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Naeem FM, Gemler BT, McNutt ZA, Bundschuh R, Fredrick K. Analysis of programmed frameshifting during translation of prfB in Flavobacterium johnsoniae. RNA (NEW YORK, N.Y.) 2024; 30:136-148. [PMID: 37949662 PMCID: PMC10798248 DOI: 10.1261/rna.079721.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 10/27/2023] [Indexed: 11/12/2023]
Abstract
Ribosomes of Bacteroidia fail to recognize Shine-Dalgarno (SD) sequences due to sequestration of the 3' tail of the 16S rRNA on the 30S platform. Yet in these organisms, the prfB gene typically contains the programmed +1 frameshift site with its characteristic SD sequence. Here, we investigate prfB autoregulation in Flavobacterium johnsoniae, a member of the Bacteroidia. We find that the efficiency of prfB frameshifting in F. johnsoniae is low (∼7%) relative to that in Escherichia coli (∼50%). Mutation or truncation of bS21 in F. johnsoniae increases frameshifting substantially, suggesting that anti-SD (ASD) sequestration is responsible for the reduced efficiency. The frameshift site of certain Flavobacteriales, such as Winogradskyella psychrotolerans, has no SD. In F. johnsoniae, this W. psychrotolerans sequence supports frameshifting as well as the native sequence, and mutation of bS21 causes no enhancement. These data suggest that prfB frameshifting normally occurs without SD-ASD pairing, at least under optimal laboratory growth conditions. Chromosomal mutations that remove the frameshift or ablate the SD confer subtle growth defects in the presence of paraquat or streptomycin, respectively, indicating that both the autoregulatory mechanism and the SD element contribute to F. johnsoniae cell fitness. Analysis of prfB frameshift sites across 2686 representative bacteria shows loss of the SD sequence in many clades, with no obvious relationship to genome-wide SD usage. These data reveal unexpected variation in the mechanism of frameshifting and identify another group of organisms, the Verrucomicrobiales, that globally lack SD sequences.
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Affiliation(s)
- Fawwaz M Naeem
- Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Bryan T Gemler
- Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
- Interdisciplinary Biophysics Graduate Program, The Ohio State University, Columbus, Ohio 43210, USA
| | - Zakkary A McNutt
- Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
| | - Ralf Bundschuh
- Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
- Interdisciplinary Biophysics Graduate Program, The Ohio State University, Columbus, Ohio 43210, USA
- Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, USA
- Division of Hematology, Department of Internal Medicine, The Ohio State University, Columbus, Ohio 43210, USA
| | - Kurt Fredrick
- Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, Ohio 43210, USA
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, USA
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2
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Estrada K, Garciarrubio A, Merino E. Unraveling the plasticity of translation initiation in prokaryotes: Beyond the invariant Shine-Dalgarno sequence. PLoS One 2024; 19:e0289914. [PMID: 38206950 PMCID: PMC10783764 DOI: 10.1371/journal.pone.0289914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 07/28/2023] [Indexed: 01/13/2024] Open
Abstract
Translation initiation in prokaryotes is mainly defined, although not exclusively, by the interaction between the anti-Shine-Dalgarno sequence (antiSD), located at the 3'-terminus of the 16S ribosomal RNA, and a complementary sequence, the ribosome binding site, or Shine-Dalgarno (SD), located upstream of the start codon in prokaryotic mRNAs. The antiSD has a conserved 5'-CCUCC-3' core, but inter-species variations have been found regarding the participation of flanking bases in binding. These variations have been described for certain bacteria and, to a lesser extent, for some archaea. To further analyze these variations, we conducted binding-energy prediction analyses on over 6,400 genomic sequences from both domains. We identified 15 groups of antiSD variants that could be associated with the organisms' phylogenetic origin. Additionally, our findings revealed that certain organisms exhibit variations in the core itself. Importantly, an unaltered core is not necessarily required for the interaction between the 3'-terminus of the rRNA and the region preceding the AUG of the mRNA. In our study, we classified organisms into four distinct categories: i) those possessing a conserved core and demonstrating binding; ii) those with a conserved core but lacking evidence of binding; iii) those exhibiting binding in the absence of a conserved core; and iv) those lacking both a conserved core and evidence of binding. Our results demonstrate the flexibility of organisms in evolving different sequences involved in translation initiation beyond the traditional Shine-Dalgarno sequence. These findings are discussed in terms of the evolution of translation initiation in prokaryotic organisms.
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Affiliation(s)
- Karel Estrada
- Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos (UAEM), Cuernavaca, Morelos, México
- Massive Sequencing and Bioinformatics Unit, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Alejandro Garciarrubio
- Department of Cell Engineering and Biocatalysis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Enrique Merino
- Department of Molecular Microbiology, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
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Irshad IU, Sharma AK. Decoding stoichiometric protein synthesis in E. coli through translation rate parameters. BIOPHYSICAL REPORTS 2023; 3:100131. [PMID: 37789867 PMCID: PMC10542608 DOI: 10.1016/j.bpr.2023.100131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 09/11/2023] [Indexed: 10/05/2023]
Abstract
E. coli is one of the most widely used organisms for understanding the principles of cellular and molecular genetics. However, we are yet to understand the origin of several experimental observations related to the regulation of gene expression in E. coli. One of the prominent examples in this context is the proportional synthesis in multiprotein complexes where all of their obligate subunits are produced in proportion to their stoichiometry. In this work, by combining the next-generation sequencing data with the stochastic simulations of protein synthesis, we explain the origin of proportional protein synthesis in multicomponent complexes. We find that the estimated initiation rates for the translation of all subunits in those complexes are proportional to their stoichiometry. This constraint on protein synthesis kinetics enforces proportional protein synthesis without requiring any feedback mechanism. We also find that the translation initiation rates in E. coli are influenced by the coding sequence length and the enrichment of A and C nucleotides near the start codon. Thus, this study rationalizes the role of conserved and nonrandom features of genes in regulating the translation kinetics and unravels a key principle of the regulation of protein synthesis.
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Affiliation(s)
| | - Ajeet K. Sharma
- Department of Physics, Indian Institute of Technology Jammu, Jammu, India
- Department of Biosciences and Bioengineering, Indian Institute of Technology Jammu, Jammu, India
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4
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Bryant OJ, Lastovka F, Powell J, Chung BYW. The distinct translational landscapes of gram-negative Salmonella and gram-positive Listeria. Nat Commun 2023; 14:8167. [PMID: 38071303 PMCID: PMC10710512 DOI: 10.1038/s41467-023-43759-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Accepted: 11/17/2023] [Indexed: 12/18/2023] Open
Abstract
Translational control in pathogenic bacteria is fundamental to gene expression and affects virulence and other infection phenotypes. We used an enhanced ribosome profiling protocol coupled with parallel transcriptomics to capture accurately the global translatome of two evolutionarily distant pathogenic bacteria-the Gram-negative bacterium Salmonella and the Gram-positive bacterium Listeria. We find that the two bacteria use different mechanisms to translationally regulate protein synthesis. In Salmonella, in addition to the expected correlation between translational efficiency and cis-regulatory features such as Shine-Dalgarno (SD) strength and RNA secondary structure around the initiation codon, our data reveal an effect of the 2nd and 3rd codons, where the presence of tandem lysine codons (AAA-AAA) enhances translation in both Salmonella and E. coli. Strikingly, none of these features are seen in efficiently translated Listeria transcripts. Instead, approximately 20% of efficiently translated Listeria genes exhibit 70 S footprints seven nt upstream of the authentic start codon, suggesting that these genes may be subject to a novel translational initiation mechanism. Our results show that SD strength is not a direct hallmark of translational efficiency in all bacteria. Instead, Listeria has evolved additional mechanisms to control gene expression level that are distinct from those utilised by Salmonella and E. coli.
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Affiliation(s)
- Owain J Bryant
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
- Centre for Structural Biology, National Cancer Institute, 21702, Frederick, MD, USA
| | - Filip Lastovka
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Jessica Powell
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Betty Y-W Chung
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK.
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5
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Weber M, Sogues A, Yus E, Burgos R, Gallo C, Martínez S, Lluch‐Senar M, Serrano L. Comprehensive quantitative modeling of translation efficiency in a genome-reduced bacterium. Mol Syst Biol 2023; 19:e11301. [PMID: 37642167 PMCID: PMC10568206 DOI: 10.15252/msb.202211301] [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: 08/16/2022] [Revised: 07/17/2023] [Accepted: 07/24/2023] [Indexed: 08/31/2023] Open
Abstract
Translation efficiency has been mainly studied by ribosome profiling, which only provides an incomplete picture of translation kinetics. Here, we integrated the absolute quantifications of tRNAs, mRNAs, RNA half-lives, proteins, and protein half-lives with ribosome densities and derived the initiation and elongation rates for 475 genes (67% of all genes), 73 with high precision, in the bacterium Mycoplasma pneumoniae (Mpn). We found that, although the initiation rate varied over 160-fold among genes, most of the known factors had little impact on translation efficiency. Local codon elongation rates could not be fully explained by the adaptation to tRNA abundances, which varied over 100-fold among tRNA isoacceptors. We provide a comprehensive quantitative view of translation efficiency, which suggests the existence of unidentified mechanisms of translational regulation in Mpn.
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Affiliation(s)
- Marc Weber
- Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Adrià Sogues
- Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Eva Yus
- Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Raul Burgos
- Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Carolina Gallo
- Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Sira Martínez
- Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Maria Lluch‐Senar
- Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Luis Serrano
- Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu Fabra (UPF)BarcelonaSpain
- ICREABarcelonaSpain
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6
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Xu Q, Du Q, Gao J, Chen L, Dong X, Li J. A robust genetic toolbox for fine-tuning gene expression in the CO 2-Fixing methanogenic archaeon Methanococcus maripaludis. Metab Eng 2023; 79:130-145. [PMID: 37495072 DOI: 10.1016/j.ymben.2023.07.007] [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: 05/16/2023] [Revised: 07/12/2023] [Accepted: 07/23/2023] [Indexed: 07/28/2023]
Abstract
Libraries of well-characterized genetic elements for fine-tuning gene expression are essential for biological and biotechnological research and applications. The fast-growing and genetically tractable methanogen, Methanococcus maripaludis, is a promising host organism for biotechnological conversion of carbon dioxide and renewable hydrogen into fuels and value-added products, as well as fundamental biological studies of archaea. However, the lack of molecular tools for gene expression has hindered its application as a workhorse to fine-tune gene and metabolic pathway expressions. In this study, we developed a genetic toolbox, including libraries of promoters, ribosome binding sites (RBS), and neutral sites for chromosomal integration, to facilitate precise gene expression in M. maripaludis. We generated a promoter library consisting of 81 constitutive promoters with expression strengths spanning a ∼104-fold dynamic range. Importantly, we identified a base composition rule for strong archaeal promoters and successfully remodeled weak promoters, enhancing their activities by up to 120-fold. We also established an RBS library containing 42 diverse RBS sequences with translation strengths covering a ∼100-fold dynamic range. Additionally, we identified eight neutral sites and developed a one-step, Cas9-based marker-less knock-in approach for chromosomal integration. We successfully applied the characterized promoter and RBS elements to significantly improve recombinant protein expression by 41-fold and modulate essential gene expression to generate corresponding physiological changes in M. maripaludis. Therefore, this work establishes a solid foundation for utilizing this autotrophic methanogen as an ideal workhorse for archaeal biology and biotechnological studies and applications.
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Affiliation(s)
- Qing Xu
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072, China; State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Qing Du
- Key Laboratory of Development and Application of Rural Renewable Energy, Biogas Institute of Ministry of Agriculture and Rural Affairs, Chengdu, 610041, China
| | - Jian Gao
- School of Basic Medical Sciences and School of Biomedical Engineering, Hubei University of Medicine, Shiyan, China
| | - Lei Chen
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072, China
| | - Xiuzhu Dong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, No.19A Yuquan Road, Shijingshan District, Beijing, 100049, China
| | - Jie Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, No.19A Yuquan Road, Shijingshan District, Beijing, 100049, China.
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7
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Ghosh A, Bharmal MHM, Ghaleb AM, Nandana V, Schrader JM. Initiator AUGs Are Discriminated from Elongator AUGs Predominantly through mRNA Accessibility in C. crescentus. J Bacteriol 2023; 205:e0042022. [PMID: 37092987 PMCID: PMC10210977 DOI: 10.1128/jb.00420-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Accepted: 03/27/2023] [Indexed: 04/25/2023] Open
Abstract
The initiation of translation in bacteria is thought to occur upon base pairing between the Shine-Dalgarno (SD) site in the mRNA and the anti-SD site in the rRNA. However, in many bacterial species, such as Caulobacter crescentus, a minority of mRNAs have SD sites. To examine the functional importance of SD sites in C. crescentus, we analyzed the transcriptome and found that more SD sites exist in the coding sequence than in the preceding start codons. To examine the function of SD sites in initiation, we designed a series of mutants with altered ribosome accessibility and SD content in translation initiation regions (TIRs) and in elongator AUG regions (EARs). A lack of mRNA structure content is required for initiation in TIRs, and, when introduced into EARs, can stimulate initiation, thereby suggesting that low mRNA structure content is a major feature that is required for initiation. SD sites appear to stimulate initiation in TIRs, which generally lack structure content, but SD sites only stimulate initiation in EARs if RNA secondary structures are destabilized. Taken together, these results suggest that the difference in secondary structure between TIRs and EARs directs ribosomes to start codons where SD base pairing can tune the efficiency of initiation, but SDs in EARs do not stimulate initiation, as they are blocked by stable secondary structures. This highlights the importance of studying translation initiation mechanisms in diverse bacterial species. IMPORTANCE Start codon selection is an essential process that is thought to occur via the base pairing of the rRNA to the SD site in the mRNA. This model is based on studies in E. coli, yet whole-genome sequencing revealed that SD sites are absent at start codons in many species. By examining the transcriptome of C. crescentus, we found more SD-AUG pairs in the CDS of mRNAs than preceding start codons, yet these internal sites do not initiate. Instead, start codon regions have lower mRNA secondary structure content than do internal SD-AUG regions. Therefore, we find that start codon selection is not controlled by the presence of SD sites, which tune initiation efficiency, but by lower mRNA structure content surrounding the start codon.
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Affiliation(s)
- Aishwarya Ghosh
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | | | - Amar M. Ghaleb
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Vidhyadhar Nandana
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Jared M. Schrader
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
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8
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McNutt ZA, Roy B, Gemler BT, Shatoff EA, Moon KM, Foster LJ, Bundschuh R, Fredrick K. Ribosomes lacking bS21 gain function to regulate protein synthesis in Flavobacterium johnsoniae. Nucleic Acids Res 2023; 51:1927-1942. [PMID: 36727479 PMCID: PMC9976891 DOI: 10.1093/nar/gkad047] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/12/2023] [Accepted: 01/16/2023] [Indexed: 02/03/2023] Open
Abstract
Ribosomes of Bacteroidia (formerly Bacteroidetes) fail to recognize Shine-Dalgarno (SD) sequences even though they harbor the anti-SD (ASD) of 16S rRNA. Inhibition of SD-ASD pairing is due to sequestration of the 3' tail of 16S rRNA in a pocket formed by bS21, bS18, and bS6 on the 30S platform. Interestingly, in many Flavobacteriales, the gene encoding bS21, rpsU, contains an extended SD sequence. In this work, we present genetic and biochemical evidence that bS21 synthesis in Flavobacterium johnsoniae is autoregulated via a subpopulation of ribosomes that specifically lack bS21. Mutation or depletion of bS21 in the cell increases translation of reporters with strong SD sequences, such as rpsU'-gfp, but has no effect on other reporters. Purified ribosomes lacking bS21 (or its C-terminal region) exhibit higher rates of initiation on rpsU mRNA and lower rates of initiation on other (SD-less) mRNAs than control ribosomes. The mechanism of autoregulation depends on extensive pairing between mRNA and 16S rRNA, and exceptionally strong SD sequences, with predicted pairing free energies of < -13 kcal/mol, are characteristic of rpsU across the Bacteroidota. This work uncovers a clear example of specialized ribosomes in bacteria.
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Affiliation(s)
- Zakkary A McNutt
- Ohio State Biochemistry Program, 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
| | - Bryan T Gemler
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.,Interdisciplinary Biophysics Graduate 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
| | - Kyung-Mee Moon
- Department of Biochemistry and Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, V3T1Z4, Canada
| | - Leonard J Foster
- Department of Biochemistry and Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, V3T1Z4, Canada
| | - Ralf Bundschuh
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.,Interdisciplinary Biophysics Graduate Program, The Ohio State University, Columbus, OH 43210, USA.,Department of Physics, The Ohio State University, Columbus, OH 43210, USA.,Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH 43210, USA.,Division of Hematology, Department of Internal Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Kurt Fredrick
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA.,Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA.,Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
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9
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Qi L, Liu H, Gao J, Deng K, Wang X, Dong X, Li J. Endonucleolytic processing plays a critical role in the maturation of ribosomal RNA in Methanococcus maripaludis. RNA Biol 2023; 20:760-773. [PMID: 37731260 PMCID: PMC10515664 DOI: 10.1080/15476286.2023.2258035] [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] [Accepted: 09/06/2023] [Indexed: 09/22/2023] Open
Abstract
Ribosomal RNA (rRNA) processing and maturation are fundamentally important for ribosome biogenesis, but the mechanisms in archaea, the third form of life, remains largely elusive. This study aimed to investigate the rRNA maturation process in Methanococcus maripaludis, a representative archaeon lacking known 3'-5' exonucleases. Through cleavage site identification and enzymatic assays, the splicing endonuclease EndA was determined to process the bulge-helix-bulge (BHB) motifs in 16S and 23S rRNA precursors. After splicing, the circular processing intermediates were formed and this was confirmed by quantitative RT-PCR and Northern blot. Ribonuclease assay revealed a specific cleavage at a 10-nt A/U-rich motif at the mature 5' end of pre-16S rRNA, which linearized circular pre-16S rRNA intermediate. Further 3'-RACE and ribonuclease assays determined that the endonuclease Nob1 cleaved the 3' extension of pre-16S rRNA, and so generated the mature 3' end. Circularized RT-PCR (cRT-PCR) and 5'-RACE identified two cleavage sites near helix 1 at the 5' end of 23S rRNA, indicating that an RNA structure-based endonucleolytic processing linearized the circular pre-23S rRNA intermediate. In the maturation of pre-5S rRNA, multiple endonucleolytic processing sites were determined at the 10-nt A/U-rich motif in the leader and trailer sequence. This study demonstrates that endonucleolytic processing, particularly at the 10-nt A/U-rich motifs play an essential role in the pre-rRNA maturation of M. maripaludis, indicating diverse pathways of rRNA maturation in archaeal species.
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Affiliation(s)
- Lei Qi
- School of Basic Medical Sciences and School of Biomedical Engineering, Hubei University of Medicine, Shiyan, China
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Huan Liu
- School of Basic Medical Sciences and School of Biomedical Engineering, Hubei University of Medicine, Shiyan, China
| | - Jian Gao
- School of Basic Medical Sciences and School of Biomedical Engineering, Hubei University of Medicine, Shiyan, China
| | - Kai Deng
- School of Basic Medical Sciences and School of Biomedical Engineering, Hubei University of Medicine, Shiyan, China
| | - Xiaoyan Wang
- School of Basic Medical Sciences and School of Biomedical Engineering, Hubei University of Medicine, Shiyan, China
| | - Xiuzhu Dong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Jie Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
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10
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Kohl MP, Kompatscher M, Clementi N, Holl L, Erlacher M. Initiation at AUGUG and GUGUG sequences can lead to translation of overlapping reading frames in E. coli. Nucleic Acids Res 2022; 51:271-289. [PMID: 36546769 PMCID: PMC9841429 DOI: 10.1093/nar/gkac1175] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 11/16/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022] Open
Abstract
During initiation, the ribosome is tasked to efficiently recognize open reading frames (ORFs) for accurate and fast translation of mRNAs. A critical step is start codon recognition, which is modulated by initiation factors, mRNA structure, a Shine Dalgarno (SD) sequence and the start codon itself. Within the Escherichia coli genome, we identified more than 50 annotated initiation sites harboring AUGUG or GUGUG sequence motifs that provide two canonical start codons, AUG and GUG, in immediate proximity. As these sites may challenge start codon recognition, we studied if and how the ribosome is accurately guided to the designated ORF, with a special focus on the SD sequence as well as adenine at the fourth coding sequence position (A4). By in vitro and in vivo experiments, we characterized key requirements for unambiguous start codon recognition, but also discovered initiation sites that lead to the translation of both overlapping reading frames. Our findings corroborate the existence of an ambiguous translation initiation mechanism, implicating a multitude of so far unrecognized ORFs and translation products in bacteria.
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Affiliation(s)
- Maximilian P Kohl
- Institute of Genomics and RNomics, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Maria Kompatscher
- Institute of Genomics and RNomics, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Nina Clementi
- Institute of Genomics and RNomics, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Lena Holl
- Institute of Genomics and RNomics, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Matthias D Erlacher
- To whom correspondence should be addressed. Tel: +43 512900370256; Fax: +43 512900373100;
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11
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Komarova ES, Dontsova OA, Pyshnyi DV, Kabilov MR, Sergiev PV. Flow-Seq Method: Features and Application in Bacterial Translation Studies. Acta Naturae 2022; 14:20-37. [PMID: 36694903 PMCID: PMC9844084 DOI: 10.32607/actanaturae.11820] [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: 10/04/2022] [Accepted: 11/11/2022] [Indexed: 01/22/2023] Open
Abstract
The Flow-seq method is based on using reporter construct libraries, where a certain element regulating the gene expression of fluorescent reporter proteins is represented in many thousands of variants. Reporter construct libraries are introduced into cells, sorted according to their fluorescence level, and then subjected to next-generation sequencing. Therefore, it turns out to be possible to identify patterns that determine the expression efficiency, based on tens and hundreds of thousands of reporter constructs in one experiment. This method has become common in evaluating the efficiency of protein synthesis simultaneously by multiple mRNA variants. However, its potential is not confined to this area. In the presented review, a comparative analysis of the Flow-seq method and other alternative approaches used for translation efficiency evaluation of mRNA was carried out; the features of its application and the results obtained by Flow-seq were also considered.
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Affiliation(s)
- E. S. Komarova
- Institute of Functional Genomics, Lomonosov Moscow State University, Moscow, 119234 Russia
| | - O. A. Dontsova
- Department of Chemistry, Lomonosov Moscow State University, Moscow, 119234 Russia
- Skolkovo Institute of Science and Technology, Moscow, 121205 Russia
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119234 Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117437 Russia
| | - D. V. Pyshnyi
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090 Russia
| | - M. R. Kabilov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090 Russia
| | - P. V. Sergiev
- Institute of Functional Genomics, Lomonosov Moscow State University, Moscow, 119234 Russia
- Department of Chemistry, Lomonosov Moscow State University, Moscow, 119234 Russia
- Skolkovo Institute of Science and Technology, Moscow, 121205 Russia
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119234 Russia
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12
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Wang Y, Luo Y, Huang Y. Schizosaccharomyces pombe
Sls1 is primarily required for
cox1
mRNA translation. Yeast 2022; 39:521-534. [DOI: 10.1002/yea.3813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 07/26/2022] [Accepted: 09/08/2022] [Indexed: 11/10/2022] Open
Affiliation(s)
- Yirong Wang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, School of Life SciencesNanjing Normal University1 Wenyuan RoadNanjing210023China
| | - Ying Luo
- Jiangsu Key Laboratory for Microbes and Functional Genomics, School of Life SciencesNanjing Normal University1 Wenyuan RoadNanjing210023China
| | - Ying Huang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, School of Life SciencesNanjing Normal University1 Wenyuan RoadNanjing210023China
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13
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Fages-Lartaud M, Tietze L, Elie F, Lale R, Hohmann-Marriott MF. mCherry contains a fluorescent protein isoform that interferes with its reporter function. Front Bioeng Biotechnol 2022; 10:892138. [PMID: 36017355 PMCID: PMC9395592 DOI: 10.3389/fbioe.2022.892138] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 06/30/2022] [Indexed: 11/13/2022] Open
Abstract
Fluorescent proteins are essential reporters in cell and molecular biology. Here, we found that red-fluorescent proteins possess an alternative translation initiation site that produces a short functional protein isoform in both prokaryotes and eukaryotes. The short isoform creates significant background fluorescence that biases the outcome of expression studies. In this study, we identified the short protein isoform, traced its origin, and determined the extent of the issue within the family of red fluorescent protein. Our analysis showed that the short isoform defect of the red fluorescent protein family may affect the interpretation of many published studies. We provided a re-engineered mCherry variant that lacks background expression as an improved tool for imaging and protein expression studies.
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Affiliation(s)
- Maxime Fages-Lartaud
- Department of Biotechnology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Lisa Tietze
- Department of Biotechnology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Florence Elie
- Department of Biotechnology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Rahmi Lale
- Department of Biotechnology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Martin Frank Hohmann-Marriott
- Department of Biotechnology, Norwegian University of Science and Technology, Trondheim, Norway
- United Scientists CORE (Limited), Dunedin, New Zealand
- *Correspondence: Martin Frank Hohmann-Marriott,
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14
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Ray S, Dandpat SS, Chatterjee S, Walter NG. Precise tuning of bacterial translation initiation by non-equilibrium 5'-UTR unfolding observed in single mRNAs. Nucleic Acids Res 2022; 50:8818-8833. [PMID: 35892287 PMCID: PMC9410914 DOI: 10.1093/nar/gkac635] [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: 12/16/2021] [Revised: 06/15/2022] [Accepted: 07/14/2022] [Indexed: 11/21/2022] Open
Abstract
Noncoding, structured 5′-untranslated regions (5′-UTRs) of bacterial messenger RNAs (mRNAs) can control translation efficiency by forming structures that either recruit or repel the ribosome. Here we exploit a 5′-UTR embedded preQ1-sensing, pseudoknotted translational riboswitch to probe how binding of a small ligand controls recruitment of the bacterial ribosome to the partially overlapping Shine-Dalgarno (SD) sequence. Combining single-molecule fluorescence microscopy with mutational analyses, we find that the stability of 30S ribosomal subunit binding is inversely correlated with the free energy needed to unfold the 5′-UTR during mRNA accommodation into the mRNA binding cleft. Ligand binding to the riboswitch stabilizes the structure to both antagonize 30S recruitment and accelerate 30S dissociation. Proximity of the 5′-UTR and stability of the SD:anti-SD interaction both play important roles in modulating the initial 30S-mRNA interaction. Finally, depletion of small ribosomal subunit protein S1, known to help resolve structured 5′-UTRs, further increases the energetic penalty for mRNA accommodation. The resulting model of rapid standby site exploration followed by gated non-equilibrium unfolding of the 5′-UTR during accommodation provides a mechanistic understanding of how translation efficiency is governed by riboswitches and other dynamic structure motifs embedded upstream of the translation initiation site of bacterial mRNAs.
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Affiliation(s)
- Sujay Ray
- Single-Molecule Analysis Group, Department of Chemistry and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Shiba S Dandpat
- Single-Molecule Analysis Group, Department of Chemistry and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Surajit Chatterjee
- Single-Molecule Analysis Group, Department of Chemistry and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Nils G Walter
- Single-Molecule Analysis Group, Department of Chemistry and Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI 48109, USA
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15
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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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16
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The Role of the Universally Conserved ATPase YchF/Ola1 in Translation Regulation during Cellular Stress. Microorganisms 2021; 10:microorganisms10010014. [PMID: 35056463 PMCID: PMC8779481 DOI: 10.3390/microorganisms10010014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 12/16/2021] [Accepted: 12/20/2021] [Indexed: 11/17/2022] Open
Abstract
The ability to respond to metabolic or environmental changes is an essential feature in all cells and involves both transcriptional and translational regulators that adjust the metabolic activity to fluctuating conditions. While transcriptional regulation has been studied in detail, the important role of the ribosome as an additional player in regulating gene expression is only beginning to emerge. Ribosome-interacting proteins are central to this translational regulation and include universally conserved ribosome interacting proteins, such as the ATPase YchF (Ola1 in eukaryotes). In both eukaryotes and bacteria, the cellular concentrations of YchF/Ola1 determine the ability to cope with different stress conditions and are linked to several pathologies in humans. The available data indicate that YchF/Ola1 regulates the stress response via controlling non-canonical translation initiation and via protein degradation. Although the molecular mechanisms appear to be different between bacteria and eukaryotes, increased non-canonical translation initiation is a common consequence of YchF/Ola1 regulated translational control in E. coli and H. sapiens. In this review, we summarize recent insights into the role of the universally conserved ATPase YchF/Ola1 in adapting translation to unfavourable conditions.
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17
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Lee HM, Ren J, Kim WY, Vo PNL, Eyun SI, Na D. Introduction of an AU-rich Element into the 5’ UTR of mRNAs Enhances Protein Expression in Escherichia coli by S1 Protein and Hfq Protein. BIOTECHNOL BIOPROC E 2021. [DOI: 10.1007/s12257-020-0348-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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18
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Bahiri Elitzur S, Cohen-Kupiec R, Yacobi D, Fine L, Apt B, Diament A, Tuller T. Prokaryotic rRNA-mRNA interactions are involved in all translation steps and shape bacterial transcripts. RNA Biol 2021; 18:684-698. [PMID: 34586043 DOI: 10.1080/15476286.2021.1978767] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
The well-established Shine-Dalgarno model suggests that translation initiation in bacteria is regulated via base-pairing between ribosomal RNA (rRNA) and mRNA. We used novel computational analyses and modelling of 823 bacterial genomes coupled with experiments to demonstrate that rRNA-mRNA interactions are diverse and regulate all translation steps from pre-initiation to termination. Previous research has reported the significant influence of rRNA-mRNA interactions, mainly in the initiation phase of translation. The results reported in this paper suggest that, in addition to the rRNA-mRNA interactions near the start codon that trigger initiation in bacteria, rRNA-mRNA interactions affect all sub-stages of the translation process (pre-initiation, initiation, elongation, termination). As these interactions dictate translation efficiency, they serve as an evolutionary driving force for shaping transcripts in bacteria while considering trade-offs between the effects of different interactions across different transcript regions on translation efficacy and efficiency. We observed selection for strong interactions in regions where such interactions are likely to enhance initiation, regulate early elongation, and ensure translation termination fidelity. We discovered selection against strong interactions and for intermediate interactions in coding regions and presented evidence that these patterns maximize elongation efficiency while also enhancing initiation. These finding are relevant to all biomedical disciplines due to the centrality of the translation process and the effect of rRNA-mRNA interactions on transcript evolution.
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Affiliation(s)
| | | | - Dana Yacobi
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Larissa Fine
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Boaz Apt
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Alon Diament
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Tamir Tuller
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel.,The Sagol School of Neuroscience, Tel-Aviv University, Tel Aviv, Israel
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19
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Migur A, Heyl F, Fuss J, Srikumar A, Huettel B, Steglich C, Prakash JSS, Reinhardt R, Backofen R, Owttrim GW, Hess WR. The temperature-regulated DEAD-box RNA helicase CrhR interactome: Autoregulation and photosynthesis-related transcripts. JOURNAL OF EXPERIMENTAL BOTANY 2021:erab416. [PMID: 34499142 DOI: 10.1093/jxb/erab416] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Indexed: 06/13/2023]
Abstract
RNA helicases play crucial functions in RNA biology. In plants, RNA helicases are encoded by large gene families, performing roles in abiotic stress responses, development, the post-transcriptional regulation of gene expression as well as house-keeping functions. Several of these RNA helicases are targeted to the organelles, mitochondria and chloroplasts. Cyanobacteria are the direct evolutionary ancestors of plant chloroplasts. The cyanobacterium Synechocystis 6803 encodes a single DEAD-box RNA helicase, CrhR, that is induced by a range of abiotic stresses, including low temperature. Though the ΔcrhR mutant exhibits a severe cold-sensitive phenotype, the physiological function(s) performed by CrhR have not been described. To identify transcripts interacting with CrhR, we performed RNA co-immunoprecipitation with extracts from a Synechocystis crhR deletion mutant expressing the FLAG-tagged native CrhR or a K57A mutated version with an anticipated enhanced RNA binding. The composition of the interactome was strikingly biased towards photosynthesis-associated and redox-controlled transcripts. A transcript highly enriched in all experiments was the crhR mRNA, suggesting an auto-regulatory molecular mechanism. The identified interactome explains the described physiological role of CrhR in response to the redox poise of the photosynthetic electron transport chain and characterizes CrhR as an enzyme with a diverse range of transcripts as molecular targets.
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Affiliation(s)
- Anzhela Migur
- Faculty of Biology, University of Freiburg, Schänzlestr., Freiburg, Germany
| | - Florian Heyl
- Department of Computer Science, University of Freiburg, Georges-Koehler-Allee, Freiburg, Germany
| | - Janina Fuss
- Max Planck-Genome-Centre Cologne, Carl-von-Linné-Weg, Köln, Germany
| | - Afshan Srikumar
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Bruno Huettel
- Max Planck-Genome-Centre Cologne, Carl-von-Linné-Weg, Köln, Germany
| | - Claudia Steglich
- Faculty of Biology, University of Freiburg, Schänzlestr., Freiburg, Germany
| | - Jogadhenu S S Prakash
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | | | - Rolf Backofen
- Department of Computer Science, University of Freiburg, Georges-Koehler-Allee, Freiburg, Germany
| | - George W Owttrim
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Wolfgang R Hess
- Faculty of Biology, University of Freiburg, Schänzlestr., Freiburg, Germany
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20
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How Does Bacillus thuringiensis Crystallize Such a Large Diversity of Toxins? Toxins (Basel) 2021; 13:toxins13070443. [PMID: 34206796 PMCID: PMC8309854 DOI: 10.3390/toxins13070443] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 06/22/2021] [Accepted: 06/24/2021] [Indexed: 12/31/2022] Open
Abstract
Bacillus thuringiensis (Bt) is a natural crystal-making bacterium. Bt diversified into many subspecies that have evolved to produce crystals of hundreds of pesticidal proteins with radically different structures. Their crystalline form ensures stability and controlled release of these major virulence factors. They are responsible for the toxicity and host specificity of Bt, explaining its worldwide use as a biological insecticide. Most research has been devoted to understanding the mechanisms of toxicity of these toxins while the features driving their crystallization have long remained elusive, essentially due to technical limitations. The evolution of methods in structural biology, pushing back the limits in size of amenable protein crystals now allows access to be gained to structural information hidden within natural crystals of such toxins. In this review, we present the main parameters that have been identified as key drivers of toxin crystallization in Bt, notably in the light of recent discoveries driven by structural biology studies. Then, we develop how the future evolution of structural biology will hopefully unveil new mechanisms of Bt toxin crystallization, opening the door to their hijacking with the aim of developing a versatile in vivo crystallization platform of high academic and industrial interest.
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21
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Riediger M, Spät P, Bilger R, Voigt K, Maček B, Hess WR. Analysis of a photosynthetic cyanobacterium rich in internal membrane systems via gradient profiling by sequencing (Grad-seq). THE PLANT CELL 2021; 33:248-269. [PMID: 33793824 PMCID: PMC8136920 DOI: 10.1093/plcell/koaa017] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 11/12/2020] [Indexed: 05/23/2023]
Abstract
Although regulatory small RNAs have been reported in photosynthetic cyanobacteria, the lack of clear RNA chaperones involved in their regulation poses a conundrum. Here, we analyzed the full complement of cellular RNAs and proteins using gradient profiling by sequencing (Grad-seq) in Synechocystis 6803. Complexes with overlapping subunits such as the CpcG1-type versus the CpcL-type phycobilisomes or the PsaK1 versus PsaK2 photosystem I pre(complexes) could be distinguished, supporting the high quality of this approach. Clustering of the in-gradient distribution profiles followed by several additional criteria yielded a short list of potential RNA chaperones that include an YlxR homolog and a cyanobacterial homolog of the KhpA/B complex. The data suggest previously undetected complexes between accessory proteins and CRISPR-Cas systems, such as a Csx1-Csm6 ribonucleolytic defense complex. Moreover, the exclusive association of either RpoZ or 6S RNA with the core RNA polymerase complex and the existence of a reservoir of inactive sigma-antisigma complexes is suggested. The Synechocystis Grad-seq resource is available online at https://sunshine.biologie.uni-freiburg.de/GradSeqExplorer/ providing a comprehensive resource for the functional assignment of RNA-protein complexes and multisubunit protein complexes in a photosynthetic organism.
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Affiliation(s)
- Matthias Riediger
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany
| | - Philipp Spät
- Department of Quantitative Proteomics, Interfaculty Institute for Cell Biology, University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - Raphael Bilger
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany
| | - Karsten Voigt
- IT Administration, Institute of Biology 3, Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany
| | - Boris Maček
- Department of Quantitative Proteomics, Interfaculty Institute for Cell Biology, University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - Wolfgang R Hess
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany
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22
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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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23
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Non-oral Prevotella stepping into the spotlight. Anaerobe 2021; 68:102321. [PMID: 33482304 DOI: 10.1016/j.anaerobe.2021.102321] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 01/12/2021] [Accepted: 01/14/2021] [Indexed: 02/07/2023]
Abstract
Species now affiliated to genus Prevotella have been known for decades as an integral part of human oral cavity microbiota. They were frequently isolated from patients with periodontitis or from dental root canals but also from healthy subjects. With the exception of Prevotella intermedia, they were considered opportunistic pathogens, as they were isolated also from various bacterial abscesses from the head, neck, breast, skin and various other body sites. Consequently, Prevotella were not in the focus of research activities. On the other hand, the four species found in the rumen never caused any disease and seemed early on to be numerous and important part of the rumen ecosystem indicating this genus harbored bacteria with enormously diverse habitats and lifestyles. The purpose of this review is to illustrate the main research themes performed in Prevotella on a path from less noted oral bacteria and from hard to cultivate and study rumen organisms to important mutualistic bacteria in guts of various mammals warranting major research efforts.
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24
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Meydan S, Klepacki D, Mankin AS, Vázquez-Laslop N. Identification of Translation Start Sites in Bacterial Genomes. Methods Mol Biol 2021; 2252:27-55. [PMID: 33765270 DOI: 10.1007/978-1-0716-1150-0_2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The knowledge of translation start sites is crucial for annotation of genes in bacterial genomes. However, systematic mapping of start codons in bacterial genes has mainly relied on predictions based on protein conservation and mRNA sequence features which, although useful, are not always accurate. We recently found that the pleuromutilin antibiotic retapamulin (RET) is a specific inhibitor of translation initiation that traps ribosomes specifically at start codons, and we used it in combination with ribosome profiling to map start codons in the Escherichia coli genome. This genome-wide strategy, that was named Ribo-RET, not only verifies the position of start codons in already annotated genes but also enables identification of previously unannotated open reading frames and reveals the presence of internal start sites within genes. Here, we provide a detailed Ribo-RET protocol for E. coli. Ribo-RET can be adapted for mapping the start codons of the protein-coding sequences in a variety of bacterial species.
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Affiliation(s)
- Sezen Meydan
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Dorota Klepacki
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Alexander S Mankin
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL, USA.
| | - Nora Vázquez-Laslop
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL, USA.
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25
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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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26
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Ryan D, Prezza G, Westermann AJ. An RNA-centric view on gut Bacteroidetes. Biol Chem 2020; 402:55-72. [PMID: 33544493 DOI: 10.1515/hsz-2020-0230] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/21/2020] [Indexed: 01/26/2023]
Abstract
Bacteria employ noncoding RNAs to maintain cellular physiology, adapt global gene expression to fluctuating environments, sense nutrients, coordinate their interaction with companion microbes and host cells, and protect themselves against bacteriophages. While bacterial RNA research has made fundamental contributions to biomedicine and biotechnology, the bulk of our knowledge of RNA biology stems from the study of a handful of aerobic model species. In comparison, RNA research is lagging in many medically relevant obligate anaerobic species, in particular the numerous commensal bacteria comprising our gut microbiota. This review presents a guide to RNA-based regulatory mechanisms in the phylum Bacteroidetes, focusing on the most abundant bacterial genus in the human gut, Bacteroides spp. This includes recent case reports on riboswitches, an mRNA leader, cis- and trans-encoded small RNAs (sRNAs) in Bacteroides spp., and a survey of CRISPR-Cas systems across Bacteroidetes. Recent work from our laboratory now suggests the existence of hundreds of noncoding RNA candidates in Bacteroides thetaiotaomicron, the emerging model organism for functional microbiota research. Based on these collective observations, we predict mechanistic and functional commonalities and differences between Bacteroides sRNAs and those of other model bacteria, and outline open questions and tools needed to boost Bacteroidetes RNA research.
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Affiliation(s)
- Daniel Ryan
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Josef-Schneider-Str. 2/D15, D-97080, Würzburg, Germany
| | - Gianluca Prezza
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Josef-Schneider-Str. 2/D15, D-97080, Würzburg, Germany
| | - Alexander J Westermann
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Josef-Schneider-Str. 2/D15, D-97080, Würzburg, Germany.,Institute of Molecular Infection Biology (IMIB), University of Würzburg, Josef-Schneider-Str. 2/D15, D-97080, Würzburg, Germany
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27
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Soutourina O, Dubois T, Monot M, Shelyakin PV, Saujet L, Boudry P, Gelfand MS, Dupuy B, Martin-Verstraete I. Genome-Wide Transcription Start Site Mapping and Promoter Assignments to a Sigma Factor in the Human Enteropathogen Clostridioides difficile. Front Microbiol 2020; 11:1939. [PMID: 32903654 PMCID: PMC7438776 DOI: 10.3389/fmicb.2020.01939] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/23/2020] [Indexed: 12/12/2022] Open
Abstract
The emerging human enteropathogen Clostridioides difficile is the main cause of diarrhea associated with antibiotherapy. Regulatory pathways underlying the adaptive responses remain understudied and the global view of C. difficile promoter structure is still missing. In the genome of C. difficile 630, 22 genes encoding sigma factors are present suggesting a complex pattern of transcription in this bacterium. We present here the first transcriptional map of the C. difficile genome resulting from the identification of transcriptional start sites (TSS), promoter motifs and operon structures. By 5′-end RNA-seq approach, we mapped more than 1000 TSS upstream of genes. In addition to these primary TSS, this analysis revealed complex structure of transcriptional units such as alternative and internal promoters, potential RNA processing events and 5′ untranslated regions. By following an in silico iterative strategy that used as an input previously published consensus sequences and transcriptomic analysis, we identified candidate promoters upstream of most of protein-coding and non-coding RNAs genes. This strategy also led to refine consensus sequences of promoters recognized by major sigma factors of C. difficile. Detailed analysis focuses on the transcription in the pathogenicity locus and regulatory genes, as well as regulons of transition phase and sporulation sigma factors as important components of C. difficile regulatory network governing toxin gene expression and spore formation. Among the still uncharacterized regulons of the major sigma factors of C. difficile, we defined the SigL regulon by combining transcriptome and in silico analyses. We showed that the SigL regulon is largely involved in amino-acid degradation, a metabolism crucial for C. difficile gut colonization. Finally, we combined our TSS mapping, in silico identification of promoters and RNA-seq data to improve gene annotation and to suggest operon organization in C. difficile. These data will considerably improve our knowledge of global regulatory circuits controlling gene expression in C. difficile and will serve as a useful rich resource for scientific community both for the detailed analysis of specific genes and systems biology studies.
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Affiliation(s)
- Olga Soutourina
- Laboratoire Pathogenèses des Bactéries Anaérobies, Institut Pasteur, UMR CNRS 2001, Université de Paris, Paris, France.,Institut Universitaire de France, Paris, France.,Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Thomas Dubois
- Laboratoire Pathogenèses des Bactéries Anaérobies, Institut Pasteur, UMR CNRS 2001, Université de Paris, Paris, France
| | - Marc Monot
- Laboratoire Pathogenèses des Bactéries Anaérobies, Institut Pasteur, UMR CNRS 2001, Université de Paris, Paris, France
| | | | - Laure Saujet
- Laboratoire Pathogenèses des Bactéries Anaérobies, Institut Pasteur, UMR CNRS 2001, Université de Paris, Paris, France
| | - Pierre Boudry
- Laboratoire Pathogenèses des Bactéries Anaérobies, Institut Pasteur, UMR CNRS 2001, Université de Paris, Paris, France
| | - Mikhail S Gelfand
- Institute for Information Transmission Problems, Moscow, Russia.,Skolkovo Institute of Science and Technology, Moscow, Russia
| | - Bruno Dupuy
- Laboratoire Pathogenèses des Bactéries Anaérobies, Institut Pasteur, UMR CNRS 2001, Université de Paris, Paris, France
| | - Isabelle Martin-Verstraete
- Laboratoire Pathogenèses des Bactéries Anaérobies, Institut Pasteur, UMR CNRS 2001, Université de Paris, Paris, France.,Institut Universitaire de France, Paris, France
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28
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Tollerson R, Ibba M. Translational regulation of environmental adaptation in bacteria. J Biol Chem 2020; 295:10434-10445. [PMID: 32518156 DOI: 10.1074/jbc.rev120.012742] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 06/08/2020] [Indexed: 01/26/2023] Open
Abstract
Bacteria must rapidly respond to both intracellular and environmental changes to survive. One critical mechanism to rapidly detect and adapt to changes in environmental conditions is control of gene expression at the level of protein synthesis. At each of the three major steps of translation-initiation, elongation, and termination-cells use stimuli to tune translation rate and cellular protein concentrations. For example, changes in nutrient concentrations in the cell can lead to translational responses involving mechanisms such as dynamic folding of riboswitches during translation initiation or the synthesis of alarmones, which drastically alter cell physiology. Moreover, the cell can fine-tune the levels of specific protein products using programmed ribosome pausing or inducing frameshifting. Recent studies have improved understanding and revealed greater complexity regarding long-standing paradigms describing key regulatory steps of translation such as start-site selection and the coupling of transcription and translation. In this review, we describe how bacteria regulate their gene expression at the three translational steps and discuss how translation is used to detect and respond to changes in the cellular environment. Finally, we appraise the costs and benefits of regulation at the translational level in bacteria.
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Affiliation(s)
- Rodney Tollerson
- Department of Microbiology and Center for RNA Biology, Ohio State University, Columbus, Ohio, USA
| | - Michael Ibba
- Department of Microbiology and Center for RNA Biology, Ohio State University, Columbus, Ohio, USA
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29
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Kuo ST, Jahn RL, Cheng YJ, Chen YL, Lee YJ, Hollfelder F, Wen JD, Chou HHD. Global fitness landscapes of the Shine-Dalgarno sequence. Genome Res 2020; 30:711-723. [PMID: 32424071 PMCID: PMC7263185 DOI: 10.1101/gr.260182.119] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 04/21/2020] [Indexed: 01/06/2023]
Abstract
Shine-Dalgarno sequences (SD) in prokaryotic mRNA facilitate protein translation by pairing with rRNA in ribosomes. Although conventionally defined as AG-rich motifs, recent genomic surveys reveal great sequence diversity, questioning how SD functions. Here, we determined the molecular fitness (i.e., translation efficiency) of 49 synthetic 9-nt SD genotypes in three distinct mRNA contexts in Escherichia coli. We uncovered generic principles governing the SD fitness landscapes: (1) Guanine contents, rather than canonical SD motifs, best predict the fitness of both synthetic and endogenous SD; (2) the genotype-fitness correlation of SD promotes its evolvability by steadily supplying beneficial mutations across fitness landscapes; and (3) the frequency and magnitude of deleterious mutations increase with background fitness, and adjacent nucleotides in SD show stronger epistasis. Epistasis results from disruption of the continuous base pairing between SD and rRNA. This “chain-breaking” epistasis creates sinkholes in SD fitness landscapes and may profoundly impact the evolution and function of prokaryotic translation initiation and other RNA-mediated processes. Collectively, our work yields functional insights into the SD sequence variation in prokaryotic genomes, identifies a simple design principle to guide bioengineering and bioinformatic analysis of SD, and illuminates the fundamentals of fitness landscapes and molecular evolution.
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Affiliation(s)
- Syue-Ting Kuo
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Ruey-Lin Jahn
- Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Yuan-Ju Cheng
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Yi-Lan Chen
- Genome and Systems Biology Degree Program, Academia Sinica and National Taiwan University, Taipei 10617, Taiwan
| | - Yun-Ju Lee
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan
| | - Florian Hollfelder
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, United Kingdom
| | - Jin-Der Wen
- Genome and Systems Biology Degree Program, Academia Sinica and National Taiwan University, Taipei 10617, Taiwan.,Institute of Molecular and Cellular Biology, National Taiwan University, Taipei 10617, Taiwan
| | - Hsin-Hung David Chou
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan.,Genome and Systems Biology Degree Program, Academia Sinica and National Taiwan University, Taipei 10617, Taiwan
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30
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Wei Y, Xia X. Unique Shine-Dalgarno Sequences in Cyanobacteria and Chloroplasts Reveal Evolutionary Differences in Their Translation Initiation. Genome Biol Evol 2020; 11:3194-3206. [PMID: 31621842 PMCID: PMC6847405 DOI: 10.1093/gbe/evz227] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/15/2019] [Indexed: 12/12/2022] Open
Abstract
Microorganisms require efficient translation to grow and replicate rapidly, and translation is often rate-limited by initiation. A prominent feature that facilitates translation initiation in bacteria is the Shine-Dalgarno (SD) sequence. However, there is much debate over its conservation in Cyanobacteria and in chloroplasts which presumably originated from endosymbiosis of ancient Cyanobacteria. Elucidating the utilization of SD sequences in Cyanobacteria and in chloroplasts is therefore important to understand whether 1) SD role in Cyanobacterial translation has been reduced prior to chloroplast endosymbiosis or 2) translation in Cyanobacteria and in plastid has been subjected to different evolutionary pressures. To test these alternatives, we employed genomic, proteomic, and transcriptomic data to trace differences in SD usage among Synechocystis species, Microcystis aeruginosa, cyanophages, Nicotiana tabacum chloroplast, and Arabidopsis thaliana chloroplast. We corrected their mis-annotated 16S rRNA 3' terminus using an RNA-Seq-based approach to determine their SD/anti-SD locational constraints using an improved measurement DtoStart. We found that cyanophages well-mimic Cyanobacteria in SD usage because both have been under the same selection pressure for SD-mediated initiation. Whereas chloroplasts lost this similarity because the need for SD-facilitated initiation has been reduced in plastids having much reduced genome size and different ribosomal proteins as a result of host-symbiont coevolution. Consequently, SD sequence significantly increases protein expression in Cyanobacteria but not in chloroplasts, and only Cyanobacterial genes compensate for a lack of SD sequence by having weaker secondary structures at the 5' UTR. Our results suggest different evolutionary pressures operate on translation initiation in Cyanobacteria and in chloroplast.
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Affiliation(s)
- Yulong Wei
- Department of Biology, University of Ottawa, Ontario, Canada
| | - Xuhua Xia
- Department of Biology, University of Ottawa, Ontario, Canada.,Ottawa Institute of Systems Biology, University of Ottawa, Ontario, Canada
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31
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Saito K, Green R, Buskirk AR. Translational initiation in E. coli occurs at the correct sites genome-wide in the absence of mRNA-rRNA base-pairing. eLife 2020; 9:55002. [PMID: 32065583 PMCID: PMC7043885 DOI: 10.7554/elife.55002] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 02/14/2020] [Indexed: 12/21/2022] Open
Abstract
Shine-Dalgarno (SD) motifs are thought to play an important role in translational initiation in bacteria. Paradoxically, ribosome profiling studies in E. coli show no correlation between the strength of an mRNA’s SD motif and how efficiently it is translated. Performing profiling on ribosomes with altered anti-Shine-Dalgarno sequences, we reveal a genome-wide correlation between SD strength and ribosome occupancy that was previously masked by other contributing factors. Using the antibiotic retapamulin to trap initiation complexes at start codons, we find that the mutant ribosomes select start sites correctly, arguing that start sites are hard-wired for initiation through the action of other mRNA features. We show that A-rich sequences upstream of start codons promote initiation. Taken together, our genome-wide study reveals that SD motifs are not necessary for ribosomes to determine where initiation occurs, though they do affect how efficiently initiation occurs.
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Affiliation(s)
- Kazuki Saito
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Rachel Green
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, United States.,Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Allen R Buskirk
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, United States
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32
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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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33
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Weiner I, Shahar N, Marco P, Yacoby I, Tuller T. Solving the Riddle of the Evolution of Shine-Dalgarno Based Translation in Chloroplasts. Mol Biol Evol 2019; 36:2854-2860. [DOI: 10.1093/molbev/msz210] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
AbstractChloroplasts originated from an ancient cyanobacterium and still harbor a bacterial-like genome. However, the centrality of Shine–Dalgarno ribosome binding, which predominantly regulates proteobacterial translation initiation, is significantly decreased in chloroplasts. As plastid ribosomal RNA anti-Shine–Dalgarno elements are similar to their bacterial counterparts, these sites alone cannot explain this decline. By computational simulation we show that upstream point mutations modulate the local structure of ribosomal RNA in chloroplasts, creating significantly tighter structures around the anti-Shine–Dalgarno locus, which in-turn reduce the probability of ribosome binding. To validate our model, we expressed two reporter genes (mCherry, hydrogenase) harboring a Shine–Dalgarno motif in the Chlamydomonas reinhardtii chloroplast. Coexpressing them with a 16S ribosomal RNA, modified according to our model, significantly enhances mCherry and hydrogenase expression compared with coexpression with an endogenous 16S gene.
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Affiliation(s)
- Iddo Weiner
- Department of Biomedical Engineering, The Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel
| | - Noam Shahar
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel
| | - Pini Marco
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel
| | - Iftach Yacoby
- School of Plant Sciences and Food Security, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel
| | - Tamir Tuller
- Department of Biomedical Engineering, The Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
- The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
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34
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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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35
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Hockenberry AJ, Jewett MC, Amaral LAN, Wilke CO. Within-Gene Shine-Dalgarno Sequences Are Not Selected for Function. Mol Biol Evol 2019; 35:2487-2498. [PMID: 30085185 DOI: 10.1093/molbev/msy150] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The Shine-Dalgarno (SD) sequence motif facilitates translation initiation and is frequently found upstream of bacterial start codons. However, thousands of instances of this motif occur throughout the middle of protein coding genes in a typical bacterial genome. Here, we use comparative evolutionary analysis to test whether SD sequences located within genes are functionally constrained. We measure the conservation of SD sequences across Enterobacteriales, and find that they are significantly less conserved than expected. Further, the strongest SD sequences are the least conserved whereas we find evidence of conservation for the weakest possible SD sequences given amino acid constraints. Our findings indicate that most SD sequences within genes are likely to be deleterious and removed via selection. To illustrate the origin of these deleterious costs, we show that ATG start codons are significantly depleted downstream of SD sequences within genes, highlighting the constraint that these sequences impose on the surrounding nucleotides to minimize the potential for erroneous translation initiation.
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Affiliation(s)
- Adam J Hockenberry
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL.,Chemistry of Life Processes Institute, Northwestern University, Evanston, IL.,Center for Synthetic Biology, Northwestern University, Evanston, IL.,Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL.,Simpson Querrey Institute, Northwestern University, Evanston, IL
| | - Luís A N Amaral
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL.,Northwestern Institute on Complex Systems, Northwestern University, Evanston, IL
| | - Claus O Wilke
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX
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36
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Reading canonical and modified nucleobases in 16S ribosomal RNA using nanopore native RNA sequencing. PLoS One 2019; 14:e0216709. [PMID: 31095620 PMCID: PMC6522004 DOI: 10.1371/journal.pone.0216709] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 04/27/2019] [Indexed: 11/19/2022] Open
Abstract
The ribosome small subunit is expressed in all living cells. It performs numerous essential functions during translation, including formation of the initiation complex and proofreading of base-pairs between mRNA codons and tRNA anticodons. The core constituent of the small ribosomal subunit is a ~1.5 kb RNA strand in prokaryotes (16S rRNA) and a homologous ~1.8 kb RNA strand in eukaryotes (18S rRNA). Traditional sequencing-by-synthesis (SBS) of rRNA genes or rRNA cDNA copies has achieved wide use as a ‘molecular chronometer’ for phylogenetic studies, and as a tool for identifying infectious organisms in the clinic. However, epigenetic modifications on rRNA are erased by SBS methods. Here we describe direct MinION nanopore sequencing of individual, full-length 16S rRNA absent reverse transcription or amplification. As little as 5 picograms (~10 attomole) of purified E. coli 16S rRNA was detected in 4.5 micrograms of total human RNA. Nanopore ionic current traces that deviated from canonical patterns revealed conserved E. coli 16S rRNA 7-methylguanosine and pseudouridine modifications, and a 7-methylguanosine modification that confers aminoglycoside resistance to some pathological E. coli strains.
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37
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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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RNA-Seq-Based Analysis Reveals Heterogeneity in Mature 16S rRNA 3' Termini and Extended Anti-Shine-Dalgarno Motifs in Bacterial Species. G3-GENES GENOMES GENETICS 2018; 8:3973-3979. [PMID: 30355764 PMCID: PMC6288834 DOI: 10.1534/g3.118.200729] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We present an RNA-Seq based approach to map 3′ end sequences of mature 16S rRNA (3′ TAIL) in bacteria with single-base specificity. Our results show that 3′ TAILs are heterogeneous among species; they contain the core CCUCC anti-Shine-Dalgarno motif, but vary in downstream lengths. Importantly, our findings rectify the mis-annotated 16S rRNAs in 11 out of 13 bacterial species studied herein (covering Cyanobacteria, Deinococcus-Thermus, Firmicutes, Proteobacteria, Tenericutes, and Spirochaetes). Furthermore, our results show that species-specific 3′ TAIL boundaries are retained due to their high complementarity with preferred Shine-Dalgarno sequences, suggesting that 3′ TAIL bases downstream of the canonical CCUCC motif play a more important role in translation initiation than previously reported.
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39
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Abstract
Ribosome profiling accesses the translational step of gene expression via deep sequencing of ribosome-protected mRNA footprints. Pairing of ribosome profiling and transcriptomics data provides a translational efficiency for each gene. Here, the translatome and transcriptome of the model cyanobacterium
Synechocystis
were compared under carbon-replete and carbon starvation conditions. The latter may be experienced when cyanobacteria are cultivated in poorly mixed bioreactors or engineered to be product-secreting cell factories. A small fraction of genes (<200), including stress response genes, showed changes in translational efficiency during carbon starvation, indicating condition-dependent translation-level regulation. We observed ribosome occupancy in untranslated regions, possibly due to an alternative translation initiation mechanism in
Synechocystis.
The higher proportion of ribosomes residing in untranslated regions during carbon starvation may be a mechanism to quickly inactivate superfluous ribosomes. This work provides the first ribosome profiling data for cyanobacteria and reveals new regulation strategies for coping with nutrient limitation.
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40
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Optimization of carbon and energy utilization through differential translational efficiency. Nat Commun 2018; 9:4474. [PMID: 30367068 PMCID: PMC6203783 DOI: 10.1038/s41467-018-06993-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 10/02/2018] [Indexed: 01/19/2023] Open
Abstract
Control of translation is vital to all species. Here we employ a multi-omics approach to decipher condition-dependent translational regulation in the model acetogen Clostridium ljungdahlii. Integration of data from cells grown autotrophically or heterotrophically revealed that pathways critical to carbon and energy metabolism are under strong translational regulation. Major pathways involved in carbon and energy metabolism are not only differentially transcribed and translated, but their translational efficiencies are differentially elevated in response to resource availability under different growth conditions. We show that translational efficiency is not static and that it changes dynamically in response to mRNA expression levels. mRNAs harboring optimized 5'-untranslated region and coding region features, have higher translational efficiencies and are significantly enriched in genes encoding carbon and energy metabolism. In contrast, mRNAs enriched in housekeeping functions harbor sub-optimal features and have lower translational efficiencies. We propose that regulation of translational efficiency is crucial for effectively controlling resource allocation in energy-deprived microorganisms.
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41
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Ten-Caten F, Vêncio RZN, Lorenzetti APR, Zaramela LS, Santana AC, Koide T. Internal RNAs overlapping coding sequences can drive the production of alternative proteins in archaea. RNA Biol 2018; 15:1119-1132. [PMID: 30175688 PMCID: PMC6161675 DOI: 10.1080/15476286.2018.1509661] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Prokaryotic genomes show a high level of information compaction often with different molecules transcribed from the same locus. Although antisense RNAs have been relatively well studied, RNAs in the same strand, internal RNAs (intraRNAs), are still poorly understood. The question of how common is the translation of overlapping reading frames remains open. We address this question in the model archaeon Halobacterium salinarum. In the present work we used differential RNA-seq (dRNA-seq) in H. salinarum NRC-1 to locate intraRNA signals in subsets of internal transcription start sites (iTSS) and establish the open reading frames associated to them (intraORFs). Using C-terminally flagged proteins, we experimentally observed isoforms accurately predicted by intraRNA translation for kef1, acs3 and orc4 genes. We also recovered from the literature and mass spectrometry databases several instances of protein isoforms consistent with intraRNA translation such as the gas vesicle protein gene gvpC1. We found evidence for intraRNAs in horizontally transferred genes such as the chaperone dnaK and the aerobic respiration related cydA in both H. salinarum and Escherichia coli. Also, intraRNA translation evidence in H. salinarum, E. coli and yeast of a universal elongation factor (aEF-2, fusA and eEF-2) suggests that this is an ancient phenomenon present in all domains of life.
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Affiliation(s)
- Felipe Ten-Caten
- a Department of Biochemistry and Immunology , Ribeirão Preto Medical School, University of São Paulo , Ribeirão Preto , Brazil
| | - Ricardo Z N Vêncio
- b Department of Computation and Mathematics, Faculdade de Filosofia , Ciências e Letras de Ribeirão Preto, University of São Paulo , Ribeirão Preto , Brazil
| | - Alan Péricles R Lorenzetti
- a Department of Biochemistry and Immunology , Ribeirão Preto Medical School, University of São Paulo , Ribeirão Preto , Brazil
| | - Livia Soares Zaramela
- a Department of Biochemistry and Immunology , Ribeirão Preto Medical School, University of São Paulo , Ribeirão Preto , Brazil
| | - Ana Carolina Santana
- c Department of Cell and Molecular Biology and Pathogenic Bioagents , Ribeirão Preto Medical School, University of São Paulo , Ribeirão Preto , Brazil
| | - Tie Koide
- a Department of Biochemistry and Immunology , Ribeirão Preto Medical School, University of São Paulo , Ribeirão Preto , Brazil
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42
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Prokaryotic coding regions have little if any specific depletion of Shine-Dalgarno motifs. PLoS One 2018; 13:e0202768. [PMID: 30138485 PMCID: PMC6107199 DOI: 10.1371/journal.pone.0202768] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 08/08/2018] [Indexed: 11/19/2022] Open
Abstract
The Shine-Dalgarno motif occurs in front of prokaryotic start codons, and is complementary to the 3’ end of the 16S ribosomal RNA. Hybridization between the Shine-Dalgarno sequence and the anti-Shine-Dalgarno region of the16S rRNA (CCUCCU) directs the ribosome to the start AUG of the mRNA for translation. Shine-Dalgarno-like motifs (AGGAGG in E. coli) are depleted from open reading frames of most prokaryotes. This may be because hybridization of the 16S rRNA at Shine-Dalgarnos inside genes would slow translation or induce internal initiation. However, we analyzed 128 species from diverse phyla where the 16S rRNA gene(s) lack the anti-Shine-Dalgarno sequence, and so the 16S rRNA is incapable of interacting with Shine-Dalgarno-like sequences. Despite this lack of an anti-Shine-Dalgarno, half of these species still displayed depletion of Shine-Dalgarno-like sequences when analyzed by previous methods. Depletion of the same G-rich sequences was seen by these methods even in eukaryotes, which do not use the Shine-Dalgarno mechanism. We suggest previous methods are partly detecting a non-specific depletion of G-rich sequences. Alternative informatics approaches show that most prokaryotes have only slight, if any, specific depletion of Shine-Dalgarno-like sequences from open reading frames. Together with recent evidence that ribosomes do not pause at ORF-internal Shine-Dalgarno motifs, these results suggest the presence of ORF-internal Shine-Dalgarno-like motifs may be inconsequential, perhaps because internal regions of prokaryotic mRNAs may be structurally “shielded” from translation initiation.
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43
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Amin MR, Yurovsky A, Chen Y, Skiena S, Futcher B. Re-annotation of 12,495 prokaryotic 16S rRNA 3' ends and analysis of Shine-Dalgarno and anti-Shine-Dalgarno sequences. PLoS One 2018; 13:e0202767. [PMID: 30138483 PMCID: PMC6107228 DOI: 10.1371/journal.pone.0202767] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 08/08/2018] [Indexed: 01/28/2023] Open
Abstract
We examined 20,648 prokaryotic unique taxids with respect to the annotation of the 3' end of the 16S rRNA, which contains the anti-Shine-Dalgarno sequence. We used the sequence of highly conserved helix 45 of the 16S rRNA as a guide. By this criterion, 8,153 annotated 3' ends correctly included the anti-Shine-Dalgarno sequence, but 12,495 were foreshortened or otherwise mis-annotated, missing part or all of the anti-Shine-Dalgarno sequence, which immediately follows helix 45. We re-annotated, giving a total of 20,648 16S rRNA 3' ends. The vast majority indeed contained a consensus anti-Shine-Dalgarno sequence, embedded in a highly conserved 13 base "tail". However, 128 exceptional organisms had either a variant anti-Shine-Dalgarno, or no recognizable anti-Shine-Dalgarno, in their 16S rRNA(s). For organisms both with and without an anti-Shine-Dalgarno, we identified the Shine-Dalgarno motifs actually enriched in front of each organism's open reading frames. This showed to what extent the Shine-Dalgarno motifs correlated with anti-Shine Dalgarno motifs. In general, organisms whose rRNAs lacked a perfect anti-Shine-Dalgarno motif also lacked a recognizable Shine-Dalgarno. For organisms whose 16S rRNAs contained a perfect anti-Shine-Dalgarno motif, a variety of results were obtained. We found one genus, Alteromonas, where several taxids apparently maintain two different types of 16S rRNA genes, with different, but conserved, antiSDs. The fact that some organisms do not seem to have or use Shine-Dalgarno motifs supports the idea that prokaryotes have other robust mechanisms for recognizing start codons for translation.
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Affiliation(s)
- Mohammad Ruhul Amin
- Dept. of Computer Science, Stony Brook University, Stony Brook, NY, United States of America
| | - Alisa Yurovsky
- Dept. of Computer Science, Stony Brook University, Stony Brook, NY, United States of America
| | - Yuping Chen
- Dept. of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, United States of America
| | - Steve Skiena
- Dept. of Computer Science, Stony Brook University, Stony Brook, NY, United States of America
| | - Bruce Futcher
- Dept. of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, United States of America
- * E-mail:
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44
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Karim AA, Gestaut DR, Fincker M, Ruth JC, Holmes EC, Sheu W, Spormann AM. Fine-Tuned Protein Production in Methanosarcina acetivorans C2A. ACS Synth Biol 2018; 7:1874-1885. [PMID: 29920209 DOI: 10.1021/acssynbio.8b00062] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Methanogenic archaea can be integrated into a sustainable, carbon-neutral cycle for producing organic chemicals from C1 compounds if the rate, yield, and titer of product synthesis can be improved using metabolic engineering. However, metabolic engineering techniques are limited in methanogens by insufficient methods for controlling cellular protein levels. We conducted a systematic approach to tune protein levels in Methanosarcina acetivorans C2A, a model methanogen, by regulating transcription and translation initiation. Rationally designed core promoter and ribosome binding site mutations in M. acetivorans C2A resulted in a predicable change in protein levels over a 60 fold range. The overall range of protein levels was increased an additional 3 fold by introducing the 5' untranslated region of the mcrB transcript. This work demonstrates a wide range of precisely controlled protein levels in M. acetivorans C2A, which will help facilitate systematic metabolic engineering efforts in methanogens.
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Affiliation(s)
- Ann A. Karim
- Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
| | - Daniel R. Gestaut
- Department of Biology, Stanford University, Stanford, California 94305, United States
| | - Maeva Fincker
- Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
| | - John C. Ruth
- Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States
| | - Eric C. Holmes
- Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States
| | - Wayne Sheu
- Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States
| | - Alfred M. Spormann
- Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
- Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States
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45
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Stiller LM, Galinski EA, Witt EMHJ. Engineering the Salt-Inducible Ectoine Promoter Region of Halomonas elongata for Protein Expression in a Unique Stabilizing Environment. Genes (Basel) 2018; 9:genes9040184. [PMID: 29597294 PMCID: PMC5924526 DOI: 10.3390/genes9040184] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 03/19/2018] [Accepted: 03/21/2018] [Indexed: 01/11/2023] Open
Abstract
It has been firmly established that organic osmolytes (compatible solutes) of halophilic Bacteria and Archaea have positive effects on conformation and activity of proteins, and may therefore improve their functional production. In particular, the amino acid derivative ectoine is known for its conformational stabilization, aggregation suppression, and radical protection properties. The natural producer and industrial production strain Halomonas elongata accumulates ectoine in the cytoplasm, and as a result offers a unique stabilizing environment for recombinant proteins. For the construction of broad hoast range vector systems with fluorescent reporter proteins, we chose the salt-inducible promoter region of the ectoine gene cluster (promA). A closer inspection of the genetic background revealed that its combination of sigma 38 (σ38) and sigma 70 (σ70) promoters was followed by a weak ribosomal binding site (RBS). This inspired a systematic approach for the construction of a promA-based vector series with a synthetic RBS region using the RBS Calculator v2.0, which resulted in a greatly improved salt-dependent expression-even in a deletion construct lacking the σ38 promoter. To expand the application range of this expression system, we looked further into the possible export of recombinant proteins into the periplasm. Both sec and tat leader sequences from H. elongata proved to be suitable for directed periplasmic transport into an extreme environment of freely selectable ionic strength.
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Affiliation(s)
- Lisa M Stiller
- Institute of Microbiology and Biotechnology, Rheinische Friedrich-Wilhelms University Bonn, 53115 Bonn, Germany.
| | - Erwin A Galinski
- Institute of Microbiology and Biotechnology, Rheinische Friedrich-Wilhelms University Bonn, 53115 Bonn, Germany.
| | - Elisabeth M H J Witt
- Institute of Microbiology and Biotechnology, Rheinische Friedrich-Wilhelms University Bonn, 53115 Bonn, Germany.
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46
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Skiba MA, Maloney FP, Dan Q, Fraley AE, Aldrich CC, Smith JL, Brown WC. PKS-NRPS Enzymology and Structural Biology: Considerations in Protein Production. Methods Enzymol 2018; 604:45-88. [PMID: 29779664 PMCID: PMC5992914 DOI: 10.1016/bs.mie.2018.01.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The structural diversity and complexity of marine natural products have made them a rich and productive source of new bioactive molecules for drug development. The identification of these new compounds has led to extensive study of the protein constituents of the biosynthetic pathways from the producing microbes. Essential processes in the dissection of biosynthesis have been the elucidation of catalytic functions and the determination of 3D structures for enzymes of the polyketide synthases and nonribosomal peptide synthetases that carry out individual reactions. The size and complexity of these proteins present numerous difficulties in the process of going from gene to structure. Here, we review the problems that may be encountered at the various steps of this process and discuss some of the solutions devised in our and other labs for the cloning, production, purification, and structure solution of complex proteins using Escherichia coli as a heterologous host.
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Affiliation(s)
| | | | - Qingyun Dan
- University of Michigan, Ann Arbor, MI, United States
| | - Amy E Fraley
- University of Michigan, Ann Arbor, MI, United States
| | | | - Janet L Smith
- University of Michigan, Ann Arbor, MI, United States.
| | - W Clay Brown
- University of Michigan, Ann Arbor, MI, United States.
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47
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Ludwig P, Huber M, Lehr M, Wegener M, Zerulla K, Lange C, Soppa J. Non-canonical Escherichia coli transcripts lacking a Shine-Dalgarno motif have very different translational efficiencies and do not form a coherent group. MICROBIOLOGY-SGM 2018; 164:646-658. [PMID: 29469690 DOI: 10.1099/mic.0.000619] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Translation initiation in 50-70 % of transcripts in Escherichia coli requires base pairing between the Shine-Dalgarno (SD) motif in the mRNA and the anti-SD motif at the 3' end of the 16S rRNA. However, 30-50 % of E. coli transcripts are non-canonical and are not preceded by an SD motif. The 5' ends of 44 E. coli transcripts were determined, all of which contained a 5'-UTR (no leaderless transcripts), but only a minority contained an SD motif. The 5'-UTR lengths were compared with those listed in RegulonDB and reported in previous publications, and the identities and differences were obtained in all possible combinations. We aimed to quantify the translational efficiencies of non-canonical 5'-UTRs using GusA reporter gene assays and Northern blot analyses. Ten non-canonical 5'-UTRs and two control 5'-UTRs with an SD motif were cloned upstream of the gusA gene. The translational efficiencies were quantified under five different conditions (different growth rates via two different temperatures and two different carbon sources, and heat shock). The translational efficiencies of the non-canonical 5'-UTRs varied widely, from 5 to 384 % of the positive control. In addition, the non-canonical transcripts did not exhibit a common regulatory pattern with changing environmental parameters. No correlation could be observed between the translational efficiencies of the non-canonical 5'-UTRs and their lengths, sequences, GC content, or predicted secondary structures. The introduction of an SD motif enhanced the translational efficiency of a poorly translated non-canonical transcript, while the efficiency of a well-translated non-canonical transcript remained unchanged. Taken together, the mechanisms of translation initiation at non-canonical transcripts in E. coli still need to be elucidated.
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Affiliation(s)
- Petra Ludwig
- Goethe University, Institute for Molecular Biosciences, Max-von-Laue-Str. 9, D-60438 Frankfurt, Germany
| | - Madeleine Huber
- Goethe University, Institute for Molecular Biosciences, Max-von-Laue-Str. 9, D-60438 Frankfurt, Germany
| | - Matthias Lehr
- Goethe University, Institute for Molecular Biosciences, Max-von-Laue-Str. 9, D-60438 Frankfurt, Germany
| | - Marius Wegener
- Goethe University, Institute for Molecular Biosciences, Max-von-Laue-Str. 9, D-60438 Frankfurt, Germany
| | - Karolin Zerulla
- Goethe University, Institute for Molecular Biosciences, Max-von-Laue-Str. 9, D-60438 Frankfurt, Germany
| | - Christian Lange
- Goethe University, Institute for Molecular Biosciences, Max-von-Laue-Str. 9, D-60438 Frankfurt, Germany
| | - Joerg Soppa
- Goethe University, Institute for Molecular Biosciences, Max-von-Laue-Str. 9, D-60438 Frankfurt, Germany
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48
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Wei Y, Silke JR, Xia X. Elucidating the 16S rRNA 3' boundaries and defining optimal SD/aSD pairing in Escherichia coli and Bacillus subtilis using RNA-Seq data. Sci Rep 2017; 7:17639. [PMID: 29247194 PMCID: PMC5732282 DOI: 10.1038/s41598-017-17918-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 12/04/2017] [Indexed: 11/09/2022] Open
Abstract
Bacterial translation initiation is influenced by base pairing between the Shine-Dalgarno (SD) sequence in the 5' UTR of mRNA and the anti-SD (aSD) sequence at the free 3' end of the 16S rRNA (3' TAIL) due to: 1) the SD/aSD sequence binding location and 2) SD/aSD binding affinity. In order to understand what makes an SD/aSD interaction optimal, we must define: 1) terminus of the 3' TAIL and 2) extent of the core aSD sequence within the 3' TAIL. Our approach to characterize these components in Escherichia coli and Bacillus subtilis involves 1) mapping the 3' boundary of the mature 16S rRNA using high-throughput RNA sequencing (RNA-Seq), and 2) identifying the segment within the 3' TAIL that is strongly preferred in SD/aSD pairing. Using RNA-Seq data, we resolve previous discrepancies in the reported 3' TAIL in B. subtilis and recovered the established 3' TAIL in E. coli. Furthermore, we extend previous studies to suggest that both highly and lowly expressed genes favor SD sequences with intermediate binding affinity, but this trend is exclusive to SD sequences that complement the core aSD sequences defined herein.
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Affiliation(s)
- Yulong Wei
- Department of Biology, University of Ottawa, 30 Marie Curie, P.O. Box 450, Station A, Ottawa, Ontario, Canada
| | - Jordan R Silke
- Department of Biology, University of Ottawa, 30 Marie Curie, P.O. Box 450, Station A, Ottawa, Ontario, Canada
| | - Xuhua Xia
- Department of Biology, University of Ottawa, 30 Marie Curie, P.O. Box 450, Station A, Ottawa, Ontario, Canada. .,Ottawa Institute of Systems Biology, Ottawa, Ontario, K1H 8M5, Canada.
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49
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Hockenberry AJ, Stern AJ, Amaral LAN, Jewett MC. Diversity of Translation Initiation Mechanisms across Bacterial Species Is Driven by Environmental Conditions and Growth Demands. Mol Biol Evol 2017; 35:582-592. [PMID: 29220489 PMCID: PMC5850609 DOI: 10.1093/molbev/msx310] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The Shine-Dalgarno (SD) sequence motif is frequently found upstream of protein coding genes and is thought to be the dominant mechanism of translation initiation used by bacteria. Experimental studies have shown that the SD sequence facilitates start codon recognition and enhances translation initiation by directly interacting with the highly conserved anti-SD sequence on the 30S ribosomal subunit. However, the proportion of SD-led genes within a genome varies across species and the factors governing this variation in translation initiation mechanisms remain largely unknown. Here, we conduct a phylogenetically informed analysis and find that species capable of rapid growth contain a higher proportion of SD-led genes throughout their genomes. We show that SD sequence utilization covaries with a suite of genomic features that are important for efficient translation initiation and elongation. In addition to these endogenous genomic factors, we further show that exogenous environmental factors may influence the evolution of translation initiation mechanisms by finding that thermophilic species contain significantly more SD-led genes than mesophiles. Our results demonstrate that variation in translation initiation mechanisms across bacterial species is predictable and is a consequence of differential life-history strategies related to maximum growth rate and environmental-specific constraints.
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Affiliation(s)
- Adam J Hockenberry
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
- Interdisciplinary Program in Biological Sciences, Northwestern University, Evanston, IL, USA
| | - Aaron J Stern
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
| | - Luís A N Amaral
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
- Northwestern Institute for Complex Systems, Northwestern University, Evanston, IL, USA
- Department of Physics and Astronomy, Northwestern University, Evanston, IL, USA
- Corresponding authors: E-mails: ;
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
- Northwestern Institute for Complex Systems, Northwestern University, Evanston, IL, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, USA
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Evanston, IL, USA
- Corresponding authors: E-mails: ;
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50
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Scharff LB, Ehrnthaler M, Janowski M, Childs LH, Hasse C, Gremmels J, Ruf S, Zoschke R, Bock R. Shine-Dalgarno Sequences Play an Essential Role in the Translation of Plastid mRNAs in Tobacco. THE PLANT CELL 2017; 29:3085-3101. [PMID: 29133466 PMCID: PMC5757275 DOI: 10.1105/tpc.17.00524] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 10/27/2017] [Accepted: 11/08/2017] [Indexed: 05/23/2023]
Abstract
In prokaryotic systems, the translation initiation of many, though not all, mRNAs depends on interaction between a sequence element upstream of the start codon (the Shine-Dalgarno sequence [SD]) and a complementary sequence in the 3' end of the 16S rRNA (anti-Shine-Dalgarno sequence [aSD]). Although many chloroplast mRNAs harbor putative SDs in their 5' untranslated regions and the aSD displays strong conservation, the functional relevance of SD-aSD interactions in plastid translation is unclear. Here, by generating transplastomic tobacco (Nicotiana tabacum) mutants with point mutations in the aSD coupled with genome-wide analysis of translation by ribosome profiling, we provide a global picture of SD-dependent translation in plastids. We observed a pronounced correlation between weakened predicted SD-aSD interactions and reduced translation efficiency. However, multiple lines of evidence suggest that the strength of the SD-aSD interaction is not the only determinant of the translational output of many plastid mRNAs. Finally, the translation efficiency of mRNAs with strong secondary structures around the start codon is more dependent on the SD-aSD interaction than weakly structured mRNAs. Thus, our data reveal the importance of the aSD in plastid translation initiation, uncover chloroplast genes whose translation is influenced by SD-aSD interactions, and provide insights into determinants of translation efficiency in plastids.
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Affiliation(s)
- Lars B Scharff
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Miriam Ehrnthaler
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Marcin Janowski
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Liam H Childs
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Claudia Hasse
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Jürgen Gremmels
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Stephanie Ruf
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Reimo Zoschke
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, D-14476 Potsdam-Golm, Germany
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