RBS were predicted with a higher possibility to pair with each other to slow down the translation initiation. Associations between phenotypes and the intrinsic factors suspected to affect translation efficiency and context dependence of the RBS, including nucleotide bias at each position, free energy, and conservation, were disentangled. The results showed that translation efficiency was influenced more significantly by conservation of the SD region (-16 to -8), while an AC-rich spacer region (-7 to -1) was associated with low context dependence. We confirmed these characteristics using a series of synthesized RBSs. The average correlation between multiple reporters was significantly higher for RBSs with an AC-rich spacer (0.714) compared with a GU-rich spacer (0.286). Overall, we proposed general design criteria to improve programmability and minimize context dependence of RBS. The characteristics unraveled here can be adapted to other bacteria for fine-tuning target-gene expression.
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Affiliation(s)
- Yanting Duan
- Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China
| | - Xiaojuan Zhang
- Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China
| | - Weiji Zhai
- Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China
| | - Jinpeng Zhang
- Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China
| | - Xiaomei Zhang
- School of Life Science and Health Engineering, Jiangnan University, Wuxi 214122, China.,Jiangsu Engineering Research Center for Bioactive Products Processing Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Guoqiang Xu
- Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China
| | - Hui Li
- School of Artificial Intelligence and Computer Science, Jiangnan University, Wuxi 214122, China
| | - Zhaohong Deng
- School of Artificial Intelligence and Computer Science, Jiangnan University, Wuxi 214122, China
| | - Jinsong Shi
- School of Life Science and Health Engineering, Jiangnan University, Wuxi 214122, China.,Jiangsu Engineering Research Center for Bioactive Products Processing Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Zhenghong Xu
- Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China
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14
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Discovery of Unannotated Small Open Reading Frames in Streptococcus pneumoniae D39 Involved in Quorum Sensing and Virulence Using Ribosome Profiling. mBio 2022; 13:e0124722. [PMID: 35852327 PMCID: PMC9426450 DOI: 10.1128/mbio.01247-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococcus pneumoniae, an opportunistic human pathogen, is the leading cause of community-acquired pneumonia and an agent of otitis media, septicemia, and meningitis. Although genomic and transcriptomic studies of S. pneumoniae have provided detailed perspectives on gene content and expression programs, they have lacked information pertaining to the translational landscape, particularly at a resolution that identifies commonly overlooked small open reading frames (sORFs), whose importance is increasingly realized in metabolism, regulation, and virulence. To identify protein-coding sORFs in S. pneumoniae, antibiotic-enhanced ribosome profiling was conducted. Using translation inhibitors, 114 novel sORFs were detected, and the expression of a subset of them was experimentally validated. Two loci associated with virulence and quorum sensing were examined in deeper detail. One such sORF, rio3, overlaps with the noncoding RNA srf-02 that was previously implicated in pathogenesis. Targeted mutagenesis parsing rio3 from srf-02 revealed that rio3 is responsible for the fitness defect seen in a murine nasopharyngeal colonization model. Additionally, two novel sORFs located adjacent to the quorum sensing receptor rgg1518 were found to impact regulatory activity. Our findings emphasize the importance of sORFs present in the genomes of pathogenic bacteria and underscore the utility of ribosome profiling for identifying the bacterial translatome.
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15
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Cell-free production of personalized therapeutic phages targeting multidrug-resistant bacteria. Cell Chem Biol 2022; 29:1434-1445.e7. [PMID: 35820417 DOI: 10.1016/j.chembiol.2022.06.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 03/11/2022] [Accepted: 06/16/2022] [Indexed: 12/26/2022]
Abstract
Bacteriophages are potent therapeutics against biohazardous bacteria, which rapidly develop multidrug resistance. However, routine administration of phage therapy is hampered by a lack of rapid production, safe bioengineering, and detailed characterization of phages. Thus, we demonstrate a comprehensive cell-free platform for personalized production, transient engineering, and proteomic characterization of a broad spectrum of phages. Using mass spectrometry, we validated hypothetical and non-structural proteins and could also monitor the protein expression during phage assembly. Notably, a few microliters of a one-pot reaction produced effective doses of phages against enteroaggregative Escherichia coli (EAEC), Yersinia pestis, and Klebsiella pneumoniae. By co-expressing suitable host factors, we could extend the range of cell-free production to phages targeting gram-positive bacteria. We further introduce a non-genomic phage engineering method, which adds functionalities for only one replication cycle. In summary, we expect this cell-free methodology to foster reverse and forward phage engineering and customized production of clinical-grade bacteriophages.
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16
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Niu J, Yan R, Shen J, Zhu X, Meng F, Lu Z, Lu F. Cis-Element Engineering Promotes the Expression of Bacillus subtilis Type I L-Asparaginase and Its Application in Food. Int J Mol Sci 2022; 23:ijms23126588. [PMID: 35743032 PMCID: PMC9224341 DOI: 10.3390/ijms23126588] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/08/2022] [Accepted: 06/09/2022] [Indexed: 02/06/2023] Open
Abstract
Type I L-asparaginase from Bacillus licheniformis Z-1 (BlAase) was efficiently produced and secreted in Bacillus subtilis RIK 1285, but its low yield made it unsuitable for industrial use. Thus, a combined method was used in this study to boost BlAase synthesis in B. subtilis. First, fifteen single strong promoters were chosen to replace the original promoter P43, with PyvyD achieving the greatest BlAase activity (436.28 U/mL). Second, dual-promoter systems were built using four promoters (PyvyD, P43, PaprE, and PspoVG) with relatively high BlAase expression levels to boost BlAase output, with the engine of promoter PaprE-PyvyD reaching 502.11 U/mL. The activity of BlAase was also increased (568.59 U/mL) by modifying key portions of the PaprE-PyvyD promoter. Third, when the ribosome binding site (RBS) sequence of promoter PyvyD was replaced, BlAase activity reached 790.1 U/mL, which was 2.27 times greater than the original promoter P43 strain. After 36 h of cultivation, the BlAase expression level in a 10 L fermenter reached 2163.09 U/mL, which was 6.2 times greater than the initial strain using promoter P43. Moreover, the application potential of BlAase on acrylamide migration in potato chips was evaluated. Results showed that 89.50% of acrylamide in fried potato chips could be removed when combined with blanching and BlAase treatment. These findings revealed that combining transcription and translation techniques are effective strategies to boost recombinant protein output, and BlAase can be a great candidate for controlling acrylamide in food processing.
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Affiliation(s)
| | | | | | | | | | | | - Fengxia Lu
- Correspondence: ; Tel.: +86-25-8439-5963
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17
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Patel JR, Oh J, Wang S, Crawford JM, Isaacs FJ. Cross-kingdom expression of synthetic genetic elements promotes discovery of metabolites in the human microbiome. Cell 2022; 185:1487-1505.e14. [PMID: 35366417 PMCID: PMC10619838 DOI: 10.1016/j.cell.2022.03.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 02/04/2022] [Accepted: 03/07/2022] [Indexed: 12/12/2022]
Abstract
Small molecules encoded by biosynthetic pathways mediate cross-species interactions and harbor untapped potential, which has provided valuable compounds for medicine and biotechnology. Since studying biosynthetic gene clusters in their native context is often difficult, alternative efforts rely on heterologous expression, which is limited by host-specific metabolic capacity and regulation. Here, we describe a computational-experimental technology to redesign genes and their regulatory regions with hybrid elements for cross-species expression in Gram-negative and -positive bacteria and eukaryotes, decoupling biosynthetic capacity from host-range constraints to activate silenced pathways. These synthetic genetic elements enabled the discovery of a class of microbiome-derived nucleotide metabolites-tyrocitabines-from Lactobacillus iners. Tyrocitabines feature a remarkable orthoester-phosphate, inhibit translational activity, and invoke unexpected biosynthetic machinery, including a class of "Amadori synthases" and "abortive" tRNA synthetases. Our approach establishes a general strategy for the redesign, expression, mobilization, and characterization of genetic elements in diverse organisms and communities.
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Affiliation(s)
- Jaymin R Patel
- Department of Molecular, Cellular, & Developmental Biology, Yale University, New Haven, CT, USA; Systems Biology Institute, Yale University, West Haven, CT, USA; Institute of Biomolecular Design and Discovery, Yale University, West Haven, CT, USA
| | - Joonseok Oh
- Institute of Biomolecular Design and Discovery, Yale University, West Haven, CT, USA; Department of Chemistry, Yale University, New Haven, CT, USA
| | - Shenqi Wang
- Department of Molecular, Cellular, & Developmental Biology, Yale University, New Haven, CT, USA; Systems Biology Institute, Yale University, West Haven, CT, USA
| | - Jason M Crawford
- Institute of Biomolecular Design and Discovery, Yale University, West Haven, CT, USA; Department of Chemistry, Yale University, New Haven, CT, USA; Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT, USA.
| | - Farren J Isaacs
- Department of Molecular, Cellular, & Developmental Biology, Yale University, New Haven, CT, USA; Systems Biology Institute, Yale University, West Haven, CT, USA; Department of Biomedical Engineering, Yale University, New Haven, CT, USA.
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18
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Smith C, Canestrari JG, Wang AJ, Champion MM, Derbyshire KM, Gray TA, Wade JT. Pervasive translation in Mycobacterium tuberculosis. eLife 2022; 11:e73980. [PMID: 35343439 PMCID: PMC9094748 DOI: 10.7554/elife.73980] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 03/25/2022] [Indexed: 11/13/2022] Open
Abstract
Most bacterial ORFs are identified by automated prediction algorithms. However, these algorithms often fail to identify ORFs lacking canonical features such as a length of >50 codons or the presence of an upstream Shine-Dalgarno sequence. Here, we use ribosome profiling approaches to identify actively translated ORFs in Mycobacterium tuberculosis. Most of the ORFs we identify have not been previously described, indicating that the M. tuberculosis transcriptome is pervasively translated. The newly described ORFs are predominantly short, with many encoding proteins of ≤50 amino acids. Codon usage of the newly discovered ORFs suggests that most have not been subject to purifying selection, and hence are unlikely to contribute to cell fitness. Nevertheless, we identify 90 new ORFs (median length of 52 codons) that bear the hallmarks of purifying selection. Thus, our data suggest that pervasive translation of short ORFs in Mycobacterium tuberculosis serves as a rich source for the evolution of new functional proteins.
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Affiliation(s)
- Carol Smith
- Wadsworth Center, Division of Genetics, New York State Department of HealthAlbanyUnited States
| | - Jill G Canestrari
- Wadsworth Center, Division of Genetics, New York State Department of HealthAlbanyUnited States
| | - Archer J Wang
- Wadsworth Center, Division of Genetics, New York State Department of HealthAlbanyUnited States
| | - Matthew M Champion
- Department of Chemistry and Biochemistry, University of Notre DameNotre DameUnited States
| | - Keith M Derbyshire
- Wadsworth Center, Division of Genetics, New York State Department of HealthAlbanyUnited States
- Department of Biomedical Sciences, School of Public Health, University at AlbanyNew YorkUnited States
| | - Todd A Gray
- Wadsworth Center, Division of Genetics, New York State Department of HealthAlbanyUnited States
- Department of Biomedical Sciences, School of Public Health, University at AlbanyNew YorkUnited States
| | - Joseph T Wade
- Wadsworth Center, Division of Genetics, New York State Department of HealthAlbanyUnited States
- Department of Biomedical Sciences, School of Public Health, University at AlbanyNew YorkUnited States
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19
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Sen S, Patel A, Gola KK. Design of a Toolbox of RNA Thermometers. Methods Mol Biol 2022; 2518:125-133. [PMID: 35666443 DOI: 10.1007/978-1-0716-2421-0_8] [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: 06/15/2023]
Abstract
RNA thermometers are RNA regulatory elements that convert temperature into a functional biological response through a temperature-induced conformational change. These regulatory elements have been investigated in numerous natural contexts and have been designed for synthetic biology as well. A basic challenge has been the design of an RNA thermometer whose final activity in response to temperature matches a prespecified response, in terms of its sensitivity, threshold, and leakiness. This chapter provides a methodology for the design of a toolbox of RNA thermometers. We describe considerations for the conceptual design, a computational assessment, and strategies for experimental synthesis and measurement.
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Affiliation(s)
- Shaunak Sen
- Department of Electrical Engineering, IIT Delhi, New Delhi, India.
| | - Abhilash Patel
- Department of Bioengineering, Imperial College, London, UK
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20
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McNutt ZA, Gandhi MD, Shatoff EA, Roy B, Devaraj A, Bundschuh R, Fredrick K. Comparative Analysis of anti-Shine- Dalgarno Function in Flavobacterium johnsoniae and Escherichia coli. Front Mol Biosci 2021; 8:787388. [PMID: 34966783 PMCID: PMC8710568 DOI: 10.3389/fmolb.2021.787388] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/08/2021] [Indexed: 12/03/2022] Open
Abstract
The anti-Shine-Dalgarno (ASD) sequence of 16S rRNA is highly conserved across Bacteria, and yet usage of Shine-Dalgarno (SD) sequences in mRNA varies dramatically, depending on the lineage. Here, we compared the effects of ASD mutagenesis in Escherichia coli, a Gammaproteobacteria which commonly employs SD sequences, and Flavobacterium johnsoniae, a Bacteroidia which rarely does. In E. coli, 30S subunits carrying any single substitution at positions 1,535–1,539 confer dominant negative phenotypes, whereas subunits with mutations at positions 1,540–1,542 are sufficient to support cell growth. These data suggest that CCUCC (1,535–1,539) represents the functional core of the element in E. coli. In F. johnsoniae, deletion of three ribosomal RNA (rrn) operons slowed growth substantially, a phenotype largely rescued by a plasmid-borne copy of the rrn operon. Using this complementation system, we found that subunits with single mutations at positions 1,535–1,537 are as active as control subunits, in sharp contrast to the E. coli results. Moreover, subunits with quadruple substitution or complete replacement of the ASD retain substantial, albeit reduced, activity. Sedimentation analysis revealed that these mutant subunits are overrepresented in the subunit fractions and underrepresented in polysome fractions, suggesting some defect in 30S biogenesis and/or translation initiation. Nonetheless, our collective data indicate that the ASD plays a much smaller role in F. johnsoniae than in E. coli, consistent with SD usage in the two organisms.
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Affiliation(s)
- Zakkary A McNutt
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, United States.,Center for RNA Biology, The Ohio State University, Columbus, OH, United States
| | - Mai D Gandhi
- Department of Microbiology, The Ohio State University, Columbus, OH, United States
| | - Elan A Shatoff
- Center for RNA Biology, The Ohio State University, Columbus, OH, United States.,Department of Physics, The Ohio State University, Columbus, OH, United States
| | - Bappaditya Roy
- Center for RNA Biology, The Ohio State University, Columbus, OH, United States.,Department of Microbiology, The Ohio State University, Columbus, OH, United States
| | - Aishwarya Devaraj
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, United States.,Center for RNA Biology, The Ohio State University, Columbus, OH, United States
| | - Ralf Bundschuh
- Center for RNA Biology, The Ohio State University, Columbus, OH, United States.,Department of Physics, The Ohio State University, Columbus, OH, United States.,Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, United, States.,Division of Hematology, Department of Internal Medicine, The Ohio State University, Columbus, OH, United States
| | - Kurt Fredrick
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, United States.,Center for RNA Biology, The Ohio State University, Columbus, OH, United States.,Department of Microbiology, The Ohio State University, Columbus, OH, United States
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21
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Lenz P, Hilgers F, Burmeister A, Zimmermann L, Volkenborn K, Grünberger A, Kohlheyer D, Drepper T, Jaeger KE, Knapp A. The iSplit GFP assay detects intracellular recombinant proteins in Bacillus subtilis. Microb Cell Fact 2021; 20:174. [PMID: 34488765 PMCID: PMC8419962 DOI: 10.1186/s12934-021-01663-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 08/19/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Bacillus subtilis is one of the most important microorganisms for recombinant protein production. It possesses the GRAS (generally recognized as safe) status and a potent protein secretion capacity. Secretory protein production greatly facilitates downstream processing and thus significantly reduces costs. However, not all heterologous proteins are secreted and intracellular production poses difficulties for quantification. To tackle this problem, we have established a so-called intracellular split GFP (iSplit GFP) assay in B. subtilis as a tool for the in vivo protein detection during expression in batch cultures and at a single-cell level. For the iSplit GFP assay, the eleventh β-sheet of sfGFP is fused to a target protein and can complement a detector protein consisting of the respective truncated sfGFP (GFP1-10) to form fluorescent holo-GFP. RESULTS As proof of concept, the GFP11-tag was fused C-terminally to the E. coli β-glucuronidase GUS, resulting in fusion protein GUS11. Variable GUS and GUS11 production levels in B. subtilis were achieved by varying the ribosome binding site via spacers of increasing lengths (4-12 nucleotides) for the GUS-encoding gene. Differences in intracellular enzyme accumulation were determined by measuring the GUS11 enzymatic activity and subsequently by adding the detector protein to respective cell extracts. Moreover, the detector protein was co-produced with the GUS11 using a two-plasmid system, which enabled the in vivo detection and online monitoring of glucuronidase production. Using this system in combination with flow cytometry and microfluidics, we were able to monitor protein production at a single-cell level thus yielding information about intracellular protein distribution and culture heterogeneity. CONCLUSION Our results demonstrate that the iSplit GFP assay is suitable for the detection, quantification and online monitoring of recombinant protein production in B. subtilis during cultivation as well as for analyzing production heterogeneity and intracellular localization at a single-cell level.
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Affiliation(s)
- Patrick Lenz
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Fabienne Hilgers
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Alina Burmeister
- Institute of Bio- and Geoscience, IBG-1: Biotechnology: Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
- Multiscale Bioengineering, Bielefeld University, 33615, Bielefeld, Germany
| | - Leonie Zimmermann
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Kristina Volkenborn
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Alexander Grünberger
- Institute of Bio- and Geoscience, IBG-1: Biotechnology: Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
- Multiscale Bioengineering, Bielefeld University, 33615, Bielefeld, Germany
| | - Dietrich Kohlheyer
- Institute of Bio- and Geoscience, IBG-1: Biotechnology: Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
- RWTH Aachen University, Microscale Bioengineering (AVT.MSB), 52074, Aachen, Germany
| | - Thomas Drepper
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, 52425, Jülich, Germany
- Institute of Bio- and Geoscience, IBG-1: Biotechnology: Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Andreas Knapp
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, 52425, Jülich, Germany.
- Castrol Germany GmbH, 41179, Mönchengladbach, Germany.
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22
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Marjanovic A, Rozeboom HJ, de Vries MS, Mayer C, Otzen M, Wijma HJ, Janssen DB. Catalytic and structural properties of ATP-dependent caprolactamase from Pseudomonas jessenii. Proteins 2021; 89:1079-1098. [PMID: 33826169 PMCID: PMC8453981 DOI: 10.1002/prot.26082] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 03/04/2021] [Accepted: 03/22/2021] [Indexed: 12/14/2022]
Abstract
Caprolactamase is the first enzyme in the caprolactam degradation pathway of Pseudomonas jessenii. It is composed of two subunits (CapA and CapB) and sequence-related to other ATP-dependent enzymes involved in lactam hydrolysis, like 5-oxoprolinases and hydantoinases. Low sequence similarity also exists with ATP-dependent acetone- and acetophenone carboxylases. The caprolactamase was produced in Escherichia coli, isolated by His-tag affinity chromatography, and subjected to functional and structural studies. Activity toward caprolactam required ATP and was dependent on the presence of bicarbonate in the assay buffer. The hydrolysis product was identified as 6-aminocaproic acid. Quantum mechanical modeling indicated that the hydrolysis of caprolactam was highly disfavored (ΔG0 '= 23 kJ/mol), which explained the ATP dependence. A crystal structure showed that the enzyme exists as an (αβ)2 tetramer and revealed an ATP-binding site in CapA and a Zn-coordinating site in CapB. Mutations in the ATP-binding site of CapA (D11A and D295A) significantly reduced product formation. Mutants with substitutions in the metal binding site of CapB (D41A, H99A, D101A, and H124A) were inactive and less thermostable than the wild-type enzyme. These residues proved to be essential for activity and on basis of the experimental findings we propose possible mechanisms for ATP-dependent lactam hydrolysis.
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Affiliation(s)
- Antonija Marjanovic
- Biotransformation and Biocatalysis, Groningen Biomolecular Sciences and Biotechnology Institute (GBB)University of GroningenGroningenThe Netherlands
| | - Henriëtte J. Rozeboom
- Biotransformation and Biocatalysis, Groningen Biomolecular Sciences and Biotechnology Institute (GBB)University of GroningenGroningenThe Netherlands
| | - Meintje S. de Vries
- Biotransformation and Biocatalysis, Groningen Biomolecular Sciences and Biotechnology Institute (GBB)University of GroningenGroningenThe Netherlands
| | - Clemens Mayer
- Biomolecular Chemistry and Catalysis, Stratingh Institute for ChemistryUniversity of GroningenGroningenThe Netherlands
| | - Marleen Otzen
- Biotransformation and Biocatalysis, Groningen Biomolecular Sciences and Biotechnology Institute (GBB)University of GroningenGroningenThe Netherlands
| | | | - Dick B. Janssen
- Biotransformation and Biocatalysis, Groningen Biomolecular Sciences and Biotechnology Institute (GBB)University of GroningenGroningenThe Netherlands
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23
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Voedts H, Dorchêne D, Lodge A, Vollmer W, Arthur M, Hugonnet JE. Role of endopeptidases in peptidoglycan synthesis mediated by alternative cross-linking enzymes in Escherichia coli. EMBO J 2021; 40:e108126. [PMID: 34382698 DOI: 10.15252/embj.2021108126] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 07/22/2021] [Accepted: 07/24/2021] [Indexed: 12/20/2022] Open
Abstract
Bacteria resist to the turgor pressure of the cytoplasm through a net-like macromolecule, the peptidoglycan, made of glycan strands connected via peptides cross-linked by penicillin-binding proteins (PBPs). We recently reported the emergence of β-lactam resistance resulting from a bypass of PBPs by the YcbB L,D-transpeptidase (LdtD), which form chemically distinct 3→3 cross-links compared to 4→3 formed by PBPs. Here we show that peptidoglycan expansion requires controlled hydrolysis of cross-links and identify among eight endopeptidase paralogues the minimum enzyme complements essential for bacterial growth with 4→3 (MepM) and 3→3 (MepM and MepK) cross-links. Purified Mep endopeptidases unexpectedly displayed a 4→3 and 3→3 dual specificity implying recognition of a common motif in the two cross-link types. Uncoupling of the polymerization of glycan chains from the 4→3 cross-linking reaction was found to facilitate the bypass of PBPs by YcbB. These results illustrate the plasticity of the peptidoglycan polymerization machinery in response to the selective pressure of β-lactams.
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Affiliation(s)
- Henri Voedts
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université de Paris, Paris, France
| | - Delphine Dorchêne
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université de Paris, Paris, France
| | - Adam Lodge
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle Upon Tyne, UK
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle Upon Tyne, UK
| | - Michel Arthur
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université de Paris, Paris, France
| | - Jean-Emmanuel Hugonnet
- Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université de Paris, Paris, France
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24
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Characterization of the roles of activated charcoal and Chelex in the induction of PrfA regulon expression in complex medium. PLoS One 2021; 16:e0250989. [PMID: 33914817 PMCID: PMC8084165 DOI: 10.1371/journal.pone.0250989] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 04/16/2021] [Indexed: 11/21/2022] Open
Abstract
The foodborne pathogen Listeria monocytogenes is able to survive across a wide range of intra- and extra-host environments by appropriately modulating gene expression patterns in response to different stimuli. Positive Regulatory Factor A (PrfA) is the major transcriptional regulator of virulence gene expression in L. monocytogenes. It has long been known that activated charcoal is required to induce the expression of PrfA-regulated genes in complex media, such as Brain Heart Infusion (BHI), but not in chemically defined media. In this study, we show that the expression of the PrfA-regulated hly, which encodes listeriolysin O, is induced 5- and 8-fold in L. monocytogenes cells grown in Chelex-treated BHI (Ch-BHI) and in the presence of activated charcoal (AC-BHI), respectively, relative to cells grown in BHI medium. Specifically, we show that metal ions present in BHI broth plays a role in the reduced expression of the PrfA regulon. In addition, we show that expression of hly is induced when the levels of bioavailable extra- or intercellular iron are reduced. L. monocytogenes cells grown Ch-BHI and AC-BHI media showed similar levels of resistance to the iron-activated antibiotic, streptonigrin, indicating that activated charcoal reduces the intracellular labile iron pool. Metal depletion and exogenously added glutathione contributed synergistically to PrfA-regulated gene expression since glutathione further increased hly expression in metal-depleted BHI but not in BHI medium. Analyses of transcriptional reporter fusion expression patterns revealed that genes in the PrfA regulon are differentially expressed in response to metal depletion, metal excess and exogenous glutathione. Our results suggest that metal ion abundance plays a role in modulating expression of PrfA-regulated virulence genes in L. monocytogenes.
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25
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Jha V, Roy B, Jahagirdar D, McNutt ZA, Shatoff EA, Boleratz BL, Watkins DE, Bundschuh R, Basu K, Ortega J, Fredrick K. Structural basis of sequestration of the anti-Shine-Dalgarno sequence in the Bacteroidetes ribosome. Nucleic Acids Res 2021; 49:547-567. [PMID: 33330920 PMCID: PMC7797042 DOI: 10.1093/nar/gkaa1195] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 11/18/2020] [Accepted: 11/24/2020] [Indexed: 11/25/2022] Open
Abstract
Genomic studies have indicated that certain bacterial lineages such as the Bacteroidetes lack Shine-Dalgarno (SD) sequences, and yet with few exceptions ribosomes of these organisms carry the canonical anti-SD (ASD) sequence. Here, we show that ribosomes purified from Flavobacterium johnsoniae, a representative of the Bacteroidetes, fail to recognize the SD sequence of mRNA in vitro. A cryo-electron microscopy structure of the complete 70S ribosome from F. johnsoniae at 2.8 Å resolution reveals that the ASD is sequestered by ribosomal proteins bS21, bS18 and bS6, explaining the basis of ASD inhibition. The structure also uncovers a novel ribosomal protein—bL38. Remarkably, in F. johnsoniae and many other Flavobacteriia, the gene encoding bS21 contains a strong SD, unlike virtually all other genes. A subset of Flavobacteriia have an alternative ASD, and in these organisms the fully complementary sequence lies upstream of the bS21 gene, indicative of natural covariation. In other Bacteroidetes classes, strong SDs are frequently found upstream of the genes for bS21 and/or bS18. We propose that these SDs are used as regulatory elements, enabling bS21 and bS18 to translationally control their own production.
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Affiliation(s)
- Vikash Jha
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada.,Centre for Structural Biology, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - Bappaditya Roy
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.,Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Dushyant Jahagirdar
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada.,Centre for Structural Biology, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - Zakkary A McNutt
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.,Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Elan A Shatoff
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.,Department of Physics, The Ohio State University, Columbus, OH 43210, USA
| | - Bethany L Boleratz
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Dean E Watkins
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
| | - Ralf Bundschuh
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.,Department of Physics, The Ohio State University, Columbus, OH 43210, USA.,Department of Chemistry & Biochemistry, Division of Hematology, The Ohio State University, Columbus, OH 43210, USA
| | - Kaustuv Basu
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada.,Centre for Structural Biology, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - Joaquin Ortega
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada.,Centre for Structural Biology, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - Kurt Fredrick
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.,Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.,Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
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26
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Wen JD, Kuo ST, Chou HHD. The diversity of Shine-Dalgarno sequences sheds light on the evolution of translation initiation. RNA Biol 2020; 18:1489-1500. [PMID: 33349119 DOI: 10.1080/15476286.2020.1861406] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Shine-Dalgarno (SD) sequences, the core element of prokaryotic ribosome-binding sites, facilitate mRNA translation by base-pair interaction with the anti-SD (aSD) sequence of 16S rRNA. In contrast to this paradigm, an inspection of thousands of prokaryotic species unravels tremendous SD sequence diversity both within and between genomes, whereas aSD sequences remain largely static. The pattern has led many to suggest unidentified mechanisms for translation initiation. Here we review known translation-initiation pathways in prokaryotes. Moreover, we seek to understand the cause and consequence of SD diversity through surveying recent advances in biochemistry, genomics, and high-throughput genetics. These findings collectively show: (1) SD:aSD base pairing is beneficial but nonessential to translation initiation. (2) The 5' untranslated region of mRNA evolves dynamically and correlates with organismal phylogeny and ecological niches. (3) Ribosomes have evolved distinct usage of translation-initiation pathways in different species. We propose a model portraying the SD diversity shaped by optimization of gene expression, adaptation to environments and growth demands, and the species-specific prerequisite of ribosomes to initiate translation. The model highlights the coevolution of ribosomes and mRNA features, leading to functional customization of the translation apparatus in each organism.
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Affiliation(s)
- Jin-Der Wen
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan.,Genome and Systems Biology Degree Program, Academia Sinica and National Taiwan University, Taipei, Taiwan
| | - Syue-Ting Kuo
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Hsin-Hung David Chou
- Genome and Systems Biology Degree Program, Academia Sinica and National Taiwan University, Taipei, Taiwan.,Department of Life Science, National Taiwan University, Taipei, Taiwan
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27
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Reis AC, Salis HM. An Automated Model Test System for Systematic Development and Improvement of Gene Expression Models. ACS Synth Biol 2020; 9:3145-3156. [PMID: 33054181 DOI: 10.1021/acssynbio.0c00394] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Gene expression models greatly accelerate the engineering of synthetic metabolic pathways and genetic circuits by predicting sequence-function relationships and reducing trial-and-error experimentation. However, developing models with more accurate predictions remains a significant challenge. Here we present a model test system that combines advanced statistics, machine learning, and a database of 9862 characterized genetic systems to automatically quantify model accuracies, accept or reject mechanistic hypotheses, and identify areas for model improvement. We also introduce model capacity, a new information theoretic metric for correct cross-data-set comparisons. We demonstrate the model test system by comparing six models of translation initiation rate, evaluating 100 mechanistic hypotheses, and uncovering new sequence determinants that control protein expression levels. We then applied these results to develop a biophysical model of translation initiation rate with significant improvements in accuracy. Automated model test systems will dramatically accelerate the development of gene expression models, and thereby transition synthetic biology into a mature engineering discipline.
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28
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Oliveira Paiva AM, van Eijk E, Friggen AH, Weigel C, Smits WK. Identification of the Unwinding Region in the Clostridioides difficile Chromosomal Origin of Replication. Front Microbiol 2020; 11:581401. [PMID: 33133049 PMCID: PMC7561715 DOI: 10.3389/fmicb.2020.581401] [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: 07/08/2020] [Accepted: 08/31/2020] [Indexed: 12/14/2022] Open
Abstract
Faithful DNA replication is crucial for viability of cells across all kingdoms. Targeting DNA replication is a viable strategy for inhibition of bacterial pathogens. Clostridioides difficile is an important enteropathogen that causes potentially fatal intestinal inflammation. Knowledge about DNA replication in this organism is limited and no data is available on the very first steps of DNA replication. Here, we use a combination of in silico predictions and in vitro experiments to demonstrate that C. difficile employs a bipartite origin of replication that shows DnaA-dependent melting at oriC2, located in the dnaA-dnaN intergenic region. Analysis of putative origins of replication in different clostridia suggests that the main features of the origin architecture are conserved. This study is the first to characterize aspects of the origin region of C. difficile and contributes to our understanding of the initiation of DNA replication in clostridia.
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Affiliation(s)
- Ana M Oliveira Paiva
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, Netherlands.,Centre for Microbial Cell Biology, Leiden, Netherlands
| | - Erika van Eijk
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, Netherlands
| | - Annemieke H Friggen
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, Netherlands
| | - Christoph Weigel
- Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Wiep Klaas Smits
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, Netherlands.,Centre for Microbial Cell Biology, Leiden, Netherlands
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29
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Wang F, Gao Y, Yang G. Recent advances in synthetic biology of cyanobacteria for improved chemicals production. Bioengineered 2020; 11:1208-1220. [PMID: 33124500 PMCID: PMC8291842 DOI: 10.1080/21655979.2020.1837458] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Cyanobacteria are Gram-negative photoautotrophic prokaryotes and have shown great importance to the Earth’s ecology. Based on their capability in oxygenic photosynthesis and genetic merits, they can be engineered as microbial chassis for direct conversion of carbon dioxide to value-added biofuels and chemicals. In the last decades, attempts have given to the application of synthetic biology tools and approaches in the development of cyanobacterial cell factories. Despite the successful proof-of-principle studies, large-scale application is still a technical challenge due to low yields of bioproducts. Therefore, recent efforts are underway to characterize and develop genetic regulatory parts and strategies for the synthetic biology applications in cyanobacteria. In this review, we present the recent advancements and application in cyanobacterial synthetic biology toolboxes. We also discuss the limitations and future perspectives for using such novel tools in cyanobacterial biotechnology.
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Affiliation(s)
- Fen Wang
- Department of Surgery, College of Medicine, University of Florida , Gainesville, FL, USA
| | - Yuanyuan Gao
- Jining Academy of Agricultural Science , Jining, Shandong, China
| | - Guang Yang
- Department of Aging and Geriatric Research, Institute on Aging, University of Florida , Gainesville, FL, USA
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30
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Volkenborn K, Kuschmierz L, Benz N, Lenz P, Knapp A, Jaeger KE. The length of ribosomal binding site spacer sequence controls the production yield for intracellular and secreted proteins by Bacillus subtilis. Microb Cell Fact 2020; 19:154. [PMID: 32727460 PMCID: PMC7392706 DOI: 10.1186/s12934-020-01404-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 07/13/2020] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Bacillus subtilis is widely used for the industrial production of recombinant proteins, mainly due to its high secretion capacity, but higher production yields can be achieved only if bottlenecks are removed. To this end, a crucial process is translation initiation which takes place at the ribosome binding site enclosing the Shine Dalgarno sequence, the start codon of the target gene and a short spacer sequence in between. Here, we have studied the effects of varying spacer sequence lengths in vivo on the production yield of different intra- and extracellular proteins. RESULTS The shuttle vector pBSMul1 containing the strong constitutive promoter PHpaII and the optimal Shine Dalgarno sequence TAAGGAGG was used as a template to construct a series of vectors with spacer lengths varying from 4 to 12 adenosines. For the intracellular proteins GFPmut3 and β-glucuronidase, an increase of spacer lengths from 4 to 7-9 nucleotides resulted in a gradual increase of product yields up to 27-fold reaching a plateau for even longer spacers. The production of secreted proteins was tested with cutinase Cut and swollenin EXLX1 which were N-terminally fused to one of the Sec-dependent signal peptides SPPel, SPEpr or SPBsn. Again, longer spacer sequences resulted in up to tenfold increased yields of extracellular proteins. Fusions with signal peptides SPPel or SPBsn revealed the highest production yields with spacers of 7-10nt length. Remarkably, fusions with SPEpr resulted in a twofold lower production yield with 6 or 7nt spacers reaching a maximum with 10-12nt spacers. This pattern was observed for both secreted proteins fused to SPEpr indicating a dominant role also of the nucleotide sequence encoding the respective signal peptide for translation initiation. This conclusion was corroborated by RT qPCR revealing only slightly different amounts of transcript. Also, the effect of a putative alternative translation initiation site could be ruled out. CONCLUSION Our results confirm the importance of the 5' end sequence of a target gene for translation initiation. Optimizing production yields thus may require screenings for optimal spacer sequence lengths. In case of secreted proteins, the 5' sequence encoding the signal peptide for Sec-depended secretion should also be considered.
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Affiliation(s)
- Kristina Volkenborn
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.,Bioeconomy Science Center (BioSC), C/o Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Laura Kuschmierz
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.,Environmental Microbiology and Biotechnology-Molecular Enzyme Technology and Biochemistry, University Duisburg-Essen, 45141, Essen, Germany
| | - Nuka Benz
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.,Bioeconomy Science Center (BioSC), C/o Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Patrick Lenz
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Andreas Knapp
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany. .,Bioeconomy Science Center (BioSC), C/o Forschungszentrum Jülich, 52425, Jülich, Germany.
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.,Institute of Bio- and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.,Bioeconomy Science Center (BioSC), C/o Forschungszentrum Jülich, 52425, Jülich, Germany
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31
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High-yield and plasmid-free biocatalytic production of 5-methylpyrazine-2-carboxylic acid by combinatorial genetic elements engineering and genome engineering of Escherichia coli. Enzyme Microb Technol 2020; 134:109488. [DOI: 10.1016/j.enzmictec.2019.109488] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 11/17/2019] [Accepted: 12/08/2019] [Indexed: 02/06/2023]
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32
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Abdallah II, Xue D, Pramastya H, van Merkerk R, Setroikromo R, Quax WJ. A regulated synthetic operon facilitates stable overexpression of multigene terpenoid pathway in Bacillus subtilis. ACTA ACUST UNITED AC 2020; 47:243-249. [DOI: 10.1007/s10295-019-02257-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 12/14/2019] [Indexed: 01/17/2023]
Abstract
Abstract
The creation of microbial cell factories for sustainable production of natural products is important for medical and industrial applications. This requires stable expression of biosynthetic pathways in a host organism with favorable fermentation properties such as Bacillus subtilis. The aim of this study is to construct B. subtilis strains that produce valuable terpenoid compounds by overexpressing the innate methylerythritol phosphate (MEP) pathway. A synthetic operon allowing the concerted and regulated expression of multiple genes was developed. Up to 8 genes have been combined in this operon and a stably inherited plasmid-based vector was constructed resulting in a high production of C30 carotenoids. For this, two vectors were examined, one with rolling circle replication and another with theta replication. Theta-replication constructs were clearly superior in structural and segregational stability compared to rolling circle constructs. A strain overexpressing all eight genes of the MEP pathway on a theta-replicating plasmid clearly produced the highest level of carotenoids. The level of transcription for each gene in the operon was similar as RT-qPCR analysis indicated. Hence, that corresponding strain can be used as a stable cell factory for production of terpenoids. This is the first report of merging and stably expressing this large-size operon (eight genes) from a plasmid-based system in B. subtilis enabling high C30 carotenoid production.
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Affiliation(s)
- Ingy I Abdallah
- grid.4830.f 0000 0004 0407 1981 Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy University of Groningen Antonius Deusinglaan 1 9713 AV Groningen The Netherlands
| | - Dan Xue
- grid.4830.f 0000 0004 0407 1981 Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy University of Groningen Antonius Deusinglaan 1 9713 AV Groningen The Netherlands
| | - Hegar Pramastya
- grid.4830.f 0000 0004 0407 1981 Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy University of Groningen Antonius Deusinglaan 1 9713 AV Groningen The Netherlands
- grid.434933.a 0000 0004 1808 0563 Pharmaceutical Biology Research Group, School of Pharmacy Institut Teknologi Bandung 40132 Bandung Indonesia
| | - Ronald van Merkerk
- grid.4830.f 0000 0004 0407 1981 Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy University of Groningen Antonius Deusinglaan 1 9713 AV Groningen The Netherlands
| | - Rita Setroikromo
- grid.4830.f 0000 0004 0407 1981 Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy University of Groningen Antonius Deusinglaan 1 9713 AV Groningen The Netherlands
| | - Wim J Quax
- grid.4830.f 0000 0004 0407 1981 Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy University of Groningen Antonius Deusinglaan 1 9713 AV Groningen The Netherlands
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33
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Vecchione S, Fritz G. CRIMoClo plasmids for modular assembly and orthogonal chromosomal integration of synthetic circuits in Escherichia coli. J Biol Eng 2019; 13:92. [PMID: 31798686 PMCID: PMC6883643 DOI: 10.1186/s13036-019-0218-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 10/23/2019] [Indexed: 01/09/2023] Open
Abstract
Background Synthetic biology heavily depends on rapid and simple techniques for DNA engineering, such as Ligase Cycling Reaction (LCR), Gibson assembly and Golden Gate assembly, all of which allow for fast, multi-fragment DNA assembly. A major enhancement of Golden Gate assembly is represented by the Modular Cloning (MoClo) system that allows for simple library propagation and combinatorial construction of genetic circuits from reusable parts. Yet, one limitation of the MoClo system is that all circuits are assembled in low- and medium copy plasmids, while a rapid route to chromosomal integration is lacking. To overcome this bottleneck, here we took advantage of the conditional-replication, integration, and modular (CRIM) plasmids, which can be integrated in single copies into the chromosome of Escherichia coli and related bacteria by site-specific recombination at different phage attachment (att) sites. Results By combining the modularity of the MoClo system with the CRIM plasmids features we created a set of 32 novel CRIMoClo plasmids and benchmarked their suitability for synthetic biology applications. Using CRIMoClo plasmids we assembled and integrated a given genetic circuit into four selected phage attachment sites. Analyzing the behavior of these circuits we found essentially identical expression levels, indicating orthogonality of the loci. Using CRIMoClo plasmids and four different reporter systems, we illustrated a framework that allows for a fast and reliable sequential integration at the four selected att sites. Taking advantage of four resistance cassettes the procedure did not require recombination events between each round of integration. Finally, we assembled and genomically integrated synthetic ECF σ factor/anti-σ switches with high efficiency, showing that the growth defects observed for circuits encoded on medium-copy plasmids were alleviated. Conclusions The CRIMoClo system enables the generation of genetic circuits from reusable, MoClo-compatible parts and their integration into 4 orthogonal att sites into the genome of E. coli. Utilizing four different resistance modules the CRIMoClo system allows for easy, fast, and reliable multiple integrations. Moreover, utilizing CRIMoClo plasmids and MoClo reusable parts, we efficiently integrated and alleviated the toxicity of plasmid-borne circuits. Finally, since CRIMoClo framework allows for high flexibility, it is possible to utilize plasmid-borne and chromosomally integrated circuits simultaneously. This increases our ability to permute multiple genetic modules and allows for an easier design of complex synthetic metabolic pathways in E. coli.
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Affiliation(s)
- Stefano Vecchione
- LOEWE Center for Synthetic Microbiology, Philipps-University Marburg, Hans-Meerwein Str. 6, 35032 Marburg, Germany
| | - Georg Fritz
- LOEWE Center for Synthetic Microbiology, Philipps-University Marburg, Hans-Meerwein Str. 6, 35032 Marburg, Germany
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34
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Baez WD, Roy B, McNutt ZA, Shatoff EA, Chen S, Bundschuh R, Fredrick K. Global analysis of protein synthesis in Flavobacterium johnsoniae reveals the use of Kozak-like sequences in diverse bacteria. Nucleic Acids Res 2019; 47:10477-10488. [PMID: 31602466 PMCID: PMC6847099 DOI: 10.1093/nar/gkz855] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 09/16/2019] [Accepted: 09/30/2019] [Indexed: 12/31/2022] Open
Abstract
In all cells, initiation of translation is tuned by intrinsic features of the mRNA. Here, we analyze translation in Flavobacterium johnsoniae, a representative of the Bacteroidetes. Members of this phylum naturally lack Shine-Dalgarno (SD) sequences in their mRNA, and yet their ribosomes retain the conserved anti-SD sequence. Translation initiation is tuned by mRNA secondary structure and by the identities of several key nucleotides upstream of the start codon. Positive determinants include adenine at position -3, reminiscent of the Kozak sequence of Eukarya. Comparative analysis of Escherichia coli reveals use of the same Kozak-like sequence to enhance initiation, suggesting an ancient and widespread mechanism. Elimination of contacts between A-3 and the conserved β-hairpin of ribosomal protein uS7 fails to diminish the contribution of A-3 to initiation, suggesting an indirect mode of recognition. Also, we find that, in the Bacteroidetes, the trinucleotide AUG is underrepresented in the vicinity of the start codon, which presumably helps compensate for the absence of SD sequences in these organisms.
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Affiliation(s)
- William D Baez
- Department of Physics, The Ohio State University, Columbus, OH 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Bappaditya Roy
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
| | - Zakkary A McNutt
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Elan A Shatoff
- Department of Physics, The Ohio State University, Columbus, OH 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
| | - Shicheng Chen
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
| | - Ralf Bundschuh
- Department of Physics, The Ohio State University, Columbus, OH 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
- Department of Chemistry and Biochemistry, Division of Hematology, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Kurt Fredrick
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
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35
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Liu D, Huang C, Guo J, Zhang P, Chen T, Wang Z, Zhao X. Development and characterization of a CRISPR/Cas9n-based multiplex genome editing system for Bacillus subtilis. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:197. [PMID: 31572493 PMCID: PMC6764132 DOI: 10.1186/s13068-019-1537-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 08/04/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Metabolic engineering has expanded from a focus on designs requiring a small number of genetic modifications to increasingly complex designs driven by advances in multiplex genome editing technologies. However, simultaneously modulating multiple genes on the chromosome remains challenging in Bacillus subtilis. Thus, developing an efficient and convenient method for B. subtilis multiplex genome editing is imperative. RESULTS Here, we developed a CRISPR/Cas9n-based multiplex genome editing system for iterative genome editing in B. subtilis. This system enabled us to introduce various types of genomic modifications with more satisfying efficiency than using CRISPR/Cas9, especially in multiplex gene editing. Our system achieved at least 80% efficiency for 1-8 kb gene deletions, at least 90% efficiency for 1-2 kb gene insertions, near 100% efficiency for site-directed mutagenesis, 23.6% efficiency for large DNA fragment deletion and near 50% efficiency for three simultaneous point mutations. The efficiency for multiplex gene editing was further improved by regulating the nick repair mechanism mediated by ligD gene, which finally led to roughly 65% efficiency for introducing three point mutations on the chromosome. To demonstrate its potential, we applied our system to simultaneously fine-tune three genes in the riboflavin operon and significantly improved the production of riboflavin in a single cycle. CONCLUSIONS We present not only the iterative CRISPR/Cas9n system for B. subtilis but also the highest efficiency for simultaneous modulation of multiple genes on the chromosome in B. subtilis reported to date. We anticipate this CRISPR/Cas9n mediated system to greatly enhance the optimization of diverse biological systems via metabolic engineering and synthetic biology.
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Affiliation(s)
- Dingyu Liu
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 China
| | - Can Huang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 China
| | - Jiaxin Guo
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 China
| | - Peiji Zhang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 China
| | - Tao Chen
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 China
| | - Zhiwen Wang
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 China
| | - Xueming Zhao
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072 China
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Sawyer EB, Grabowska AD, Cortes T. Translational regulation in mycobacteria and its implications for pathogenicity. Nucleic Acids Res 2019; 46:6950-6961. [PMID: 29947784 PMCID: PMC6101614 DOI: 10.1093/nar/gky574] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 06/14/2018] [Indexed: 01/13/2023] Open
Abstract
Protein synthesis is a fundamental requirement of all cells for survival and replication. To date, vast numbers of genetic and biochemical studies have been performed to address the mechanisms of translation and its regulation in Escherichia coli, but only a limited number of studies have investigated these processes in other bacteria, particularly in slow growing bacteria like Mycobacterium tuberculosis, the causative agent of human tuberculosis. In this Review, we highlight important differences in the translational machinery of M. tuberculosis compared with E. coli, specifically the presence of two additional proteins and subunit stabilizing elements such as the B9 bridge. We also consider the role of leaderless translation in the ability of M. tuberculosis to establish latent infection and look at the experimental evidence that translational regulatory mechanisms operate in mycobacteria during stress adaptation, particularly focussing on differences in toxin-antitoxin systems between E. coli and M. tuberculosis and on the role of tuneable translational fidelity in conferring phenotypic antibiotic resistance. Finally, we consider the implications of these differences in the context of the biological adaptation of M. tuberculosis and discuss how these regulatory mechanisms could aid in the development of novel therapeutics for tuberculosis.
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Affiliation(s)
- Elizabeth B Sawyer
- Pathogen Molecular Biology Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.,TB Centre, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Anna D Grabowska
- Pathogen Molecular Biology Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.,TB Centre, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Teresa Cortes
- Pathogen Molecular Biology Department, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.,TB Centre, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
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37
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Mauri M, Vecchione S, Fritz G. Deconvolution of Luminescence Cross-Talk in High-Throughput Gene Expression Profiling. ACS Synth Biol 2019; 8:1361-1370. [PMID: 31095908 DOI: 10.1021/acssynbio.9b00032] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Luciferase reporters have become standard genetic tools to monitor gene expression in real time and in high-throughput using microplate readers. Compared to reporter gene assays based on fluorescence proteins, luciferase reporters have a superior signal-to-noise ratio, since they do not suffer from the high autofluorescence background of the bacterial cell. However, at the same time luciferase reporters have the drawback of constant light emission, which leads to undesired cross-talk between neighboring wells on a microplate. To overcome this limitation, we developed a computational method to correct for luminescence bleed-through and to estimate the "true" luminescence activity for each well of a microplate. As the sole input our algorithm uses the signals measured from a calibration plate, in which the light emitted from a single luminescent well serves as an estimate for the "light-spread function". We show that this light-spread function can be used to deconvolve any other measurement obtained under the same technical conditions. Our analysis demonstrates that the correction preserves low-level signals close to the background and shows that it is universally applicable to different kinds of microplate readers and plate types.
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Affiliation(s)
- Marco Mauri
- LOEWE Center for Synthetic Microbiology and Department of Physics, Philipps-Universität Marburg, 35032 Marburg, Germany
| | - Stefano Vecchione
- LOEWE Center for Synthetic Microbiology and Department of Physics, Philipps-Universität Marburg, 35032 Marburg, Germany
| | - Georg Fritz
- LOEWE Center for Synthetic Microbiology and Department of Physics, Philipps-Universität Marburg, 35032 Marburg, Germany
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Li X, Xu S, Zhang X, Xu M, Yang T, Wang L, Zhang H, Fang H, Osire T, Yang S, Rao Z. Design of a high-efficiency synthetic system for l-asparaginase production in Bacillus subtilis. Eng Life Sci 2019; 19:229-239. [PMID: 32625005 DOI: 10.1002/elsc.201800166] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 12/07/2018] [Accepted: 01/17/2019] [Indexed: 12/28/2022] Open
Abstract
l-asparaginase has high application value in medicine and food industry, but the low yield limits its application. In this study, we designed a synthetic system in Bacillus subtilis to produce l-asparaginase by improving gene expression and optimizing the fermentation agitation speed. Gene expression was improved by respectively increasing transcription levels and translation speeds through screening promoters and RBS sequences. With the optimal promoter, P43, and the synthetic RBS sequence, the yield obtained in a shake flask was 371.87 U/mL, which was 2.09 times that with the original strain. To further enhance production in a 5-L fermenter, a multistage agitation speed control strategy was adopted, involving agitation at 600 rpm for the first 12 h, followed by a gradual increase in speed to 900 rpm, which resulted in the highest yield of l-asparaginase, 5321 U/mL, after 42 h of fermentation.
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Affiliation(s)
- Xu Li
- The Key Laboratory of Industrial Biotechnology Ministry of Education School of Biotechnology Jiangnan University Wuxi P. R. China
| | - Shuqin Xu
- The Key Laboratory of Industrial Biotechnology Ministry of Education School of Biotechnology Jiangnan University Wuxi P. R. China
| | - Xian Zhang
- The Key Laboratory of Industrial Biotechnology Ministry of Education School of Biotechnology Jiangnan University Wuxi P. R. China
| | - Meijuan Xu
- The Key Laboratory of Industrial Biotechnology Ministry of Education School of Biotechnology Jiangnan University Wuxi P. R. China
| | - Taowei Yang
- The Key Laboratory of Industrial Biotechnology Ministry of Education School of Biotechnology Jiangnan University Wuxi P. R. China
| | - Li Wang
- School of Food Science and Technology Jiangnan University Wuxi P. R. China
| | - Huiling Zhang
- School of Agriculture Ningxia University Yinchuan P. R. China
| | - Haitian Fang
- School of Agriculture Ningxia University Yinchuan P. R. China
| | - Tolbert Osire
- The Key Laboratory of Industrial Biotechnology Ministry of Education School of Biotechnology Jiangnan University Wuxi P. R. China
| | - Shangtian Yang
- Department of Chemical and Biomolecular Engineering The Ohio State University Columbus OH USA
| | - Zhiming Rao
- The Key Laboratory of Industrial Biotechnology Ministry of Education School of Biotechnology Jiangnan University Wuxi P. R. China
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Adalat R, Saleem F, Bashir A, Ahmad M, Zulfiqar S, Shakoori AR. Multiple upstream start codons (AUG) in 5' untranslated region enhance translation efficiency of cry2Ac11 without helper protein. J Cell Biochem 2019; 120:2236-2250. [PMID: 30242865 DOI: 10.1002/jcb.27534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 08/01/2018] [Indexed: 01/24/2023]
Abstract
Cry2Ac11, a 65 kDa insecticidal protein produced by Bacillus thuringiensis, shows toxicity against dipteran and lepidopteran larvae. It is encoded by cry2Ac11 gene ( orf3), which is part of an operon comprising orf1, orf2, and orf3. Orf2, a helper protein, helps in proper folding and prevents aberrant aggregation of newly produced molecules. In this study, we have elucidated the effect of different mutations in translation initiation region (TIR), particularly the ribosomal binding site and the start codon (RBS-ATG) on cry2Ac11 gene expression without helper protein. All recombinant constructs were expressed in acrystalliferous B. thuringiensis subsp israelensis 4Q7 under the control of strong chimeric promoter cyt1AP/STAB. Of all the mutants, mut/RBS2, with two consecutive AUGs after the spacer region in TIR, exhibited 89- and 2246-fold higher transcript levels compared with 4Q7-operSalI/RBS ( cry2Ac11 operon) and 4Q7-w-RBS ( cry2Ac11 gene), respectively. The analysis of mut/RBS2 messenger RNA (mRNA) structure in the RBS-AUG region showed the presence of RBS in the single-stranded part of the moderately stable hairpin loop. The high expression efficiency of Cry2Ac11 mutant without helper protein is a cumulative and cooperative result of chimeric promoter cyt1AP/STAB-SD with the optimal context of RBS-AUG region provided by multiple AUGs and stabilizer sequence at 3' ends.
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Affiliation(s)
- Rooma Adalat
- Department of Biotechnology, Lahore College for Women University, Lahore, Pakistan
| | - Faiza Saleem
- Department of Biotechnology, Lahore College for Women University, Lahore, Pakistan
| | - Aftab Bashir
- Department of Biological Sciences, Forman Christian College, Lahore, Pakistan
| | - Munir Ahmad
- School of Biological Sciences, Quaid-i-Azam Campus, University of the Punjab, Lahore, Pakistan
| | - Soumble Zulfiqar
- School of Biological Sciences, Quaid-i-Azam Campus, University of the Punjab, Lahore, Pakistan
| | - Abdul Rauf Shakoori
- School of Biological Sciences, Quaid-i-Azam Campus, University of the Punjab, Lahore, Pakistan.,Department of Biochemistry, Faculty of Life Sciences, University of Central Punjab, Lahore, Pakistan
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40
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Abstract
Genetic coding in bacteria largely operates via the "one gene-one protein" paradigm. However, the peculiarities of the mRNA structure, the versatility of the genetic code, and the dynamic nature of translation sometimes allow organisms to deviate from the standard rules of protein encoding. Bacteria can use several unorthodox modes of translation to express more than one protein from a single mRNA cistron. One such alternative path is the use of additional translation initiation sites within the gene. Proteins whose translation is initiated at different start sites within the same reading frame will differ in their N termini but will have identical C-terminal segments. On the other hand, alternative initiation of translation in a register different from the frame dictated by the primary start codon will yield a protein whose sequence is entirely different from the one encoded in the main frame. The use of internal mRNA codons as translation start sites is controlled by the nucleotide sequence and the mRNA folding. The proteins of the alternative proteome generated via the "genes-within-genes" strategy may carry important functions. In this review, we summarize the currently known examples of bacterial genes encoding more than one protein due to the utilization of additional translation start sites and discuss the known or proposed functions of the alternative polypeptides in relation to the main protein product of the gene. We also discuss recent proteome- and genome-wide approaches that will allow the discovery of novel translation initiation sites in a systematic fashion.
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41
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Sauer C, Ver Loren van Themaat E, Boender LGM, Groothuis D, Cruz R, Hamoen LW, Harwood CR, van Rij T. Exploring the Nonconserved Sequence Space of Synthetic Expression Modules in Bacillus subtilis. ACS Synth Biol 2018; 7:1773-1784. [PMID: 29939720 DOI: 10.1021/acssynbio.8b00110] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Increasing protein expression levels is a key step in the commercial production of enzymes. Predicting promoter activity and translation initiation efficiency based solely on consensus sequences have so far met with mixed results. Here, we addressed this challenge using a "brute-force" approach by designing and synthesizing a large combinatorial library comprising ∼12 000 unique synthetic expression modules (SEMs) for Bacillus subtilis. Using GFP fluorescence as a reporter of gene expression, we obtained a dynamic expression range that spanned 5 orders of magnitude, as well as a maximal 13-fold increase in expression compared with that of the already strong veg expression module. Analyses of the synthetic modules indicated that sequences at the 5'-end of the mRNA were the most important contributing factor to the differences in expression levels, presumably by preventing formation of strong secondary mRNA structures that affect translation initiation. When the gfp coding region was replaced by the coding region of the xynA gene, encoding the industrially relevant B. subtilis xylanase enzyme, only a 3-fold improvement in xylanase production was observed. Moreover, the correlation between GFP and xylanase expression levels was weak. This suggests that the differences in expression levels between the gfp and xynA constructs were due to differences in 5'-end mRNA folding and consequential differences in the rates of translation initiation. Our data show that the use of large libraries of SEMs, in combination with high-throughput technologies, is a powerful approach to improve the production of a specific protein, but that the outcome cannot necessarily be extrapolated to other proteins.
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Affiliation(s)
- Christopher Sauer
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
- DSM Biotechnology Center, P.O. Box 1, 2600 MA Delft, The Netherlands
| | | | | | - Daphne Groothuis
- DSM Biotechnology Center, P.O. Box 1, 2600 MA Delft, The Netherlands
| | - Rita Cruz
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
- DSM Biotechnology Center, P.O. Box 1, 2600 MA Delft, The Netherlands
| | - Leendert W. Hamoen
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
- Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Colin R. Harwood
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - Tjeerd van Rij
- DSM Biotechnology Center, P.O. Box 1, 2600 MA Delft, The Netherlands
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42
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Abstract
Codon usage depends on mutation bias, tRNA-mediated selection, and the need for high efficiency and accuracy in translation. One codon in a synonymous codon family is often strongly over-used, especially in highly expressed genes, which often leads to a high dN/dS ratio because dS is very small. Many different codon usage indices have been proposed to measure codon usage and codon adaptation. Sense codon could be misread by release factors and stop codons misread by tRNAs, which also contribute to codon usage in rare cases. This chapter outlines the conceptual framework on codon evolution, illustrates codon-specific and gene-specific codon usage indices, and presents their applications. A new index for codon adaptation that accounts for background mutation bias (Index of Translation Elongation) is presented and contrasted with codon adaptation index (CAI) which does not consider background mutation bias. They are used to re-analyze data from a recent paper claiming that translation elongation efficiency matters little in protein production. The reanalysis disproves the claim.
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43
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Schwenk S, Arnvig KB. Regulatory RNA in Mycobacterium tuberculosis, back to basics. Pathog Dis 2018; 76:4966984. [PMID: 29796669 PMCID: PMC7615687 DOI: 10.1093/femspd/fty035] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 04/09/2018] [Indexed: 01/17/2023] Open
Abstract
Since the turn of the millenium, RNA-based control of gene expression has added an extra dimension to the central dogma of molecular biology. Still, the roles of Mycobacterium tuberculosis regulatory RNAs and the proteins that facilitate their functions remain elusive, although there can be no doubt that RNA biology plays a central role in the baterium's adaptation to its many host environments. In this review, we have presented examples from model organisms and from M. tuberculosis to showcase the abundance and versatility of regulatory RNA, in order to emphasise the importance of these 'fine-tuners' of gene expression.
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MESH Headings
- Aconitate Hydratase/genetics
- Aconitate Hydratase/metabolism
- Bacterial Proteins/genetics
- Bacterial Proteins/metabolism
- Gene Expression Regulation, Bacterial
- Host-Pathogen Interactions
- Humans
- Mycobacterium tuberculosis/genetics
- Mycobacterium tuberculosis/metabolism
- Mycobacterium tuberculosis/pathogenicity
- Nucleic Acid Conformation
- RNA Stability
- RNA, Bacterial/genetics
- RNA, Bacterial/metabolism
- RNA, Small Cytoplasmic/genetics
- RNA, Small Cytoplasmic/metabolism
- RNA, Small Nuclear/genetics
- RNA, Small Nuclear/metabolism
- RNA, Small Untranslated/genetics
- RNA, Small Untranslated/metabolism
- Regulatory Sequences, Ribonucleic Acid
- Riboswitch
- Tuberculosis/microbiology
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Affiliation(s)
- Stefan Schwenk
- Institute for Structural and Molecular Biology, University College London, London WC1E 6BT, UK
| | - Kristine B Arnvig
- Institute for Structural and Molecular Biology, University College London, London WC1E 6BT, UK
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44
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Mearls EB, Jackter J, Colquhoun JM, Farmer V, Matthews AJ, Murphy LS, Fenton C, Camp AH. Transcription and translation of the sigG gene is tuned for proper execution of the switch from early to late gene expression in the developing Bacillus subtilis spore. PLoS Genet 2018; 14:e1007350. [PMID: 29702640 PMCID: PMC5942855 DOI: 10.1371/journal.pgen.1007350] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 05/09/2018] [Accepted: 04/03/2018] [Indexed: 12/01/2022] Open
Abstract
A cascade of alternative sigma factors directs developmental gene expression during spore formation by the bacterium Bacillus subtilis. As the spore develops, a tightly regulated switch occurs in which the early-acting sigma factor σF is replaced by the late-acting sigma factor σG. The gene encoding σG (sigG) is transcribed by σF and by σG itself in an autoregulatory loop; yet σG activity is not detected until σF-dependent gene expression is complete. This separation in σF and σG activities has been suggested to be due at least in part to a poorly understood intercellular checkpoint pathway that delays sigG expression by σF. Here we report the results of a careful examination of sigG expression during sporulation. Unexpectedly, our findings argue against the existence of a regulatory mechanism to delay sigG transcription by σF and instead support a model in which sigG is transcribed by σF with normal timing, but at levels that are very low. This low-level expression of sigG is the consequence of several intrinsic features of the sigG regulatory and coding sequence—promoter spacing, secondary structure potential of the mRNA, and start codon identity—that dampen its transcription and translation. Especially notable is the presence of a conserved hairpin in the 5’ leader sequence of the sigG mRNA that occludes the ribosome-binding site, reducing translation by up to 4-fold. Finally, we demonstrate that misexpression of sigG from regulatory and coding sequences lacking these features triggers premature σG activity in the forespore during sporulation, as well as inappropriate σG activity during vegetative growth. Altogether, these data indicate that transcription and translation of the sigG gene is tuned to prevent vegetative expression of σG and to ensure the precise timing of the switch from σF to σG in the developing spore. Global changes in gene expression occur during normal cellular growth and development, as well as during cancer cell transformation and bacterial pathogenesis. In this study we have investigated the molecular mechanisms that drive the switch from early to late developmental gene expression during spore formation by the model bacterium Bacillus subtilis. At early times, gene expression in the developing spore is directed by the transcription factor σF; at later times σF is replaced by σG. An important, yet poorly understood aspect of this σF-to-σG transition is how σG activation is delayed until the early, σF-directed phase of gene expression is complete. Here we have carefully examined expression of the gene encoding σG, sigG, and found that its transcription and translation are ordinarily dampened by several features of its regulatory and coding sequences. Moreover, we have found that this “tuning” of sigG expression is required for proper timing of the switch to σG. These results reframe our understanding of how sigG is regulated during B. subtilis sporulation and, more broadly, advance our understanding of how global changes in gene expression can be precisely executed at the molecular/genetic level.
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MESH Headings
- Bacillus subtilis/genetics
- Bacillus subtilis/physiology
- Bacterial Proteins/biosynthesis
- Bacterial Proteins/genetics
- Gene Expression Regulation, Bacterial
- Genes, Bacterial
- Inverted Repeat Sequences
- Models, Genetic
- Nucleic Acid Conformation
- Promoter Regions, Genetic
- Protein Biosynthesis
- RNA, Bacterial/chemistry
- RNA, Bacterial/genetics
- RNA, Bacterial/metabolism
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Sigma Factor/biosynthesis
- Sigma Factor/genetics
- Signal Transduction
- Spores, Bacterial/genetics
- Spores, Bacterial/physiology
- Transcription, Genetic
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Affiliation(s)
- Elizabeth B. Mearls
- Department of Biological Sciences, Mount Holyoke College, South Hadley, MA, USA
| | - Jacquelin Jackter
- Department of Biological Sciences, Mount Holyoke College, South Hadley, MA, USA
| | | | - Veronica Farmer
- Department of Biological Sciences, Mount Holyoke College, South Hadley, MA, USA
| | - Allison J. Matthews
- Department of Biological Sciences, Mount Holyoke College, South Hadley, MA, USA
| | - Laura S. Murphy
- Department of Biological Sciences, Mount Holyoke College, South Hadley, MA, USA
| | - Colleen Fenton
- Department of Biological Sciences, Mount Holyoke College, South Hadley, MA, USA
| | - Amy H. Camp
- Department of Biological Sciences, Mount Holyoke College, South Hadley, MA, USA
- * E-mail:
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Avilan L, Roumezi B, Risoul V, Bernard CS, Kpebe A, Belhadjhassine M, Rousset M, Brugna M, Latifi A. Phototrophic hydrogen production from a clostridial [FeFe] hydrogenase expressed in the heterocysts of the cyanobacterium Nostoc PCC 7120. Appl Microbiol Biotechnol 2018; 102:5775-5783. [DOI: 10.1007/s00253-018-8989-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 03/11/2018] [Accepted: 04/05/2018] [Indexed: 12/28/2022]
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46
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Haggett L, Bhasin A, Srivastava P, Fujita M. A revised model for the control of fatty acid synthesis by master regulator Spo0A in
Bacillus subtilis. Mol Microbiol 2018; 108:424-442. [DOI: 10.1111/mmi.13945] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/26/2018] [Indexed: 12/15/2022]
Affiliation(s)
- Lindsey Haggett
- Department of Biology and BiochemistryUniversity of HoustonHouston TX 77204‐5001 USA
| | - Archna Bhasin
- Department of Biology and BiochemistryUniversity of HoustonHouston TX 77204‐5001 USA
| | - Priyanka Srivastava
- Department of Biology and BiochemistryUniversity of HoustonHouston TX 77204‐5001 USA
| | - Masaya Fujita
- Department of Biology and BiochemistryUniversity of HoustonHouston TX 77204‐5001 USA
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A novel riboregulator switch system of gene expression for enhanced microbial production of succinic acid. J Ind Microbiol Biotechnol 2018; 45:253-269. [PMID: 29399712 DOI: 10.1007/s10295-018-2019-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 01/29/2018] [Indexed: 12/21/2022]
Abstract
In this paper, a novel riboregulator Switch System of Gene Expression including an OFF-TO-ON switch and an ON-TO-OFF switch was designed to regulate the expression state of target genes between "ON" and "OFF" by switching the identifiability of ribosome recognition site (RBS) based on the thermodynamic stability of different RNA-RNA hybridizations between RBS and small noncoding RNAs. The proposed riboregulator switch system was employed for the fermentative production of succinic acid using an engineered strain of E. coli JW1021, during which the expression of mgtC gene was controlled at "ON" state and that of pepc and ecaA genes were controlled at the "OFF" state in the lag phase and switched to the "OFF" and "ON" state once the strain enters the logarithmic phase. The results showed that using the strain of JW1021, the yield and productivity of succinic acid can reach 0.91 g g-1 and 3.25 g L-1 h-1, respectively, much higher than those using the strains without harboring the riboregulator switch system.
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48
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RNAseq analysis of α-proteobacterium Gluconobacter oxydans 621H. BMC Genomics 2018; 19:24. [PMID: 29304737 PMCID: PMC5756330 DOI: 10.1186/s12864-017-4415-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Accepted: 12/22/2017] [Indexed: 01/05/2023] Open
Abstract
Background The acetic acid bacterium Gluconobacter oxydans 621H is characterized by its exceptional ability to incompletely oxidize a great variety of carbohydrates in the periplasm. The metabolism of this α-proteobacterium has been characterized to some extent, yet little is known about its transcriptomes and related data. In this study, we applied two different RNAseq approaches. Primary transcriptomes enriched for 5′-ends of transcripts were sequenced to detect transcription start sites, which allow subsequent analysis of promoter motifs, ribosome binding sites, and 5´-UTRs. Whole transcriptomes were sequenced to identify expressed genes and operon structures. Results Sequencing of primary transcriptomes of G. oxydans revealed 2449 TSSs, which were classified according to their genomic context followed by identification of promoter and ribosome binding site motifs, analysis of 5´-UTRs including validation of predicted cis-regulatory elements and correction of start codons. 1144 (41%) of all genes were found to be expressed monocistronically, whereas 1634 genes were organized in 571 operons. Together, TSSs and whole transcriptome data were also used to identify novel intergenic (18), intragenic (328), and antisense transcripts (313). Conclusions This study provides deep insights into the transcriptional landscapes of G. oxydans. The comprehensive transcriptome data, which we made publicly available, facilitate further analysis of promoters and other regulatory elements. This will support future approaches for rational strain development and targeted gene expression in G. oxydans. The corrections of start codons further improve the high quality genome reference and support future proteome analysis. Electronic supplementary material The online version of this article (10.1186/s12864-017-4415-x) contains supplementary material, which is available to authorized users.
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Xu Y, Xu C, Li X, Sun B, Eldin AA, Jia Y. A combinational optimization method for efficient synthesis of tetramethylpyrazine by the recombinant Escherichia coli. Biochem Eng J 2018. [DOI: 10.1016/j.bej.2017.10.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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SwrD (YlzI) Promotes Swarming in Bacillus subtilis by Increasing Power to Flagellar Motors. J Bacteriol 2017; 200:JB.00529-17. [PMID: 29061663 DOI: 10.1128/jb.00529-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 09/29/2017] [Indexed: 11/20/2022] Open
Abstract
The bacterium Bacillus subtilis is capable of two kinds of flagellum-mediated motility: swimming, which occurs in liquid, and swarming, which occurs on a surface. Swarming is distinct from swimming in that it requires secretion of a surfactant, an increase in flagellar density, and perhaps additional factors. Here we report a new gene, swrD, located within the 32 gene fla-che operon dedicated to flagellar biosynthesis and chemotaxis, which when mutated abolished swarming motility. SwrD was not required for surfactant production, flagellar gene expression, or an increase in flagellar number. Instead, SwrD was required to increase flagellar power. Mutation of swrD reduced swimming speed and torque of tethered flagella, and all swrD-related phenotypes were restored when the stator subunits MotA and MotB were overexpressed either by spontaneous suppressor mutations or by artificial induction. We conclude that swarming motility requires flagellar power in excess of that which is needed to swim.IMPORTANCE Bacteria swim in liquid and swarm over surfaces by rotating flagella, but the difference between swimming and swarming is poorly understood. Here we report that SwrD of Bacillus subtilis is necessary for swarming because it increases flagellar torque and cells mutated for swrD swim with reduced speed. How flagellar motors generate power is primarily studied in Escherichia coli, and SwrD likely increases power in other organisms, like the Firmicutes, Clostridia, Spirochaetes, and the Deltaproteobacteria.
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