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Žedaveinytė R, Meers C, Le HC, Mortman EE, Tang S, Lampe GD, Pesari SR, Gelsinger DR, Wiegand T, Sternberg SH. Antagonistic conflict between transposon-encoded introns and guide RNAs. Science 2024; 385:eadm8189. [PMID: 38991068 DOI: 10.1126/science.adm8189] [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: 11/07/2023] [Accepted: 05/08/2024] [Indexed: 07/13/2024]
Abstract
TnpB nucleases represent the evolutionary precursors to CRISPR-Cas12 and are widespread in all domains of life. IS605-family TnpB homologs function as programmable RNA-guided homing endonucleases in bacteria, driving transposon maintenance through DNA double-strand break-stimulated homologous recombination. In this work, we uncovered molecular mechanisms of the transposition life cycle of IS607-family elements that, notably, also encode group I introns. We identified specific features for a candidate "IStron" from Clostridium botulinum that allow the element to carefully control the relative levels of spliced products versus functional guide RNAs. Our results suggest that IStron transcripts evolved an ability to balance competing and mutually exclusive activities that promote selfish transposon spread while limiting adverse fitness costs on the host. Collectively, this work highlights molecular innovation in the multifunctional utility of transposon-encoded noncoding RNAs.
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Affiliation(s)
- Rimantė Žedaveinytė
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Chance Meers
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Hoang C Le
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Edan E Mortman
- Department of Genetics and Development, Columbia University, New York, NY 10032, USA
| | - Stephen Tang
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - George D Lampe
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Sanjana R Pesari
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Diego R Gelsinger
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Tanner Wiegand
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Samuel H Sternberg
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
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2
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Wiegand T, Hoffmann FT, Walker MWG, Tang S, Richard E, Le HC, Meers C, Sternberg SH. TnpB homologues exapted from transposons are RNA-guided transcription factors. Nature 2024; 631:439-448. [PMID: 38926585 DOI: 10.1038/s41586-024-07598-4] [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: 11/27/2023] [Accepted: 05/23/2024] [Indexed: 06/28/2024]
Abstract
Transposon-encoded tnpB and iscB genes encode RNA-guided DNA nucleases that promote their own selfish spread through targeted DNA cleavage and homologous recombination1-4. These widespread gene families were repeatedly domesticated over evolutionary timescales, leading to the emergence of diverse CRISPR-associated nucleases including Cas9 and Cas12 (refs. 5,6). We set out to test the hypothesis that TnpB nucleases may have also been repurposed for novel, unexpected functions other than CRISPR-Cas adaptive immunity. Here, using phylogenetics, structural predictions, comparative genomics and functional assays, we uncover multiple independent genesis events of programmable transcription factors, which we name TnpB-like nuclease-dead repressors (TldRs). These proteins use naturally occurring guide RNAs to specifically target conserved promoter regions of the genome, leading to potent gene repression in a mechanism akin to CRISPR interference technologies invented by humans7. Focusing on a TldR clade found broadly in Enterobacteriaceae, we discover that bacteriophages exploit the combined action of TldR and an adjacently encoded phage gene to alter the expression and composition of the host flagellar assembly, a transformation with the potential to impact motility8, phage susceptibility9, and host immunity10. Collectively, this work showcases the diverse molecular innovations that were enabled through repeated exaptation of transposon-encoded genes, and reveals the evolutionary trajectory of diverse RNA-guided transcription factors.
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Affiliation(s)
- Tanner Wiegand
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Florian T Hoffmann
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Matt W G Walker
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Stephen Tang
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Egill Richard
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Hoang C Le
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Chance Meers
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Samuel H Sternberg
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
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3
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Daniels MG, Werner ME, Li RT, Pascal SM. Exploration of Potential Broad-Spectrum Antiviral Targets in the Enterovirus Replication Element: Identification of Six Distinct 5' Cloverleaves. Viruses 2024; 16:1009. [PMID: 39066172 PMCID: PMC11281424 DOI: 10.3390/v16071009] [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: 05/16/2024] [Revised: 06/18/2024] [Accepted: 06/21/2024] [Indexed: 07/28/2024] Open
Abstract
Enterovirus genomic replication initiates at a predicted RNA cloverleaf (5'CL) at the 5' end of the RNA genome. The 5'CL contains one stem (SA) and three stem-loops (SLB, SLC, SLD). Here, we present an analysis of 5'CL conservation and divergence for 209 human health-related serotypes from the enterovirus genus, including enterovirus and rhinovirus species. Phylogenetic analysis indicates six distinct 5'CL serotypes that only partially correlate with the species definition. Additional findings include that 5'CL sequence conservation is higher between the EV species than between the RV species, the 5'CL of EVA and EVB are nearly identical, and RVC has the lowest 5'CL conservation. Regions of high conservation throughout all species include SA and the loop and nearby bases of SLB, which is consistent with known protein interactions at these sites. In addition to the known protein binding site for the Poly-C binding protein in the loop of SLB, other conserved consecutive cytosines in the stems of SLB and SLC provide additional potential interaction sites that have not yet been explored. Other sites of conservation, including the predicted bulge of SLD and other conserved stem, loop, and junction regions, are more difficult to explain and suggest additional interactions or structural requirements that are not yet fully understood. This more intricate understanding of sequence and structure conservation and variability in the 5'CL may assist in the development of broad-spectrum antivirals against a wide range of enteroviruses, while better defining the range of virus isotypes expected to be affected by a particular antiviral.
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Affiliation(s)
- Morgan G. Daniels
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA 23529, USA; (M.G.D.); (M.E.W.)
| | - Meagan E. Werner
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA 23529, USA; (M.G.D.); (M.E.W.)
| | - Rockwell T. Li
- Math and Science Academy, Ocean Lakes High School, Virginia Beach, VA 23454, USA;
| | - Steven M. Pascal
- Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA 23529, USA; (M.G.D.); (M.E.W.)
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4
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von Löhneysen S, Spicher T, Varenyk Y, Yao HT, Lorenz R, Hofacker I, Stadler PF. Phylogenetic and Chemical Probing Information as Soft Constraints in RNA Secondary Structure Prediction. J Comput Biol 2024; 31:549-563. [PMID: 38935442 DOI: 10.1089/cmb.2024.0519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2024] Open
Abstract
Extrinsic, experimental information can be incorporated into thermodynamics-based RNA folding algorithms in the form of pseudo-energies. Evolutionary conservation of RNA secondary structure elements is detectable in alignments of phylogenetically related sequences and provides evidence for the presence of certain base pairs that can also be converted into pseudo-energy contributions. We show that the centroid base pairs computed from a consensus folding model such as RNAalifold result in a substantial improvement of the prediction accuracy for single sequences. Evidence for specific base pairs turns out to be more informative than a position-wise profile for the conservation of the pairing status. A comparison with chemical probing data, furthermore, strongly suggests that phylogenetic base pairing data are more informative than position-specific data on (un)pairedness as obtained from chemical probing experiments. In this context we demonstrate, in addition, that the conversion of signal from probing data into pseudo-energies is possible using thermodynamic structure predictions as a reference instead of known RNA structures.
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Affiliation(s)
- Sarah von Löhneysen
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, Universität Leipzig, Leipzig, Germany
| | - Thomas Spicher
- Institute for Theoretical Chemistry, University of Vienna, Vienna, Austria
- UniVie Doctoral School Computer Science (DoCS), University of Vienna, Vienna, Austria
| | - Yuliia Varenyk
- Institute for Theoretical Chemistry, University of Vienna, Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical, University of Vienna, Vienna, Austria
| | - Hua-Ting Yao
- Institute for Theoretical Chemistry, University of Vienna, Vienna, Austria
| | - Ronny Lorenz
- Institute for Theoretical Chemistry, University of Vienna, Vienna, Austria
| | - Ivo Hofacker
- Institute for Theoretical Chemistry, University of Vienna, Vienna, Austria
| | - Peter F Stadler
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, Universität Leipzig, Leipzig, Germany
- Institute for Theoretical Chemistry, University of Vienna, Vienna, Austria
- Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany
- Facultad de Ciencias, Universidad Nacional de Colombia, Bogotá, Colombia
- Santa Fe Institute, Santa Fe, New Mexico, USA
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5
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Liu Y, Fu X, Wang Y, Liu J, Liu Y, Li C, Dong J. Exploring Barbronia species diversity and phylogenetic relationship within Suborder Erpobdelliformes (Clitellata: Annelida). PeerJ 2024; 12:e17480. [PMID: 38827288 PMCID: PMC11144392 DOI: 10.7717/peerj.17480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 05/07/2024] [Indexed: 06/04/2024] Open
Abstract
Background Barbronia, a genus of freshwater macrophagous leeches, belongs to Erpobdelliformes (Salifidae: Clitellata: Annelida), and B. weberi, a well-known leech within this genus, has a worldwide distribution. However, the systematics of Barbronia have not yet been adequately investigated, primarily due to a few molecular markers, and only 20 Barbronia sequences available in the GenBank database. This gap significantly limits our understanding of the Barbronia species identification, as well as the phylogenetic placement of the genus Barbronia within Salifidae. Methods Next-generation sequencing (NGS) was used to simultaneously capture the entire mitochondrial genome and the full-length 18S/28S rDNA sequences. The species boundary of Barbronia species was estimated using bGMYC and bPTP methods, based on all available Barbronia COI sequences. Uncorrected COI p-distance was calculated in MEGA. A molecular data matrix consisting of four loci (COI, 12S, 18S, and 28S rDNA) for outgroups (three Haemopis leeches) and 49 erpobdellid leeches, representing eight genera within the Suborder Erpobdelliformes was aligned using MAFFT and LocARNA. This matrix was used to reconstruct the phylogenetic relationship of Barbronia via Bayesian inference (BI) and the maximum likelihood (ML) method. Results The full lengths of the mitochondrial genome, 18S and 28S rDNAs of B. cf. gwalagwalensis, are 14847 bp, 1876 bp 1876 bp, and 2863 bp, respectively. Both bGMYC and bPTP results based on COI data are generally congruent, suggesting that the previously proposed taxa (B. arcana, B. weberi formosana, and B. wuttkei or Erpobdella wuttkei) are synonyms of B. weberi. The specimens listed in the B. gwalagwalensis group, however, are split into at least two Primary Species Hypotheses (PSHs). The p-distance of the first PSH is less than 1.3% but increased to 4.5% when including the secondary PSH (i.e., B. cf. gwalagwalensis). In comparison, the interspecific p-distance between the B. weberi group and the B. gwalagwalensis group ranged from 6.4% to 8.7%, and the intraspecific p-distance within the B. weberi group is less than 0.8%. Considering the species delimitation results and the sufficient large p-distance, the specimen sampled in China is treated as B. cf. gwalagwalensis. The monophyly of the four Erpobdelliformes families Salifidae, Orobdellidae, Gastrostomobdellidae sensu stricto and Erpobdellidae is well supported in ML and BI analysis based on a data of four markers. Within the Salifidae, a well-supported Barbronia is closely related to a clade containing Odontobdella and Mimobdella, and these three genera are sister to a clade consisted of Salifa and Linta. According to the results of this study, the strategy of simultaneous obtaining both whole mitochondria and nuclear markers from extensively sampled Salifids species using NGS is expected to fathom both the species diversity of B. gwalagwalensis and the evolutionary relationship of Salifidae.
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Affiliation(s)
- Yingkui Liu
- Jiangsu Key Laboratory of Brain Disease Bioinformation, Research Center for Biochemistry & Molecular Biology, Xuzhou Medical University, Xuzhou, Jiangsu, People’s Republic of China
- School of Life Science, Xuzhou Medical University, Xuzhou, Jiangsu, People’s Republic of China
| | - Xinxin Fu
- Jiangsu Key Laboratory of Brain Disease Bioinformation, Research Center for Biochemistry & Molecular Biology, Xuzhou Medical University, Xuzhou, Jiangsu, People’s Republic of China
| | - Yu Wang
- Jiangsu Key Laboratory of Brain Disease Bioinformation, Research Center for Biochemistry & Molecular Biology, Xuzhou Medical University, Xuzhou, Jiangsu, People’s Republic of China
| | - Jing Liu
- Jiangsu Key Laboratory of Brain Disease Bioinformation, Research Center for Biochemistry & Molecular Biology, Xuzhou Medical University, Xuzhou, Jiangsu, People’s Republic of China
| | - Yong Liu
- Jiangsu Key Laboratory of Brain Disease Bioinformation, Research Center for Biochemistry & Molecular Biology, Xuzhou Medical University, Xuzhou, Jiangsu, People’s Republic of China
- School of Life Science, Xuzhou Medical University, Xuzhou, Jiangsu, People’s Republic of China
| | - Chong Li
- Jiangsu Key Laboratory of Brain Disease Bioinformation, Research Center for Biochemistry & Molecular Biology, Xuzhou Medical University, Xuzhou, Jiangsu, People’s Republic of China
- School of Life Science, Xuzhou Medical University, Xuzhou, Jiangsu, People’s Republic of China
| | - Jiajia Dong
- Jiangsu Key Laboratory of Brain Disease Bioinformation, Research Center for Biochemistry & Molecular Biology, Xuzhou Medical University, Xuzhou, Jiangsu, People’s Republic of China
- School of Life Science, Xuzhou Medical University, Xuzhou, Jiangsu, People’s Republic of China
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6
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Yang TH. DEBFold: Computational Identification of RNA Secondary Structures for Sequences across Structural Families Using Deep Learning. J Chem Inf Model 2024; 64:3756-3766. [PMID: 38648189 PMCID: PMC11094721 DOI: 10.1021/acs.jcim.4c00458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 04/09/2024] [Accepted: 04/09/2024] [Indexed: 04/25/2024]
Abstract
It is now known that RNAs play more active roles in cellular pathways beyond simply serving as transcription templates. These biological mechanisms might be mediated by higher RNA stereo conformations, triggering the need to understand RNA secondary structures first. However, experimental protocols for solving RNA structures are unavailable for large-scale investigation due to their high costs and time-consuming nature. Various computational tools were thus developed to predict the RNA secondary structures from sequences. Recently, deep networks have been investigated to help predict RNA structures directly from their sequences. However, existing deep-learning-based tools are more or less suffering from model overfitting due to their complicated problem formulation and defective model training processes, limiting their applications across sequences from different structural families. In this research, we designed a two-stage RNA structure prediction strategy called DEBFold (deep ensemble boosting and folding) based on convolution encoding/decoding and self-attention mechanisms to enhance the existing thermodynamic structure models. Moreover, the model training process followed rigorous steps to achieve an acceptable prediction generalization. On the family-wise reserved test sets and the PDB-derived test set, DEBFold achieves better structure prediction performance over traditional tools and existing deep-learning methods. In summary, we obtained a cutting-edge deep-learning-based structure prediction tool with supreme across-family generalization performance. The DEBFold tool can be accessed at https://cobis.bme.ncku.edu.tw/DEBFold/.
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Affiliation(s)
- Tzu-Hsien Yang
- Department
of Biomedical Engineering, National Cheng
Kung University, No.1, University Road, Tainan 701, Taiwan
- Medical
Device Innovation Center, National Cheng
Kung University, No.1,
University Road, Tainan 701, Taiwan
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7
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Tang S, Conte V, Zhang DJ, Žedaveinytė R, Lampe GD, Wiegand T, Tang LC, Wang M, Walker MW, George JT, Berchowitz LE, Jovanovic M, Sternberg SH. De novo gene synthesis by an antiviral reverse transcriptase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.08.593200. [PMID: 38766058 PMCID: PMC11100668 DOI: 10.1101/2024.05.08.593200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Bacteria defend themselves from viral infection using diverse immune systems, many of which sense and target foreign nucleic acids. Defense-associated reverse transcriptase (DRT) systems provide an intriguing counterpoint to this immune strategy by instead leveraging DNA synthesis, but the identities and functions of their DNA products remain largely unknown. Here we show that DRT2 systems execute an unprecedented immunity mechanism that involves de novo gene synthesis via rolling-circle reverse transcription of a non-coding RNA (ncRNA). Unbiased profiling of RT-associated RNA and DNA ligands in DRT2-expressing cells revealed that reverse transcription generates concatenated cDNA repeats through programmed template jumping on the ncRNA. The presence of phage then triggers second-strand cDNA synthesis, leading to the production of long double-stranded DNA. Remarkably, this DNA product is efficiently transcribed, generating messenger RNAs that encode a stop codon-less, never-ending ORF (neo) whose translation causes potent growth arrest. Phylogenetic analyses and screening of diverse DRT2 homologs further revealed broad conservation of rolling-circle reverse transcription and Neo protein function. Our work highlights an elegant expansion of genome coding potential through RNA-templated gene creation, and challenges conventional paradigms of genetic information encoded along the one-dimensional axis of genomic DNA.
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Affiliation(s)
- Stephen Tang
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Valentin Conte
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Dennis J. Zhang
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Rimantė Žedaveinytė
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - George D. Lampe
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Tanner Wiegand
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Lauren C. Tang
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Megan Wang
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Matt W.G. Walker
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Jerrin Thomas George
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Luke E. Berchowitz
- Department of Genetics and Development, Columbia University, New York, NY, USA
- Taub Institute for Research on Alzheimer’s and the Aging Brain, New York, NY, USA
| | - Marko Jovanovic
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Samuel H. Sternberg
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
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8
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Ghaly TM, Gillings MR, Rajabal V, Paulsen IT, Tetu SG. Horizontal gene transfer in plant microbiomes: integrons as hotspots for cross-species gene exchange. Front Microbiol 2024; 15:1338026. [PMID: 38741746 PMCID: PMC11089894 DOI: 10.3389/fmicb.2024.1338026] [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: 11/14/2023] [Accepted: 04/08/2024] [Indexed: 05/16/2024] Open
Abstract
Plant microbiomes play important roles in plant health and fitness. Bacterial horizontal gene transfer (HGT) can influence plant health outcomes, driving the spread of both plant growth-promoting and phytopathogenic traits. However, community dynamics, including the range of genetic elements and bacteria involved in this process are still poorly understood. Integrons are genetic elements recently shown to be abundant in plant microbiomes, and are associated with HGT across broad phylogenetic boundaries. They facilitate the spread of gene cassettes, small mobile elements that collectively confer a diverse suite of adaptive functions. Here, we analysed 5,565 plant-associated bacterial genomes to investigate the prevalence and functional diversity of integrons in this niche. We found that integrons are particularly abundant in the genomes of Pseudomonadales, Burkholderiales, and Xanthomonadales. In total, we detected nearly 9,000 gene cassettes, and found that many could be involved in plant growth promotion or phytopathogenicity, suggesting that integrons might play a role in bacterial mutualistic or pathogenic lifestyles. The rhizosphere was enriched in cassettes involved in the transport and metabolism of diverse substrates, suggesting that they may aid in adaptation to this environment, which is rich in root exudates. We also found that integrons facilitate cross-species HGT, which is particularly enhanced in the phyllosphere. This finding may provide an ideal opportunity to promote plant growth by fostering the spread of genes cassettes relevant to leaf health. Together, our findings suggest that integrons are important elements in plant microbiomes that drive HGT, and have the potential to facilitate plant host adaptation.
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Affiliation(s)
- Timothy M. Ghaly
- School of Natural Sciences, Macquarie University, Sydney, NSW, Australia
| | | | - Vaheesan Rajabal
- School of Natural Sciences, Macquarie University, Sydney, NSW, Australia
- ARC Centre of Excellence in Synthetic Biology, Sydney, NSW, Australia
| | - Ian T. Paulsen
- School of Natural Sciences, Macquarie University, Sydney, NSW, Australia
- ARC Centre of Excellence in Synthetic Biology, Sydney, NSW, Australia
| | - Sasha G. Tetu
- School of Natural Sciences, Macquarie University, Sydney, NSW, Australia
- ARC Centre of Excellence in Synthetic Biology, Sydney, NSW, Australia
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9
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Croft LV, Fisher M, Barbhuiya TK, El-Kamand S, Beard S, Rajapakse A, Gamsjaeger R, Cubeddu L, Bolderson E, O'Byrne K, Richard D, Gandhi NS. Sequence- and Structure-Dependent Cytotoxicity of Phosphorothioate and 2'- O-Methyl Modified Single-Stranded Oligonucleotides. Nucleic Acid Ther 2024; 34:143-155. [PMID: 38648015 DOI: 10.1089/nat.2023.0056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024] Open
Abstract
Single-stranded oligonucleotides (SSOs) are a rapidly expanding class of therapeutics that comprises antisense oligonucleotides, microRNAs, and aptamers, with ten clinically approved molecules. Chemical modifications such as the phosphorothioate backbone and the 2'-O-methyl ribose can improve the stability and pharmacokinetic properties of therapeutic SSOs, but they can also lead to toxicity in vitro and in vivo through nonspecific interactions with cellular proteins, gene expression changes, disturbed RNA processing, and changes in nuclear structures and protein distribution. In this study, we screened a mini library of 277 phosphorothioate and 2'-O-methyl-modified SSOs, with or without mRNA complementarity, for cytotoxic properties in two cancer cell lines. Using circular dichroism, nucleic magnetic resonance, and molecular dynamics simulations, we show that phosphorothioate- and 2'-O-methyl-modified SSOs that form stable hairpin structures through Watson-Crick base pairing are more likely to be cytotoxic than those that exist in an extended conformation. In addition, moderate and highly cytotoxic SSOs in our dataset have a higher mean purine composition than pyrimidine. Overall, our study demonstrates a structure-cytotoxicity relationship and indicates that the formation of stable hairpins should be a consideration when designing SSOs toward optimal therapeutic profiles.
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Affiliation(s)
- Laura V Croft
- School of Biomedical Sciences, Centre for Genomics and Personalised Health, Cancer and Ageing Research Program at Translational Research Institute, Faculty of Health, Queensland University of Technology, Brisbane, Australia
| | - Mark Fisher
- School of Biomedical Sciences, Centre for Genomics and Personalised Health, Cancer and Ageing Research Program at Translational Research Institute, Faculty of Health, Queensland University of Technology, Brisbane, Australia
| | - Tabassum Khair Barbhuiya
- School of Chemistry and Physics, Centre for Genomics and Personalised Health, Faculty of Science, Queensland University of Technology, Brisbane, Australia
| | - Serene El-Kamand
- School of Science, Western Sydney University, Penrith, Australia
| | - Samuel Beard
- School of Biomedical Sciences, Centre for Genomics and Personalised Health, Cancer and Ageing Research Program at Translational Research Institute, Faculty of Health, Queensland University of Technology, Brisbane, Australia
| | - Aleksandra Rajapakse
- School of Biomedical Sciences, Centre for Genomics and Personalised Health, Cancer and Ageing Research Program at Translational Research Institute, Faculty of Health, Queensland University of Technology, Brisbane, Australia
| | | | - Liza Cubeddu
- School of Science, Western Sydney University, Penrith, Australia
| | - Emma Bolderson
- School of Biomedical Sciences, Centre for Genomics and Personalised Health, Cancer and Ageing Research Program at Translational Research Institute, Faculty of Health, Queensland University of Technology, Brisbane, Australia
| | - Ken O'Byrne
- School of Biomedical Sciences, Centre for Genomics and Personalised Health, Cancer and Ageing Research Program at Translational Research Institute, Faculty of Health, Queensland University of Technology, Brisbane, Australia
- Princess Alexandra Hospital, Woolloongabba, Australia
| | - Derek Richard
- School of Biomedical Sciences, Centre for Genomics and Personalised Health, Cancer and Ageing Research Program at Translational Research Institute, Faculty of Health, Queensland University of Technology, Brisbane, Australia
| | - Neha S Gandhi
- School of Biomedical Sciences, Centre for Genomics and Personalised Health, Cancer and Ageing Research Program at Translational Research Institute, Faculty of Health, Queensland University of Technology, Brisbane, Australia
- School of Chemistry and Physics, Centre for Genomics and Personalised Health, Faculty of Science, Queensland University of Technology, Brisbane, Australia
- Department of Computer Science and Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Karnataka, India
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10
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de Moura TR, Purta E, Bernat A, Martín-Cuevas E, Kurkowska M, Baulin E, Mukherjee S, Nowak J, Biela A, Rawski M, Glatt S, Moreno-Herrero F, Bujnicki J. Conserved structures and dynamics in 5'-proximal regions of Betacoronavirus RNA genomes. Nucleic Acids Res 2024; 52:3419-3432. [PMID: 38426934 PMCID: PMC11014237 DOI: 10.1093/nar/gkae144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 01/25/2024] [Accepted: 02/26/2024] [Indexed: 03/02/2024] Open
Abstract
Betacoronaviruses are a genus within the Coronaviridae family of RNA viruses. They are capable of infecting vertebrates and causing epidemics as well as global pandemics in humans. Mitigating the threat posed by Betacoronaviruses requires an understanding of their molecular diversity. The development of novel antivirals hinges on understanding the key regulatory elements within the viral RNA genomes, in particular the 5'-proximal region, which is pivotal for viral protein synthesis. Using a combination of cryo-electron microscopy, atomic force microscopy, chemical probing, and computational modeling, we determined the structures of 5'-proximal regions in RNA genomes of Betacoronaviruses from four subgenera: OC43-CoV, SARS-CoV-2, MERS-CoV, and Rousettus bat-CoV. We obtained cryo-electron microscopy maps and determined atomic-resolution models for the stem-loop-5 (SL5) region at the translation start site and found that despite low sequence similarity and variable length of the helical elements it exhibits a remarkable structural conservation. Atomic force microscopy imaging revealed a common domain organization and a dynamic arrangement of structural elements connected with flexible linkers across all four Betacoronavirus subgenera. Together, these results reveal common features of a critical regulatory region shared between different Betacoronavirus RNA genomes, which may allow targeting of these RNAs by broad-spectrum antiviral therapeutics.
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Affiliation(s)
- Tales Rocha de Moura
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, ul. Ks. Trojdena 4, 02-109 Warsaw, Poland
| | - Elżbieta Purta
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, ul. Ks. Trojdena 4, 02-109 Warsaw, Poland
| | - Agata Bernat
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, ul. Ks. Trojdena 4, 02-109 Warsaw, Poland
| | - Eva M Martín-Cuevas
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Małgorzata Kurkowska
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, ul. Ks. Trojdena 4, 02-109 Warsaw, Poland
| | - Eugene F Baulin
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, ul. Ks. Trojdena 4, 02-109 Warsaw, Poland
| | - Sunandan Mukherjee
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, ul. Ks. Trojdena 4, 02-109 Warsaw, Poland
| | - Jakub Nowak
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Artur P Biela
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Michał Rawski
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
- National Synchrotron Radiation Centre SOLARIS, Jagiellonian University, Krakow, Poland
| | - Sebastian Glatt
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Fernando Moreno-Herrero
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Janusz M Bujnicki
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, ul. Ks. Trojdena 4, 02-109 Warsaw, Poland
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11
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Ziesel A, Jabbari H. Unveiling hidden structural patterns in the SARS-CoV-2 genome: Computational insights and comparative analysis. PLoS One 2024; 19:e0298164. [PMID: 38574063 PMCID: PMC10994416 DOI: 10.1371/journal.pone.0298164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 01/19/2024] [Indexed: 04/06/2024] Open
Abstract
SARS-CoV-2, the causative agent of COVID-19, is known to exhibit secondary structures in its 5' and 3' untranslated regions, along with the frameshifting stimulatory element situated between ORF1a and 1b. To identify additional regions containing conserved structures, we utilized a multiple sequence alignment with related coronaviruses as a starting point. We applied a computational pipeline developed for identifying non-coding RNA elements. Our pipeline employed three different RNA structural prediction approaches. We identified forty genomic regions likely to harbor structures, with ten of them showing three-way consensus substructure predictions among our predictive utilities. We conducted intracomparisons of the predictive utilities within the pipeline and intercomparisons with four previously published SARS-CoV-2 structural datasets. While there was limited agreement on the precise structure, different approaches seemed to converge on regions likely to contain structures in the viral genome. By comparing and combining various computational approaches, we can predict regions most likely to form structures, as well as a probable structure or ensemble of structures. These predictions can be used to guide surveillance, prophylactic measures, or therapeutic efforts. Data and scripts employed in this study may be found at https://doi.org/10.5281/zenodo.8298680.
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Affiliation(s)
- Alison Ziesel
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Hosna Jabbari
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
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12
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Yao HT, Marchand B, Berkemer SJ, Ponty Y, Will S. Infrared: a declarative tree decomposition-powered framework for bioinformatics. Algorithms Mol Biol 2024; 19:13. [PMID: 38493130 PMCID: PMC10943887 DOI: 10.1186/s13015-024-00258-2] [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: 09/18/2023] [Accepted: 02/13/2024] [Indexed: 03/18/2024] Open
Abstract
MOTIVATION Many bioinformatics problems can be approached as optimization or controlled sampling tasks, and solved exactly and efficiently using Dynamic Programming (DP). However, such exact methods are typically tailored towards specific settings, complex to develop, and hard to implement and adapt to problem variations. METHODS We introduce the Infrared framework to overcome such hindrances for a large class of problems. Its underlying paradigm is tailored toward problems that can be declaratively formalized as sparse feature networks, a generalization of constraint networks. Classic Boolean constraints specify a search space, consisting of putative solutions whose evaluation is performed through a combination of features. Problems are then solved using generic cluster tree elimination algorithms over a tree decomposition of the feature network. Their overall complexities are linear on the number of variables, and only exponential in the treewidth of the feature network. For sparse feature networks, associated with low to moderate treewidths, these algorithms allow to find optimal solutions, or generate controlled samples, with practical empirical efficiency. RESULTS Implementing these methods, the Infrared software allows Python programmers to rapidly develop exact optimization and sampling applications based on a tree decomposition-based efficient processing. Instead of directly coding specialized algorithms, problems are declaratively modeled as sets of variables over finite domains, whose dependencies are captured by constraints and functions. Such models are then automatically solved by generic DP algorithms. To illustrate the applicability of Infrared in bioinformatics and guide new users, we model and discuss variants of bioinformatics applications. We provide reimplementations and extensions of methods for RNA design, RNA sequence-structure alignment, parsimony-driven inference of ancestral traits in phylogenetic trees/networks, and design of coding sequences. Moreover, we demonstrate multidimensional Boltzmann sampling. These applications of the framework-together with our novel results-underline the practical relevance of Infrared. Remarkably, the achieved complexities are typically equivalent to the ones of specialized algorithms and implementations. AVAILABILITY Infrared is available at https://amibio.gitlabpages.inria.fr/Infrared with extensive documentation, including various usage examples and API reference; it can be installed using Conda or from source.
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Affiliation(s)
- Hua-Ting Yao
- LIX, CNRS UMR 7161, Ecole Polytechnique, Institut Polytechnique de Paris, Palaiseau, France.
- Department of Theoretical Chemistry, University of Vienna, Vienna, Austria.
- School of Computer Science, McGill University, Montreal, Canada.
| | - Bertrand Marchand
- LIX, CNRS UMR 7161, Ecole Polytechnique, Institut Polytechnique de Paris, Palaiseau, France
| | - Sarah J Berkemer
- LIX, CNRS UMR 7161, Ecole Polytechnique, Institut Polytechnique de Paris, Palaiseau, France
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
| | - Yann Ponty
- LIX, CNRS UMR 7161, Ecole Polytechnique, Institut Polytechnique de Paris, Palaiseau, France
| | - Sebastian Will
- LIX, CNRS UMR 7161, Ecole Polytechnique, Institut Polytechnique de Paris, Palaiseau, France.
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13
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Mills J, Gebhard LJ, Schubotz F, Shevchenko A, Speth DR, Liao Y, Duggin IG, Marchfelder A, Erdmann S. Extracellular vesicle formation in Euryarchaeota is driven by a small GTPase. Proc Natl Acad Sci U S A 2024; 121:e2311321121. [PMID: 38408251 DOI: 10.1073/pnas.2311321121] [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: 07/14/2023] [Accepted: 01/14/2024] [Indexed: 02/28/2024] Open
Abstract
Since their discovery, extracellular vesicles (EVs) have changed our view on how organisms interact with their extracellular world. EVs are able to traffic a diverse array of molecules across different species and even domains, facilitating numerous functions. In this study, we investigate EV production in Euryarchaeota, using the model organism Haloferax volcanii. We uncover that EVs enclose RNA, with specific transcripts preferentially enriched, including those with regulatory potential, and conclude that EVs can act as an RNA communication system between haloarchaea. We demonstrate the key role of an EV-associated small GTPase for EV formation in H. volcanii that is also present across other diverse evolutionary branches of Archaea. We propose the name, ArvA, for the identified family of archaeal vesiculating GTPases. Additionally, we show that two genes in the same operon with arvA (arvB and arvC) are also involved in EV formation. Both, arvB and arvC, are closely associated with arvA in the majority of other archaea encoding ArvA. Our work demonstrates that small GTPases involved in membrane deformation and vesiculation, ubiquitous in Eukaryotes, are also present in Archaea and are widely distributed across diverse archaeal phyla.
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Affiliation(s)
- Joshua Mills
- Archaeal Virology, Max Planck Institute for Marine Microbiology, Bremen 28359, Germany
| | - L Johanna Gebhard
- Archaeal Virology, Max Planck Institute for Marine Microbiology, Bremen 28359, Germany
| | - Florence Schubotz
- MARUM Center for Marine Environmental Sciences, University of Bremen, Bremen 28359, Germany
| | - Anna Shevchenko
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany
| | - Daan R Speth
- Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Bremen 28359, Germany
| | - Yan Liao
- The Australian Institute for Microbiology and Infection, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Iain G Duggin
- The Australian Institute for Microbiology and Infection, University of Technology Sydney, Sydney, NSW 2007, Australia
| | | | - Susanne Erdmann
- Archaeal Virology, Max Planck Institute for Marine Microbiology, Bremen 28359, Germany
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14
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Camara MB, Lange B, Yesselman JD, Eichhorn C. Visualizing a two-state conformational ensemble in stem-loop 3 of the transcriptional regulator 7SK RNA. Nucleic Acids Res 2024; 52:940-952. [PMID: 38084902 PMCID: PMC10810284 DOI: 10.1093/nar/gkad1159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 11/15/2023] [Accepted: 11/17/2023] [Indexed: 12/26/2023] Open
Abstract
Structural plasticity is integral to RNA function; however, there are currently few methods to quantitatively resolve RNAs that have multiple structural states. NMR spectroscopy is a powerful approach for resolving conformational ensembles but is size-limited. Chemical probing is well-suited for large RNAs but provides limited structural and kinetics information. Here, we integrate the two approaches to visualize a two-state conformational ensemble for the central stem-loop 3 (SL3) of 7SK RNA, a critical element for 7SK RNA function in transcription regulation. We find that the SL3 distal end exchanges between two equally populated yet structurally distinct states in both isolated SL3 constructs and full-length 7SK RNA. We rationally designed constructs that lock SL3 into a single state and demonstrate that both chemical probing and NMR data fit to a linear combination of the two states. Comparison of vertebrate 7SK RNA sequences shows either or both states are highly conserved. These results provide new insights into 7SK RNA structural dynamics and demonstrate the utility of integrating chemical probing with NMR spectroscopy to gain quantitative insights into RNA conformational ensembles.
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Affiliation(s)
- Momodou B Camara
- Department of Chemistry, University of Nebraska, 639 North 12 St, Lincoln, NE 68588, USA
| | - Bret Lange
- Department of Chemistry, University of Nebraska, 639 North 12 St, Lincoln, NE 68588, USA
| | - Joseph D Yesselman
- Department of Chemistry, University of Nebraska, 639 North 12 St, Lincoln, NE 68588, USA
- Nebraska Center for Integrated Biomolecular Communication, Lincoln, NE, USA
| | - Catherine D Eichhorn
- Department of Chemistry, University of Nebraska, 639 North 12 St, Lincoln, NE 68588, USA
- Nebraska Center for Integrated Biomolecular Communication, Lincoln, NE, USA
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15
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Syska C, Kiers A, Rancurel C, Bailly-Bechet M, Lipuma J, Alloing G, Garcia I, Dupont L. VapC10 toxin of the legume symbiont Sinorhizobium meliloti targets tRNASer and controls intracellular lifestyle. THE ISME JOURNAL 2024; 18:wrae015. [PMID: 38365913 PMCID: PMC10945364 DOI: 10.1093/ismejo/wrae015] [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: 11/08/2023] [Revised: 01/05/2024] [Accepted: 01/25/2024] [Indexed: 02/18/2024]
Abstract
The soil bacterium Sinorhizobium meliloti can establish a nitrogen-fixing symbiosis with the model legume Medicago truncatula. The rhizobia induce the formation of a specialized root organ called nodule, where they differentiate into bacteroids and reduce atmospheric nitrogen into ammonia. Little is known on the mechanisms involved in nodule senescence onset and in bacteroid survival inside the infected plant cells. Although toxin-antitoxin (TA) systems have been shown to promote intracellular survival within host cells in human pathogenic bacteria, their role in symbiotic bacteria was rarely investigated. S. meliloti encodes several TA systems, mainly of the VapBC family. Here we present the functional characterization, through a multidisciplinary approach, of the VapBC10 TA system of S. meliloti. Following a mapping by overexpression of an RNase in Escherichia coli (MORE) RNA-seq analysis, we demonstrated that the VapC10 toxin is an RNase that cleaves the anticodon loop of two tRNASer. Thereafter, a bioinformatics approach was used to predict VapC10 targets in bacteroids. This analysis suggests that toxin activation triggers a specific proteome reprogramming that could limit nitrogen fixation capability and viability of bacteroids. Accordingly, a vapC10 mutant induces a delayed senescence in nodules, associated to an enhanced bacteroid survival. VapBC10 TA system could contribute to S. meliloti adaptation to symbiotic lifestyle, in response to plant nitrogen status.
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Affiliation(s)
- Camille Syska
- Université Côte d'Azur, INRAE, CNRS, Institut Sophia Agrobiotech (ISA), Sophia Antipolis 06903, France
| | - Aurélie Kiers
- Université Côte d'Azur, INRAE, CNRS, Institut Sophia Agrobiotech (ISA), Sophia Antipolis 06903, France
| | - Corinne Rancurel
- Université Côte d'Azur, INRAE, CNRS, Institut Sophia Agrobiotech (ISA), Sophia Antipolis 06903, France
| | - Marc Bailly-Bechet
- Université Côte d'Azur, INRAE, CNRS, Institut Sophia Agrobiotech (ISA), Sophia Antipolis 06903, France
| | | | - Geneviève Alloing
- Université Côte d'Azur, INRAE, CNRS, Institut Sophia Agrobiotech (ISA), Sophia Antipolis 06903, France
| | - Isabelle Garcia
- Université Côte d'Azur, INRAE, CNRS, Institut Sophia Agrobiotech (ISA), Sophia Antipolis 06903, France
| | - Laurence Dupont
- Université Côte d'Azur, INRAE, CNRS, Institut Sophia Agrobiotech (ISA), Sophia Antipolis 06903, France
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16
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Motta LF, Cerrudo CS, Belaich MN. A Comprehensive Study of MicroRNA in Baculoviruses. Int J Mol Sci 2024; 25:603. [PMID: 38203774 PMCID: PMC10778818 DOI: 10.3390/ijms25010603] [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: 11/27/2023] [Revised: 12/19/2023] [Accepted: 12/22/2023] [Indexed: 01/12/2024] Open
Abstract
Baculoviruses are viral pathogens that infect different species of Lepidoptera, Diptera, and Hymenoptera, with a global distribution. Due to their biological characteristics and the biotechnological applications derived from these entities, the Baculoviridae family is an important subject of study and manipulation in the natural sciences. With the advent of RNA interference mechanisms, the presence of baculoviral genes that do not code for proteins but instead generate transcripts similar to microRNAs (miRNAs) has been described. These miRNAs are functionally associated with the regulation of gene expression, both in viral and host sequences. This article provides a comprehensive review of miRNA biogenesis, function, and characterization in general, with a specific focus on those identified in baculoviruses. Furthermore, it delves into the specific roles of baculoviral miRNAs in regulating viral and host genes and presents structural and thermodynamic stability studies that are useful for detecting shared characteristics with predictive utility. This review aims to expand our understanding of the baculoviral miRNAome, contributing to improvements in the production of baculovirus-based biopesticides, management of resistance phenomena in pests, enhancement of recombinant protein production systems, and development of diverse and improved BacMam vectors to meet biomedical demands.
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Affiliation(s)
| | - Carolina Susana Cerrudo
- Laboratorio de Ingeniería Genética y Biología Celular y Molecular—Área Virosis de Insectos, Instituto de Microbiología Básica y Aplicada, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Roque Sáenz Peña 352, Bernal B1876BXD, Buenos Aires, Argentina;
| | - Mariano Nicolás Belaich
- Laboratorio de Ingeniería Genética y Biología Celular y Molecular—Área Virosis de Insectos, Instituto de Microbiología Básica y Aplicada, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Roque Sáenz Peña 352, Bernal B1876BXD, Buenos Aires, Argentina;
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17
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D’Ambrosi S, García-Vílchez R, Kedra D, Vitali P, Macias-Cámara N, Bárcena L, Gonzalez-Lopez M, Aransay AM, Dietmann S, Hurtado A, Blanco S. Global and single-nucleotide resolution detection of 7-methylguanosine in RNA. RNA Biol 2024; 21:1-18. [PMID: 38566310 PMCID: PMC10993922 DOI: 10.1080/15476286.2024.2337493] [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: 03/27/2024] [Indexed: 04/04/2024] Open
Abstract
RNA modifications, including N-7-methylguanosine (m7G), are pivotal in governing RNA stability and gene expression regulation. The accurate detection of internal m7G modifications is of paramount significance, given recent associations between altered m7G deposition and elevated expression of the methyltransferase METTL1 in various human cancers. The development of robust m7G detection techniques has posed a significant challenge in the field of epitranscriptomics. In this study, we introduce two methodologies for the global and accurate identification of m7G modifications in human RNA. We introduce borohydride reduction sequencing (Bo-Seq), which provides base resolution mapping of m7G modifications. Bo-Seq achieves exceptional performance through the optimization of RNA depurination and scission, involving the strategic use of high concentrations of NaBH4, neutral pH and the addition of 7-methylguanosine monophosphate (m7GMP) during the reducing reaction. Notably, compared to NaBH4-based methods, Bo-Seq enhances the m7G detection performance, and simplifies the detection process, eliminating the necessity for intricate chemical steps and reducing the protocol duration. In addition, we present an antibody-based approach, which enables the assessment of m7G relative levels across RNA molecules and biological samples, however it should be used with caution due to limitations associated with variations in antibody quality between batches. In summary, our novel approaches address the pressing need for reliable and accessible methods to detect RNA m7G methylation in human cells. These advancements hold the potential to catalyse future investigations in the critical field of epitranscriptomics, shedding light on the complex regulatory roles of m7G in gene expression and its implications in cancer biology.
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Affiliation(s)
- Silvia D’Ambrosi
- Department of Neurosurgery, Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- CIC bioGUNE, Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Derio, Spain
| | - Raquel García-Vílchez
- Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-University of Salamanca, Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, Salamanca, Spain
| | - Darek Kedra
- Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-University of Salamanca, Salamanca, Spain
| | - Patrice Vitali
- Molecular, Cellular and Developmental Biology unit (MCD), Centre de Biologie Integrative (CBI), University of Toulouse, UPS, CNRS, Toulouse, France
| | - Nuria Macias-Cámara
- CIC bioGUNE, Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Derio, Spain
| | - Laura Bárcena
- CIC bioGUNE, Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Derio, Spain
| | - Monika Gonzalez-Lopez
- CIC bioGUNE, Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Derio, Spain
| | - Ana M. Aransay
- CIC bioGUNE, Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Derio, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Madrid, Spain
| | - Sabine Dietmann
- Department of Developmental Biology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Antonio Hurtado
- Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-University of Salamanca, Salamanca, Spain
| | - Sandra Blanco
- CIC bioGUNE, Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Derio, Spain
- Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-University of Salamanca, Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, Salamanca, Spain
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18
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Backofen R, Gorodkin J, Hofacker IL, Stadler PF. Comparative RNA Genomics. Methods Mol Biol 2024; 2802:347-393. [PMID: 38819565 DOI: 10.1007/978-1-0716-3838-5_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2024]
Abstract
Over the last quarter of a century it has become clear that RNA is much more than just a boring intermediate in protein expression. Ancient RNAs still appear in the core information metabolism and comprise a surprisingly large component in bacterial gene regulation. A common theme with these types of mostly small RNAs is their reliance of conserved secondary structures. Large-scale sequencing projects, on the other hand, have profoundly changed our understanding of eukaryotic genomes. Pervasively transcribed, they give rise to a plethora of large and evolutionarily extremely flexible non-coding RNAs that exert a vastly diverse array of molecule functions. In this chapter we provide a-necessarily incomplete-overview of the current state of comparative analysis of non-coding RNAs, emphasizing computational approaches as a means to gain a global picture of the modern RNA world.
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Affiliation(s)
- Rolf Backofen
- Bioinformatics Group, Department of Computer Science, University of Freiburg, Freiburg, Germany
- Center for Non-coding RNA in Technology and Health, University of Copenhagen, Frederiksberg, Denmark
| | - Jan Gorodkin
- Center for Non-coding RNA in Technology and Health, Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Ivo L Hofacker
- Institute for Theoretical Chemistry, University of Vienna, Wien, Austria
- Bioinformatics and Computational Biology research group, University of Vienna, Vienna, Austria
- Center for Non-coding RNA in Technology and Health, University of Copenhagen, Frederiksberg, Denmark
| | - Peter F Stadler
- Bioinformatics Group, Department of Computer Science, University of Leipzig, Leipzig, Germany.
- Interdisciplinary Center for Bioinformatics, University of Leipzig, Leipzig, Germany.
- Max Planck Institute for Mathematics in the Sciences, Leipzig, Germany.
- Universidad National de Colombia, Bogotá, Colombia.
- Institute for Theoretical Chemistry, University of Vienna, Wien, Austria.
- Center for Non-coding RNA in Technology and Health, University of Copenhagen, Frederiksberg, Denmark.
- Santa Fe Institute, Santa Fe, NM, USA.
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19
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Eggenhofer F, Höner Zu Siederdissen C. Evolutionary Structure Conservation and Covariance Scores. Methods Mol Biol 2024; 2726:255-284. [PMID: 38780735 DOI: 10.1007/978-1-0716-3519-3_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
Effective homology search for non-coding RNAs is frequently not possible via sequence similarity alone. Current methods leverage evolutionary information like structure conservation or covariance scores to identify homologs in organisms that are phylogenetically more distant. In this chapter, we introduce the theoretical background of evolutionary structure conservation and covariance score, and we show hands-on how current methods in the field are applied on example datasets.
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Affiliation(s)
- Florian Eggenhofer
- Bioinformatics Group, Department of Computer Science University of Freiburg, Freiburg, Germany
| | - Christian Höner Zu Siederdissen
- Bioinformatics Group, Department of Computer Science, University of Leipzig, Leipzig, Germany.
- Interdisciplinary Center for Bioinformatics, University of Leipzig, Leipzig, Germany.
- Bioinformatics/High-Throughput Analysis, Faculty of Mathematics and Computer Science, Friedrich Schiller University Jena, Jena, Germany.
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20
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Will S. LocARNA 2.0: Versatile Simultaneous Alignment and Folding of RNAs. Methods Mol Biol 2024; 2726:235-254. [PMID: 38780734 DOI: 10.1007/978-1-0716-3519-3_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
Generating accurate alignments of non-coding RNA sequences is indispensable in the quest for understanding RNA function. Nevertheless, aligning RNAs remains a challenging computational task. In the twilight-zone of RNA sequences with low sequence similarity, sequence homologies and compatible, favorable (a priori unknown) structures can be inferred only in dependency of each other. Thus, simultaneous alignment and folding (SA&F) remains the gold-standard of comparative RNA analysis, even if this method is computationally highly demanding. This text introduces to the recent release 2.0 of the software package LocARNA, focusing on its practical application. The package enables versatile, fast and accurate analysis of multiple RNAs. For this purpose, it implements SA&F algorithms in a specific, lightweight flavor that makes them routinely applicable in large scale. Its high performance is achieved by combining ensemble-based sparsification of the structure space and banding strategies. Probabilistic banding strongly improves the performance of LocARNA 2.0 even over previous releases, while simplifying its effective use. Enabling flexible application to various use cases, LocARNA provides tools to globally and locally compare, cluster, and multiply aligned RNAs based on optimization and probabilistic variants of SA&F, which optionally integrate prior knowledge, expressible by anchor and structure constraints.
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Affiliation(s)
- Sebastian Will
- LIX, CNRS UMR 7161, École Polytechnique, Institut Polytechnique de Paris, Palaiseau, France.
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21
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Wiegand T, Hoffmann FT, Walker MWG, Tang S, Richard E, Le HC, Meers C, Sternberg SH. Emergence of RNA-guided transcription factors via domestication of transposon-encoded TnpB nucleases. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.30.569447. [PMID: 38076855 PMCID: PMC10705468 DOI: 10.1101/2023.11.30.569447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
Transposon-encoded tnpB genes encode RNA-guided DNA nucleases that promote their own selfish spread through targeted DNA cleavage and homologous recombination1-4. This widespread gene family was repeatedly domesticated over evolutionary timescales, leading to the emergence of diverse CRISPR-associated nucleases including Cas9 and Cas125,6. We set out to test the hypothesis that TnpB nucleases may have also been repurposed for novel, unexpected functions other than CRISPR-Cas. Here, using phylogenetics, structural predictions, comparative genomics, and functional assays, we uncover multiple instances of programmable transcription factors that we name TnpB-like nuclease-dead repressors (TldR). These proteins employ naturally occurring guide RNAs to specifically target conserved promoter regions of the genome, leading to potent gene repression in a mechanism akin to CRISPRi technologies invented by humans7. Focusing on a TldR clade found broadly in Enterobacteriaceae, we discover that bacteriophages exploit the combined action of TldR and an adjacently encoded phage gene to alter the expression and composition of the host flagellar assembly, a transformation with the potential to impact motility8, phage susceptibility9, and host immunity10. Collectively, this work showcases the diverse molecular innovations that were enabled through repeated exaptation of genes encoded by transposable elements, and reveals that RNA-guided transcription factors emerged long before the development of dCas9-based editors.
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Affiliation(s)
- Tanner Wiegand
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Florian T Hoffmann
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Matt W G Walker
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Stephen Tang
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Egill Richard
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Hoang C Le
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Chance Meers
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Samuel H Sternberg
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
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22
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Tieng FYF, Abdullah-Zawawi MR, Md Shahri NAA, Mohamed-Hussein ZA, Lee LH, Mutalib NSA. A Hitchhiker's guide to RNA-RNA structure and interaction prediction tools. Brief Bioinform 2023; 25:bbad421. [PMID: 38040490 PMCID: PMC10753535 DOI: 10.1093/bib/bbad421] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/16/2023] [Accepted: 10/26/2023] [Indexed: 12/03/2023] Open
Abstract
RNA biology has risen to prominence after a remarkable discovery of diverse functions of noncoding RNA (ncRNA). Most untranslated transcripts often exert their regulatory functions into RNA-RNA complexes via base pairing with complementary sequences in other RNAs. An interplay between RNAs is essential, as it possesses various functional roles in human cells, including genetic translation, RNA splicing, editing, ribosomal RNA maturation, RNA degradation and the regulation of metabolic pathways/riboswitches. Moreover, the pervasive transcription of the human genome allows for the discovery of novel genomic functions via RNA interactome investigation. The advancement of experimental procedures has resulted in an explosion of documented data, necessitating the development of efficient and precise computational tools and algorithms. This review provides an extensive update on RNA-RNA interaction (RRI) analysis via thermodynamic- and comparative-based RNA secondary structure prediction (RSP) and RNA-RNA interaction prediction (RIP) tools and their general functions. We also highlighted the current knowledge of RRIs and the limitations of RNA interactome mapping via experimental data. Then, the gap between RSP and RIP, the importance of RNA homologues, the relationship between pseudoknots, and RNA folding thermodynamics are discussed. It is hoped that these emerging prediction tools will deepen the understanding of RNA-associated interactions in human diseases and hasten treatment processes.
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Affiliation(s)
- Francis Yew Fu Tieng
- UKM Medical Molecular Biology Institute (UMBI), Universiti Kebangsaan Malaysia (UKM), Kuala Lumpur 56000, Malaysia
| | | | - Nur Alyaa Afifah Md Shahri
- UKM Medical Molecular Biology Institute (UMBI), Universiti Kebangsaan Malaysia (UKM), Kuala Lumpur 56000, Malaysia
| | - Zeti-Azura Mohamed-Hussein
- Institute of Systems Biology (INBIOSIS), UKM, Selangor 43600, Malaysia
- Department of Applied Physics, Faculty of Science and Technology, UKM, Selangor 43600, Malaysia
| | - Learn-Han Lee
- Sunway Microbiomics Centre, School of Medical and Life Sciences, Sunway University, Sunway City 47500, Malaysia
- Novel Bacteria and Drug Discovery Research Group, Microbiome and Bioresource Research Strength, Jeffrey Cheah School of Medicine and Health Sciences, Monash University of Malaysia, Selangor 47500, Malaysia
| | - Nurul-Syakima Ab Mutalib
- UKM Medical Molecular Biology Institute (UMBI), Universiti Kebangsaan Malaysia (UKM), Kuala Lumpur 56000, Malaysia
- Novel Bacteria and Drug Discovery Research Group, Microbiome and Bioresource Research Strength, Jeffrey Cheah School of Medicine and Health Sciences, Monash University of Malaysia, Selangor 47500, Malaysia
- Faculty of Health Sciences, UKM, Kuala Lumpur 50300, Malaysia
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23
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Žedaveinytė R, Meers C, Le HC, Mortman EE, Tang S, Lampe GD, Pesari SR, Gelsinger DR, Wiegand T, Sternberg SH. Antagonistic conflict between transposon-encoded introns and guide RNAs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.20.567912. [PMID: 38045383 PMCID: PMC10690162 DOI: 10.1101/2023.11.20.567912] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
TnpB nucleases represent the evolutionary precursors to CRISPR-Cas12 and are widespread in all domains of life, presumably due to the critical roles they play in transposon proliferation. IS605family TnpB homologs function in bacteria as programmable homing endonucleases by exploiting transposon-encoded guide RNAs to cleave vacant genomic sites, thereby driving transposon maintenance through DSB-stimulated homologous recombination. Whether this pathway is conserved in other genetic contexts, and in association with other transposases, is unknown. Here we uncover molecular mechanisms of transposition and RNA-guided DNA cleavage by IS607-family elements that, remarkably, also encode catalytic, self-splicing group I introns. After reconstituting and systematically investigating each of these biochemical activities for a candidate 'IStron' derived from Clostridium botulinum, we discovered sequence and structural features of the transposon-encoded RNA that satisfy molecular requirements of a group I intron and TnpB guide RNA, while still retaining the ability to be faithfully mobilized at the DNA level by the TnpA transposase. Strikingly, intron splicing was strongly repressed not only by TnpB, but also by the secondary structure of ωRNA alone, allowing the element to carefully control the relative levels of spliced products versus functional guide RNAs. Our results suggest that IStron transcripts have evolved a sensitive equilibrium to balance competing and mutually exclusive activities that promote transposon maintenance while limiting adverse fitness costs on the host. Collectively, this work explains how diverse enzymatic activities emerged during the selfish spread of IS607-family elements and highlights molecular innovation in the multi-functional utility of transposon-encoded noncoding RNAs.
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Affiliation(s)
- Rimantė Žedaveinytė
- Department of Biochemistry and Molecular Biophysics, Columbia University; New York, NY 10032, USA
| | - Chance Meers
- Department of Biochemistry and Molecular Biophysics, Columbia University; New York, NY 10032, USA
| | - Hoang C. Le
- Department of Biochemistry and Molecular Biophysics, Columbia University; New York, NY 10032, USA
| | - Edan E. Mortman
- Department of Genetics and Development, Columbia University; New York, NY 10032, USA
| | - Stephen Tang
- Department of Biochemistry and Molecular Biophysics, Columbia University; New York, NY 10032, USA
| | - George D. Lampe
- Department of Biochemistry and Molecular Biophysics, Columbia University; New York, NY 10032, USA
| | - Sanjana R. Pesari
- Department of Biochemistry and Molecular Biophysics, Columbia University; New York, NY 10032, USA
- Present address: Biochemistry and Molecular Biophysics Program, University of California, San Diego, CA, USA
| | - Diego R. Gelsinger
- Department of Biochemistry and Molecular Biophysics, Columbia University; New York, NY 10032, USA
| | - Tanner Wiegand
- Department of Biochemistry and Molecular Biophysics, Columbia University; New York, NY 10032, USA
| | - Samuel H. Sternberg
- Department of Biochemistry and Molecular Biophysics, Columbia University; New York, NY 10032, USA
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24
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Meers C, Le HC, Pesari SR, Hoffmann FT, Walker MWG, Gezelle J, Tang S, Sternberg SH. Transposon-encoded nucleases use guide RNAs to promote their selfish spread. Nature 2023; 622:863-871. [PMID: 37758954 DOI: 10.1038/s41586-023-06597-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 08/31/2023] [Indexed: 09/29/2023]
Abstract
Insertion sequences are compact and pervasive transposable elements found in bacteria, which encode only the genes necessary for their mobilization and maintenance1. IS200- and IS605-family transposons undergo 'peel-and-paste' transposition catalysed by a TnpA transposase2, but they also encode diverse, TnpB- and IscB-family proteins that are evolutionarily related to the CRISPR-associated effectors Cas12 and Cas9, respectively3,4. Recent studies have demonstrated that TnpB and IscB function as RNA-guided DNA endonucleases5,6, but the broader biological role of this activity has remained enigmatic. Here we show that TnpB and IscB are essential to prevent permanent transposon loss as a consequence of the TnpA transposition mechanism. We selected a family of related insertion sequences from Geobacillus stearothermophilus that encode several TnpB and IscB orthologues, and showed that a single TnpA transposase was broadly active for transposon mobilization. The donor joints formed upon religation of transposon-flanking sequences were efficiently targeted for cleavage by RNA-guided TnpB and IscB nucleases, and co-expression of TnpB and TnpA led to substantially greater transposon retention relative to conditions in which TnpA was expressed alone. Notably, TnpA and TnpB also stimulated recombination frequencies, surpassing rates observed with TnpB alone. Collectively, this study reveals that RNA-guided DNA cleavage arose as a primal biochemical activity to bias the selfish inheritance and spread of transposable elements, which was later co-opted during the evolution of CRISPR-Cas adaptive immunity for antiviral defence.
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Affiliation(s)
- Chance Meers
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Hoang C Le
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Sanjana R Pesari
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
- Biochemistry and Molecular Biophysics Program, University of California, San Diego, CA, USA
| | - Florian T Hoffmann
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Matt W G Walker
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Jeanine Gezelle
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Stephen Tang
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Samuel H Sternberg
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
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25
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Meyer MO, Yamagami R, Choi S, Keating CD, Bevilacqua PC. RNA folding studies inside peptide-rich droplets reveal roles of modified nucleosides at the origin of life. SCIENCE ADVANCES 2023; 9:eadh5152. [PMID: 37729412 PMCID: PMC10511188 DOI: 10.1126/sciadv.adh5152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 08/16/2023] [Indexed: 09/22/2023]
Abstract
Compartmentalization of RNA in biopolymer-rich membraneless organelles is now understood to be pervasive and critical for the function of extant biology and has been proposed as a prebiotically plausible way to accumulate RNA. However, compartment-RNA interactions that drive encapsulation have the potential to influence RNA structure and function in compartment- and RNA sequence-dependent ways. Here, we detail next-generation sequencing (NGS) experiments performed in membraneless compartments called complex coacervates to characterize the fold of many different transfer RNAs (tRNAs) simultaneously under the potentially denaturing conditions of these compartments. Notably, we find that natural modifications favor the native fold of tRNAs in these compartments. This suggests that covalent RNA modifications could have played a critical role in metabolic processes at the origin of life.
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Affiliation(s)
- McCauley O. Meyer
- Department of Biochemistry, Microbiology, and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
- Center for RNA Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Ryota Yamagami
- Center for RNA Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
| | - Saehyun Choi
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
| | - Christine D. Keating
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
| | - Philip C. Bevilacqua
- Department of Biochemistry, Microbiology, and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
- Center for RNA Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, USA
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26
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Ruiz-Ciancio D, Lin LH, Veeramani S, Barros MN, Sanchez D, Di Bartolo AL, Masone D, Giangrande PH, Mestre MB, Thiel WH. Selection of a novel cell-internalizing RNA aptamer specific for CD22 antigen in B cell acute lymphoblastic leukemia. MOLECULAR THERAPY. NUCLEIC ACIDS 2023; 33:698-712. [PMID: 37662970 PMCID: PMC10469072 DOI: 10.1016/j.omtn.2023.07.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 07/25/2023] [Indexed: 09/05/2023]
Abstract
Despite improvements in B cell acute lymphoblastic leukemia (B-ALL) treatment, a significant number of patients experience relapse of the disease, resulting in poor prognosis and high mortality. One of the drawbacks of current B-ALL treatments is the high toxicity associated with the non-specificity of chemotherapeutic drugs. Targeted therapy is an appealing strategy to treat B-ALL to mitigate these toxic off-target effects. One such target is the B cell surface protein CD22. The restricted expression of CD22 on the B-cell lineage and its ligand-induced internalizing properties make it an attractive target in cases of B cell malignancies. To target B-ALL and the CD22 protein, we performed cell internalization SELEX (Systematic Evolution of Ligands by EXponential enrichment) followed by molecular docking to identify internalizing aptamers specific for B-ALL cells that bind the CD22 cell-surface receptor. We identified two RNA aptamers, B-ALL1 and B-ALL2, that target human malignant B cells, with B-ALL1 the first documented RNA aptamer interacting with the CD22 antigen. These B-ALL-specific aptamers represent an important first step toward developing novel targeted therapies for B cell malignancy treatments.
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Affiliation(s)
- Dario Ruiz-Ciancio
- Instituto de Ciencias Biomédicas (ICBM), Facultad de Ciencias Médicas, Universidad Católica de Cuyo, Av. José Ignacio de la Roza 1516, Rivadavia, San Juan 5400, Argentina
- National Council of Scientific and Technical Research (CONICET), Godoy Cruz 2290, Ciudad Autónoma de Buenos Aires C1425FQB, Argentina
| | - Li-Hsien Lin
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52246, USA
| | - Suresh Veeramani
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52246, USA
- Holden Comprehensive Cancer Center, University of Iowa, Iowa City, IA 52242, USA
| | - Maya N. Barros
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52246, USA
| | - Diego Sanchez
- Instituto de Medicina y Biología Experimental de Cuyo (IMBECU), CONICET, CCT-Mendoza 5500, Argentina
| | - Ary Lautaro Di Bartolo
- Instituto de Histología y Embriología de Mendoza (IHEM) – Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Cuyo (UNCuyo), Mendoza M5502JMA, Argentina
| | - Diego Masone
- Instituto de Histología y Embriología de Mendoza (IHEM) – Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional de Cuyo (UNCuyo), Mendoza M5502JMA, Argentina
| | - Paloma H. Giangrande
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52246, USA
- VP Platform Discovery Sciences, Biology, Wave Life Sciences, 733 Concord Avenue, Cambridge, MA 02138, USA
| | - María Belén Mestre
- Instituto de Ciencias Biomédicas (ICBM), Facultad de Ciencias Médicas, Universidad Católica de Cuyo, Av. José Ignacio de la Roza 1516, Rivadavia, San Juan 5400, Argentina
- National Council of Scientific and Technical Research (CONICET), Godoy Cruz 2290, Ciudad Autónoma de Buenos Aires C1425FQB, Argentina
| | - William H. Thiel
- Department of Internal Medicine, University of Iowa, Iowa City, IA 52246, USA
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27
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Jiménez-Gaona Y, Vivanco-Galván O, Cruz D, Armijos-Carrión A, Suárez JP. Compensatory Base Changes in ITS2 Secondary Structure Alignment, Modelling, and Molecular Phylogeny: An Integrated Approach to Improve Species Delimitation in Tulasnella (Basidiomycota). J Fungi (Basel) 2023; 9:894. [PMID: 37755002 PMCID: PMC10532482 DOI: 10.3390/jof9090894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/08/2023] [Accepted: 08/17/2023] [Indexed: 09/28/2023] Open
Abstract
BACKGROUND The delimitation of species of Tulasnella has been extensively studied, mainly at the morphological (sexual and asexual states) and molecular levels-showing ambiguity between them. An integrative species concept that includes characteristics such as molecular, ecology, morphology, and other information is crucial for species delimitation in complex groups such as Tulasnella. OBJECTIVES The aim of this study is to test evolutionary relationships using a combination of alignment-based and alignment-free distance matrices as an alternative molecular tool to traditional methods, and to consider the secondary structures and CBCs from ITS2 (internal transcribed spacer) sequences for species delimitation in Tulasnella. METHODOLOGY Three phylogenetic approaches were plotted: (i) alignment-based, (ii) alignment-free, and (iii) a combination of both distance matrices using the DISTATIS and pvclust libraries from an R package. Finally, the secondary structure consensus was modeled by Mfold, and a CBC analysis was obtained to complement the species delimitation using 4Sale. RESULTS AND CONCLUSIONS The phylogenetic tree results showed delimited monophyletic clades in Tulasnella spp., where all 142 Tulasnella sequences were divided into two main clades A and B and assigned to seven species (T. asymmetrica, T. andina, T. eichleriana ECU6, T. eichleriana ECU4 T. pinicola, T. violea), supported by bootstrap values from 72% to 100%. From the 2D secondary structure alignment, three types of consensus models with helices and loops were obtained. Thus, T. albida belongs to type I; T. eichleriana, T. tomaculum, and T. violea belong to type II; and T. asymmetrica, T. andina, T. pinicola, and T. spp. (GER) belong to type III; each type contains four to six domains, with nine CBCs among these that corroborate different species.
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Affiliation(s)
- Yuliana Jiménez-Gaona
- Departamento de Química, Universidad Técnica Particular de Loja (UTPL), San Cayetano Alto s/n, Loja 1101608, Ecuador
| | - Oscar Vivanco-Galván
- Departamento de Ciencias Biológicas, Universidad Técnica Particular de Loja (UTPL), San Cayetano Alto s/n, Loja 1101608, Ecuador; (O.V.-G.); (D.C.); (J.P.S.)
| | - Darío Cruz
- Departamento de Ciencias Biológicas, Universidad Técnica Particular de Loja (UTPL), San Cayetano Alto s/n, Loja 1101608, Ecuador; (O.V.-G.); (D.C.); (J.P.S.)
| | - Angelo Armijos-Carrión
- Department of Biology, Memorial University of Newfoundland, St. John’s, NL A1B 3X9, Canada;
| | - Juan Pablo Suárez
- Departamento de Ciencias Biológicas, Universidad Técnica Particular de Loja (UTPL), San Cayetano Alto s/n, Loja 1101608, Ecuador; (O.V.-G.); (D.C.); (J.P.S.)
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28
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Salukhe I, Choi R, Van Voorhis W, Barrett L, Hyde J. Regulation of coronavirus nsp15 cleavage specificity by RNA structure. PLoS One 2023; 18:e0290675. [PMID: 37616296 PMCID: PMC10449227 DOI: 10.1371/journal.pone.0290675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 08/13/2023] [Indexed: 08/26/2023] Open
Abstract
SARS-CoV-2, the etiologic agent of the COVID-19 pandemic, has had an enduring impact on global public health. However, SARS-CoV-2 is only one of multiple pathogenic human coronaviruses (CoVs) to have emerged since the turn of the century. CoVs encode for several nonstructural proteins (nsps) that are essential for viral replication and pathogenesis. Among them is nsp15, a uridine-specific viral endonuclease that is important in evading the host immune response and promoting viral replication. Despite the established endonuclease function of nsp15, little is known about other determinants of its cleavage specificity. In this study we investigate the role of RNA secondary structure in SARS-CoV-2 nsp15 endonuclease activity. Using a series of in vitro endonuclease assays, we observed that thermodynamically stable RNA structures were protected from nsp15 cleavage relative to RNAs lacking stable structure. We leveraged the s2m RNA from the SARS-CoV-1 3'UTR as a model for our structural studies as it adopts a well-defined structure with several uridines, two of which are unpaired and thus highly probable targets for nsp15 cleavage. We found that SARS-CoV-2 nsp15 specifically cleaves s2m at the unpaired uridine within the GNRNA pentaloop of the RNA. Further investigation revealed that the position of uridine within the pentaloop also impacted nsp15 cleavage efficiency suggesting that positioning within the pentaloop is necessary for optimal presentation of the scissile uridine and alignment within the nsp15 catalytic pocket. Our findings indicate that RNA secondary structure is an important determinant of nsp15 cleavage and provides insight into the molecular mechanisms of RNA recognition by nsp15.
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Affiliation(s)
- Indraneel Salukhe
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA, United States of America
| | - Ryan Choi
- Division of Allergy and Infectious Diseases, Department of Medicine, Center for Emerging and Reemerging Infectious Diseases (CERID), University of Washington School of Medicine, Seattle, WA, United States of America
| | - Wesley Van Voorhis
- Division of Allergy and Infectious Diseases, Department of Medicine, Center for Emerging and Reemerging Infectious Diseases (CERID), University of Washington School of Medicine, Seattle, WA, United States of America
| | - Lynn Barrett
- Division of Allergy and Infectious Diseases, Department of Medicine, Center for Emerging and Reemerging Infectious Diseases (CERID), University of Washington School of Medicine, Seattle, WA, United States of America
| | - Jennifer Hyde
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA, United States of America
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29
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Camara MB, Lange B, Yesselman JD, Eichhorn CD. Visualizing a two-state conformational ensemble in stem-loop 3 of the transcriptional regulator 7SK RNA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.09.552709. [PMID: 37609139 PMCID: PMC10441402 DOI: 10.1101/2023.08.09.552709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Structural plasticity is integral to RNA function; however, there are currently few methods to quantitatively resolve RNAs that have multiple structural states. NMR spectroscopy is a powerful approach for resolving conformational ensembles but is size-limited. Chemical probing is well-suited for large RNAs but provides limited structural and no kinetics information. Here, we integrate the two approaches to visualize a two-state conformational ensemble for the central stem-loop 3 (SL3) of 7SK RNA, a critical element for 7SK RNA function in transcription regulation. We find that the SL3 distal end exchanges between two equally populated yet structurally distinct states in both isolated SL3 constructs and full-length 7SK RNA. We rationally designed constructs that lock SL3 into a single state and demonstrate that both chemical probing and NMR data fit to a linear combination of the two states. Comparison of vertebrate 7SK RNA sequences shows conservation of both states, suggesting functional importance. These results provide new insights into 7SK RNA structural dynamics and demonstrate the utility of integrating chemical probing with NMR spectroscopy to gain quantitative insights into RNA conformational ensembles.
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Affiliation(s)
- Momodou B. Camara
- Department of Chemistry, University of Nebraska, 639 North 12th St, Lincoln, NE 68588, USA
| | - Bret Lange
- Department of Chemistry, University of Nebraska, 639 North 12th St, Lincoln, NE 68588, USA
| | - Joseph D. Yesselman
- Department of Chemistry, University of Nebraska, 639 North 12th St, Lincoln, NE 68588, USA
- Nebraska Center for Integrated Biomolecular Communication
| | - Catherine D. Eichhorn
- Department of Chemistry, University of Nebraska, 639 North 12th St, Lincoln, NE 68588, USA
- Nebraska Center for Integrated Biomolecular Communication
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30
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Vanden Broeck A, Klinge S. Principles of human pre-60 S biogenesis. Science 2023; 381:eadh3892. [PMID: 37410842 DOI: 10.1126/science.adh3892] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 05/20/2023] [Indexed: 07/08/2023]
Abstract
During the early stages of human large ribosomal subunit (60S) biogenesis, an ensemble of assembly factors establishes and fine-tunes the essential RNA functional centers of pre-60S particles by an unknown mechanism. Here, we report a series of cryo-electron microscopy structures of human nucleolar and nuclear pre-60S assembly intermediates at resolutions of 2.5 to 3.2 angstroms. These structures show how protein interaction hubs tether assembly factor complexes to nucleolar particles and how guanosine triphosphatases and adenosine triphosphatase couple irreversible nucleotide hydrolysis steps to the installation of functional centers. Nuclear stages highlight how a conserved RNA-processing complex, the rixosome, couples large-scale RNA conformational changes with pre-ribosomal RNA processing by the RNA degradation machinery. Our ensemble of human pre-60S particles provides a rich foundation with which to elucidate the molecular principles of ribosome formation.
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Affiliation(s)
- Arnaud Vanden Broeck
- Laboratory of Protein and Nucleic Acid Chemistry, The Rockefeller University, New York, NY 10065, USA
| | - Sebastian Klinge
- Laboratory of Protein and Nucleic Acid Chemistry, The Rockefeller University, New York, NY 10065, USA
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31
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Warner BR, Bundschuh R, Fredrick K. Roles of the leader-trailer helix and antitermination complex in biogenesis of the 30S ribosomal subunit. Nucleic Acids Res 2023; 51:5242-5254. [PMID: 37102690 PMCID: PMC10250234 DOI: 10.1093/nar/gkad316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 04/07/2023] [Accepted: 04/13/2023] [Indexed: 04/28/2023] Open
Abstract
Ribosome biogenesis occurs co-transcriptionally and entails rRNA folding, ribosomal protein binding, rRNA processing, and rRNA modification. In most bacteria, the 16S, 23S and 5S rRNAs are co-transcribed, often with one or more tRNAs. Transcription involves a modified RNA polymerase, called the antitermination complex, which forms in response to cis-acting elements (boxB, boxA and boxC) in the nascent pre-rRNA. Sequences flanking the rRNAs are complementary and form long helices known as leader-trailer helices. Here, we employed an orthogonal translation system to interrogate the functional roles of these RNA elements in 30S subunit biogenesis in Escherichia coli. Mutations that disrupt the leader-trailer helix caused complete loss of translation activity, indicating that this helix is absolutely essential for active subunit formation in the cell. Mutations of boxA also reduced translation activity, but by only 2- to 3-fold, suggesting a smaller role for the antitermination complex. Similarly modest drops in activity were seen upon deletion of either or both of two leader helices, termed here hA and hB. Interestingly, subunits formed in the absence of these leader features exhibited defects in translational fidelity. These data suggest that the antitermination complex and precursor RNA elements help to ensure quality control during ribosome biogenesis.
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Affiliation(s)
- Benjamin R Warner
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
- Center for RNA Biology, 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 and 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
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH 43210, USA
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Lasher B, Hendrix DA. bpRNA-align: improved RNA secondary structure global alignment for comparing and clustering RNA structures. RNA (NEW YORK, N.Y.) 2023; 29:584-595. [PMID: 36759128 PMCID: PMC10159002 DOI: 10.1261/rna.079211.122] [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: 04/20/2022] [Accepted: 01/14/2023] [Indexed: 05/06/2023]
Abstract
Ribonucleic acid (RNA) is a polymeric molecule that is fundamental to biological processes, with structure being more highly conserved than primary sequence and often key to its function. Advances in RNA structure characterization have resulted in an increase in the number of accurate secondary structures. The task of uncovering common RNA structural motifs with a collective function through structural comparison, providing a level of similarity, remains challenging and could be used to improve RNA secondary structure databases and discover new RNA families. In this work, we present a novel secondary structure alignment method, bpRNA-align. bpRNA-align is a customized global structural alignment method, utilizing an inverted (gap extend costs more than gap open) and context-specific affine gap penalty along with a structural, feature-specific substitution matrix to provide similarity scores. We evaluate our similarity scores in comparison to other methods, using affinity propagation clustering, applied to a benchmarking data set of known structure types. bpRNA-align shows improvement in clustering performance over a broad range of structure types.
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Affiliation(s)
- Brittany Lasher
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, USA
| | - David A Hendrix
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, USA
- School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, Oregon 97331, USA
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Sudhakar S, Barkau CL, Chilamkurthy R, Barber HM, Pater AA, Moran SD, Damha MJ, Pradeepkumar PI, Gagnon KT. Binding to the conserved and stably folded guide RNA pseudoknot induces Cas12a conformational changes during ribonucleoprotein assembly. J Biol Chem 2023; 299:104700. [PMID: 37059184 PMCID: PMC10200996 DOI: 10.1016/j.jbc.2023.104700] [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: 09/19/2022] [Revised: 04/05/2023] [Accepted: 04/07/2023] [Indexed: 04/16/2023] Open
Abstract
Ribonucleoproteins (RNPs) comprise one or more RNA and protein molecules that interact to form a stable complex, which commonly involves conformational changes in the more flexible RNA components. Here, we propose that Cas12a RNP assembly with its cognate CRISPR RNA (crRNA) guide instead proceeds primarily through Cas12a conformational changes during binding to more stable, prefolded crRNA 5' pseudoknot handles. Phylogenetic reconstructions and sequence and structure alignments revealed that the Cas12a proteins are divergent in sequence and structure while the crRNA 5' repeat region, which folds into a pseudoknot and anchors binding to Cas12a, is highly conserved. Molecular dynamics simulations of three Cas12a proteins and their cognate guides revealed substantial flexibility for unbound apo-Cas12a. In contrast, crRNA 5' pseudoknots were predicted to be stable and independently folded. Limited trypsin hydrolysis, differential scanning fluorimetry, thermal denaturation, and CD analyses supported conformational changes of Cas12a during RNP assembly and an independently folded crRNA 5' pseudoknot. This RNP assembly mechanism may be rationalized by evolutionary pressure to conserve CRISPR loci repeat sequence, and therefore guide RNA structure, to maintain function across all phases of the CRISPR defense mechanism.
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Affiliation(s)
- Sruthi Sudhakar
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, India
| | - Christopher L Barkau
- Department of Biochemistry and Molecular Biology, School of Medicine, Southern Illinois University, Carbondale, Illinois, USA
| | - Ramadevi Chilamkurthy
- Department of Biochemistry and Molecular Biology, School of Medicine, Southern Illinois University, Carbondale, Illinois, USA
| | - Halle M Barber
- Department of Chemistry, McGill University, Montreal, Quebec, Canada
| | - Adrian A Pater
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois, USA
| | - Sean D Moran
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois, USA
| | - Masad J Damha
- Department of Chemistry, McGill University, Montreal, Quebec, Canada
| | - P I Pradeepkumar
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, India.
| | - Keith T Gagnon
- Department of Biochemistry and Molecular Biology, School of Medicine, Southern Illinois University, Carbondale, Illinois, USA; Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois, USA.
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Sass AM, Coenye T. The Small RNA NcS25 Regulates Biological Amine-Transporting Outer Membrane Porin BCAL3473 in Burkholderia cenocepacia. mSphere 2023; 8:e0008323. [PMID: 36971554 PMCID: PMC10117139 DOI: 10.1128/msphere.00083-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 03/03/2023] [Indexed: 03/29/2023] Open
Abstract
Regulation of porin expression in bacteria is complex and often involves small-RNA regulators. Several small-RNA regulators have been described for Burkholderia cenocepacia, and this study aimed to characterize the biological role of the conserved small RNA NcS25 and its cognate target, outer membrane protein BCAL3473. The B. cenocepacia genome carries a large number of genes encoding porins with yet-uncharacterized functions. Expression of the porin BCAL3473 is strongly repressed by NcS25 and activated by other factors, such as a LysR-type regulator and nitrogen-depleted growth conditions. The porin is involved in transport of arginine, tyrosine, tyramine, and putrescine across the outer membrane. Porin BCAL3473, with NcS25 as a major regulator, plays an important role in the nitrogen metabolism of B. cenocepacia. IMPORTANCE Burkholderia cenocepacia is a Gram-negative bacterium which causes infections in immunocompromised individuals and in people with cystic fibrosis. A low outer membrane permeability is one of the factors giving it a high level of innate resistance to antibiotics. Porins provide selective permeability for nutrients, and antibiotics can also traverse the outer membrane by this means. Knowing the properties and specificities of porin channels is therefore important for understanding resistance mechanisms and for developing new antibiotics and could help in overcoming permeability issues in antibiotic treatment.
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Affiliation(s)
- Andrea M. Sass
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ghent, Belgium
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Qiu X. Sequence similarity governs generalizability of de novo deep learning models for RNA secondary structure prediction. PLoS Comput Biol 2023; 19:e1011047. [PMID: 37068100 PMCID: PMC10138783 DOI: 10.1371/journal.pcbi.1011047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 04/27/2023] [Accepted: 03/25/2023] [Indexed: 04/18/2023] Open
Abstract
Making no use of physical laws or co-evolutionary information, de novo deep learning (DL) models for RNA secondary structure prediction have achieved far superior performances than traditional algorithms. However, their statistical underpinning raises the crucial question of generalizability. We present a quantitative study of the performance and generalizability of a series of de novo DL models, with a minimal two-module architecture and no post-processing, under varied similarities between seen and unseen sequences. Our models demonstrate excellent expressive capacities and outperform existing methods on common benchmark datasets. However, model generalizability, i.e., the performance gap between the seen and unseen sets, degrades rapidly as the sequence similarity decreases. The same trends are observed from several recent DL and machine learning models. And an inverse correlation between performance and generalizability is revealed collectively across all learning-based models with wide-ranging architectures and sizes. We further quantitate how generalizability depends on sequence and structure identity scores via pairwise alignment, providing unique quantitative insights into the limitations of statistical learning. Generalizability thus poses a major hurdle for deploying de novo DL models in practice and various pathways for future advances are discussed.
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Affiliation(s)
- Xiangyun Qiu
- Department of Physics, George Washington University, Washington DC, United States of America
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Litov AG, Okhezin EV, Kholodilov IS, Belova OA, Karganova GG. Conserved Sequences in the 5' and 3' Untranslated Regions of Jingmenvirus Group Representatives. Viruses 2023; 15:v15040971. [PMID: 37112951 PMCID: PMC10141212 DOI: 10.3390/v15040971] [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: 03/07/2023] [Revised: 04/10/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
The Jingmenvirus group (JVG), with members such as Jingmen tick virus (JMTV), Alongshan virus (ALSV), Yanggou tick virus (YGTV), and Takachi virus (TAKV), is drawing attention due to evidence of it causing disease in humans and its unique genome architecture. In the current work, complete untranslated regions (UTRs) of four strains of ALSV and eight strains of YGTV were obtained. An analysis of these sequences, as well as JVG sequences from GenBank, uncovered several regions within viral UTRs that were highly conserved for all the segments and viruses. Bioinformatics predictions suggested that the UTRs of all the segments of YGTV, ALSV, and JMTV could form similar RNA structures. The most notable feature of these structures was a stable stem-loop with one (5' UTR) or two (3' UTR) AAGU tetraloops on the end of a hairpin.
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Affiliation(s)
- Alexander G Litov
- Laboratory of Biology of Arboviruses, FSASI "Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of RAS" (Institute of Poliomyelitis), 108819 Moscow, Russia
| | - Egor V Okhezin
- Laboratory of Biology of Arboviruses, FSASI "Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of RAS" (Institute of Poliomyelitis), 108819 Moscow, Russia
- Department of Biology, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Ivan S Kholodilov
- Laboratory of Biology of Arboviruses, FSASI "Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of RAS" (Institute of Poliomyelitis), 108819 Moscow, Russia
| | - Oxana A Belova
- Laboratory of Biology of Arboviruses, FSASI "Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of RAS" (Institute of Poliomyelitis), 108819 Moscow, Russia
| | - Galina G Karganova
- Laboratory of Biology of Arboviruses, FSASI "Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of RAS" (Institute of Poliomyelitis), 108819 Moscow, Russia
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Meers C, Le H, Pesari SR, Hoffmann FT, Walker MW, Gezelle J, Sternberg SH. Transposon-encoded nucleases use guide RNAs to selfishly bias their inheritance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.14.532601. [PMID: 36993599 PMCID: PMC10055086 DOI: 10.1101/2023.03.14.532601] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Insertion sequences (IS) are compact and pervasive transposable elements found in bacteria, which encode only the genes necessary for their mobilization and maintenance. IS 200 /IS 605 elements undergo 'peel-and-paste' transposition catalyzed by a TnpA transposase, but intriguingly, they also encode diverse, TnpB- and IscB-family proteins that are evolutionarily related to the CRISPR-associated effectors Cas12 and Cas9, respectively. Recent studies demonstrated that TnpB-family enzymes function as RNA-guided DNA endonucleases, but the broader biological role of this activity has remained enigmatic. Here we show that TnpB/IscB are essential to prevent permanent transposon loss as a consequence of the TnpA transposition mechanism. We selected a family of related IS elements from Geobacillus stearothermophilus that encode diverse TnpB/IscB orthologs, and showed that a single TnpA transposase was active for transposon excision. The donor joints formed upon religation of IS-flanking sequences were efficiently targeted for cleavage by RNA-guided TnpB/IscB nucleases, and co-expression of TnpB together with TnpA led to significantly greater transposon retention, relative to conditions in which TnpA was expressed alone. Remarkably, TnpA and TnpB/IscB recognize the same AT-rich transposon-adjacent motif (TAM) during transposon excision and RNA-guided DNA cleavage, respectively, revealing a striking convergence in the evolution of DNA sequence specificity between collaborating transposase and nuclease proteins. Collectively, our study reveals that RNA-guided DNA cleavage is a primal biochemical activity that arose to bias the selfish inheritance and spread of transposable elements, which was later co-opted during the evolution of CRISPR-Cas adaptive immunity for antiviral defense.
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Affiliation(s)
- Chance Meers
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY
| | - Hoang Le
- Department of Biology, University of Pennsylvania, Philadelphia, PA
| | - Sanjana R. Pesari
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY
| | - Florian T. Hoffmann
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY
| | - Matt W.G. Walker
- Department of Biological Sciences, Columbia University, New York, NY
| | - Jeanine Gezelle
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY
| | - Samuel H. Sternberg
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY
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Sabei A, Caldas Baia TG, Saffar R, Martin J, Frezza E. Internal Normal Mode Analysis Applied to RNA Flexibility and Conformational Changes. J Chem Inf Model 2023; 63:2554-2572. [PMID: 36972178 DOI: 10.1021/acs.jcim.2c01509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
We investigated the capability of internal normal modes to reproduce RNA flexibility and predict observed RNA conformational changes and, notably, those induced by the formation of RNA-protein and RNA-ligand complexes. Here, we extended our iNMA approach developed for proteins to study RNA molecules using a simplified representation of the RNA structure and its potential energy. Three data sets were also created to investigate different aspects. Despite all the approximations, our study shows that iNMA is a suitable method to take into account RNA flexibility and describe its conformational changes opening the route to its applicability in any integrative approach where these properties are crucial.
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Broeck AV, Klinge S. Principles of human pre-60 S biogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.14.532478. [PMID: 36993238 PMCID: PMC10054963 DOI: 10.1101/2023.03.14.532478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
During early stages of human large ribosomal subunit (60 S ) biogenesis, an ensemble of assembly factors establishes and fine-tunes the essential RNA functional centers of pre-60 S particles by an unknown mechanism. Here, we report a series of cryo-electron microscopy structures of human nucleolar and nuclear pre-60 S assembly intermediates at resolutions of 2.5-3.2 Ã…. These structures show how protein interaction hubs tether assembly factor complexes to nucleolar particles and how GTPases and ATPases couple irreversible nucleotide hydrolysis steps to the installation of functional centers. Nuclear stages highlight how a conserved RNA processing complex, the rixosome, couples large-scale RNA conformational changes to pre-rRNA processing by the RNA degradation machinery. Our ensemble of human pre-60 S particles provides a rich foundation to elucidate the molecular principles of ribosome formation. One-Sentence Summary High-resolution cryo-EM structures of human pre-60S particles reveal new principles of eukaryotic ribosome assembly.
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40
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Tan XY, Citartan M, Chinni SV, Ahmed SA, Tang TH. Biocomputational Identification of sRNAs in Leptospira interrogans Serovar Lai. Indian J Microbiol 2023; 63:33-41. [PMID: 37188232 PMCID: PMC10172424 DOI: 10.1007/s12088-022-01050-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 12/02/2022] [Indexed: 12/24/2022] Open
Abstract
Regulatory small RNAs (sRNA) are RNA transcripts that are not translated into proteins but act as functional RNAs. Pathogenic Leptospira cause an epidemic spirochaetal zoonosis, Leptospirosis. It is speculated that Leptospiral sRNAs are involved in orchestrating their pathogenicity. In this study, biocomputational approach was adopted to identify Leptospiral sRNAs. In this study, two sRNA prediction programs, i.e., RNAz and nocoRNAc, were employed to screen the reference genome of Leptospira interrogans serovar Lai. Out of 126 predicted sRNAs, there are 96 cis-antisense sRNAs, 28 trans-encoded sRNAs and 2 sRNAs that partially overlap with protein-coding genes in a sense orientation. To determine whether these candidates are expressed in the pathogen, they were compared with the coverage files generated from our RNA-seq datasets. It was found out that 7 predicted sRNAs are expressed in mid-log phase, stationary phase, serum stress, temperature stress and iron stress while 2 sRNAs are expressed in mid-log phase, stationary phase, serum stress, and temperature stress. Besides, their expressions were also confirmed experimentally via RT-PCR. These experimentally validated candidates were also subjected to mRNA target prediction using TargetRNA2. Taken together, our study demonstrated that biocomputational strategy can serve as an alternative or as a complementary strategy to the laborious and expensive deep sequencing methods not only to uncover putative sRNAs but also to predict their targets in bacteria. In fact, this is the first study that integrates computational approach to predict putative sRNAs in L. interrogans serovar Lai. Supplementary Information The online version contains supplementary material available at 10.1007/s12088-022-01050-9.
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Affiliation(s)
- Xinq Yuan Tan
- Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200 Kepala Batas, Penang Malaysia
| | - Marimuthu Citartan
- Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200 Kepala Batas, Penang Malaysia
| | - Suresh Venkata Chinni
- Department of Biotechnology, Faculty of Applied Sciences, AIMST University, 08100 Bedong, Kedah Malaysia
| | - Siti Aminah Ahmed
- Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200 Kepala Batas, Penang Malaysia
| | - Thean-Hock Tang
- Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200 Kepala Batas, Penang Malaysia
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41
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Meyer MO, Yamagami R, Choi S, Keating CD, Bevilacqua PC. RNA folding studies inside peptide-rich droplets reveal roles of modified nucleosides at the origin of life. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.27.530264. [PMID: 36909509 PMCID: PMC10002651 DOI: 10.1101/2023.02.27.530264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Compartmentalization of RNA in biopolymer-rich membraneless organelles is now understood to be pervasive and critical for the function of extant biology and has been proposed as a prebiotically-plausible way to accumulate RNA. However, compartment-RNA interactions that drive encapsulation have the potential to influence RNA structure and function in compartment- and RNA sequence-dependent ways. Herein, we detail Next-Generation Sequencing (NGS) experiments performed for the first time in membraneless compartments called complex coacervates to characterize the fold of many different transfer RNAs (tRNAs) simultaneously under the potentially denaturing conditions of these compartments. Strikingly, we find that natural modifications favor the native fold of tRNAs in these compartments. This suggests that covalent RNA modifications could have played a critical role in metabolic processes at the origin of life. One Sentence Summary We demonstrate that RNA folds into native secondary and tertiary structures in protocell models and that this is favored by covalent modifications, which is critical for the origins of life.
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Bokolia NP, Gadepalli R. Identification of consensus hairpin loop structure among the negative sense subgenomic RNAs of SARS-CoV-2. BULLETIN OF THE NATIONAL RESEARCH CENTRE 2023; 47:28. [PMID: 36852284 PMCID: PMC9947893 DOI: 10.1186/s42269-023-01002-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND SARS-CoV-2 is the causative agent of worldwide pandemic disease coronavirus disease 19. SARS-CoV-2 bears positive sense RNA genome that has organized and complex pattern of replication/transcription process including the generation of subgenomic RNAs. Transcription regulatory sequences have important role in the pausing of replication/transcription and generation of subgenomic RNAs. RESULTS In the present bioinformatics analysis, a consensus secondary structure was identified among negative sense subgenomic RNAs of SARS-CoV-2. This consensus region is present at the adjacent of initiation codon. CONCLUSIONS This study proposed that consensus structured domain could involve in mediating the long pausing of replication/transcription complex and responsible for subgenomic RNA production. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1186/s42269-023-01002-3.
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Affiliation(s)
- Naveen Prakash Bokolia
- Viral Research and Diagnostic Laboratory, Microbiology Department, All India Institute of Medical Sciences, Jodhpur, 342001 India
| | - Ravisekhar Gadepalli
- Viral Research and Diagnostic Laboratory, Microbiology Department, All India Institute of Medical Sciences, Jodhpur, 342001 India
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Levi O, Mallik M, Arava YS. ThrRS-Mediated Translation Regulation of the RNA Polymerase III Subunit RPC10 Occurs through an Element with Similarity to Cognate tRNA ASL and Affects tRNA Levels. Genes (Basel) 2023; 14:462. [PMID: 36833389 PMCID: PMC9956033 DOI: 10.3390/genes14020462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 02/08/2023] [Accepted: 02/09/2023] [Indexed: 02/15/2023] Open
Abstract
Aminoacyl tRNA synthetases (aaRSs) are a well-studied family of enzymes with a canonical role in charging tRNAs with a specific amino acid. These proteins appear to also have non-canonical roles, including post-transcriptional regulation of mRNA expression. Many aaRSs were found to bind mRNAs and regulate their translation into proteins. However, the mRNA targets, mechanism of interaction, and regulatory consequences of this binding are not fully resolved. Here, we focused on yeast cytosolic threonine tRNA synthetase (ThrRS) to decipher its impact on mRNA binding. Affinity purification of ThrRS with its associated mRNAs followed by transcriptome analysis revealed a preference for mRNAs encoding RNA polymerase subunits. An mRNA that was significantly bound compared to all others was the mRNA encoding RPC10, a small subunit of RNA polymerase III. Structural modeling suggested that this mRNA includes a stem-loop element that is similar to the anti-codon stem loop (ASL) structure of ThrRS cognate tRNA (tRNAThr). We introduced random mutations within this element and found that almost every change from the normal sequence leads to reduced binding by ThrRS. Furthermore, point mutations at six key positions that abolish the predicted ASL-like structure showed a significant decrease in ThrRS binding with a decrease in RPC10 protein levels. Concomitantly, tRNAThr levels were reduced in the mutated strain. These data suggest a novel regulatory mechanism in which cellular tRNA levels are regulated through a mimicking element within an RNA polymerase III subunit in a manner that involves the tRNA cognate aaRS.
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Affiliation(s)
| | | | - Yoav S. Arava
- Faculty of Biology, Technion—Israel Institute of Technology, Haifa 3200003, Israel
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44
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Hollar A, Bursey H, Jabbari H. Pseudoknots in RNA Structure Prediction. Curr Protoc 2023; 3:e661. [PMID: 36779804 DOI: 10.1002/cpz1.661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
RNA molecules play active roles in the cell and are important for numerous applications in biotechnology and medicine. The function of an RNA molecule stems from its structure. RNA structure determination is time consuming, challenging, and expensive using experimental methods. Thus, much research has been directed at RNA structure prediction through computational means. Many of these methods focus primarily on the secondary structure of the molecule, ignoring the possibility of pseudoknotted structures. However, pseudoknots are known to play functional roles in many RNA molecules or in their method of interaction with other molecules. Improving the accuracy and efficiency of computational methods that predict pseudoknots is an ongoing challenge for single RNA molecules, RNA-RNA interactions, and RNA-protein interactions. To improve the accuracy of prediction, many methods focus on specific applications while restricting the length and the class of the pseudoknotted structures they can identify. In recent years, computational methods for structure prediction have begun to catch up with the impressive developments seen in biotechnology. Here, we provide a non-comprehensive overview of available pseudoknot prediction methods and their best-use cases. © 2023 Wiley Periodicals LLC.
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Affiliation(s)
- Andrew Hollar
- Department of Computer Science, University of Victoria, Victoria, Canada
| | - Hunter Bursey
- Department of Computer Science, University of Victoria, Victoria, Canada
| | - Hosna Jabbari
- Department of Computer Science, University of Victoria, Victoria, Canada
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45
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Genome-Wide RNA Secondary Structure Prediction. Methods Mol Biol 2023; 2586:35-48. [PMID: 36705897 DOI: 10.1007/978-1-0716-2768-6_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The information of RNA secondary structure has been widely applied to the inference of RNA function. However, a classical prediction method is not feasible to long RNAs such as mRNA due to the problems of computational time and numerical errors. To overcome those problems, sliding window methods have been applied while their results are not directly comparable to global RNA structure prediction. In this chapter, we introduce ParasoR, a method designed for parallel computation of genome-wide RNA secondary structures. To enable genome-wide prediction, ParasoR distributes dynamic programming (DP) matrices required for structure prediction to multiple computational nodes. Using the database of not the original DP variable but the ratio of variables, ParasoR can locally compute the structure scores such as stem probability or accessibility on demand. A comprehensive analysis of local secondary structures by ParasoR is expected to be a promising way to detect the statistical constraints on long RNAs.
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Jagodnik J, Tjaden B, Ross W, Gourse R. Identification and characterization of RNA binding sites for (p)ppGpp using RNA-DRaCALA. Nucleic Acids Res 2023; 51:852-869. [PMID: 36617997 PMCID: PMC9881157 DOI: 10.1093/nar/gkac1224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 11/30/2022] [Accepted: 01/04/2023] [Indexed: 01/10/2023] Open
Abstract
Ligand-binding RNAs (RNA aptamers) are widespread in the three domains of life, serving as sensors of metabolites and other small molecules. When aptamers are embedded within RNA transcripts as components of riboswitches, they can regulate gene expression upon binding their ligands. Previous methods for biochemical validation of computationally predicted aptamers are not well-suited for rapid screening of large numbers of RNA aptamers. Therefore, we utilized DRaCALA (Differential Radial Capillary Action of Ligand Assay), a technique designed originally to study protein-ligand interactions, to examine RNA-ligand binding, permitting rapid screening of dozens of RNA aptamer candidates concurrently. Using this method, which we call RNA-DRaCALA, we screened 30 ykkC family subtype 2a RNA aptamers that were computationally predicted to bind (p)ppGpp. Most of the aptamers bound both ppGpp and pppGpp, but some strongly favored only ppGpp or pppGpp, and some bound neither. Expansion of the number of biochemically verified sites allowed construction of more accurate secondary structure models and prediction of key features in the aptamers that distinguish a ppGpp from a pppGpp binding site. To demonstrate that the method works with other ligands, we also used RNA DRaCALA to analyze aptamer binding by thiamine pyrophosphate.
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Affiliation(s)
- Jonathan Jagodnik
- Department of Bacteriology, University of Wisconsin–Madison, Madison, WI 53706, USA
| | - Brian Tjaden
- Department of Computer Science, Wellesley College, Wellesley, MA 02481, USA
| | - Wilma Ross
- Department of Bacteriology, University of Wisconsin–Madison, Madison, WI 53706, USA
| | - Richard L Gourse
- Department of Bacteriology, University of Wisconsin–Madison, Madison, WI 53706, USA
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Mötz M, Stadler J, Kreutzmann H, Ladinig A, Lamp B, Auer A, Riedel C, Rümenapf T. A Conserved Stem-Loop Structure within ORF5 Is a Frequent Recombination Hotspot for Porcine Reproductive and Respiratory Syndrome Virus 1 (PRRSV-1) with a Particular Modified Live Virus (MLV) Strain. Viruses 2023; 15:258. [PMID: 36680298 PMCID: PMC9867337 DOI: 10.3390/v15010258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/09/2023] [Accepted: 01/13/2023] [Indexed: 01/18/2023] Open
Abstract
The emergence of recombinant PRRSV strains has been observed for more than a decade. These recombinant viruses are characterized by a genome that contains genetic material from at least two different parental strains. Due to the advanced sequencing techniques and a growing number of data bank entries, the role of PRRSV recombinants has become increasingly important since they are sometimes associated with clinical outbreaks. Chimeric viruses observed more recently are products of PRRSV wild-type and vaccine strains. Here, we report on three PRRSV-1 isolates from geographically distant farms with differing clinical manifestations. A sequencing and recombination analysis revealed that these strains are crossovers between different wild-type strains and the same modified live virus vaccine strain. Interestingly, the recombination breakpoint of all analyzed isolates appears at the beginning of open reading frame 5 (ORF5). RNA structure predictions indicate a conserved stem loop in close proximity to the recombination hotspot, which is a plausible cause of a polymerase template switch during RNA replication. Further research into the mechanisms of the stem loop is needed to help understand the PRRSV recombination process and the role of MLVs as parental strains.
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Affiliation(s)
- Marlene Mötz
- Institute of Virology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210 Vienna, Austria
| | - Julia Stadler
- Clinic for Swine, Center for Clinical Veterinary Medicine, Faculty of Veterinary Medicine, Ludwig-Maximilians-University Munich, Sonnenstrasse 16, 85764 Oberschleissenheim, Germany
| | - Heinrich Kreutzmann
- Clinic for Swine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210 Vienna, Austria
| | - Andrea Ladinig
- Clinic for Swine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210 Vienna, Austria
| | - Benjamin Lamp
- Institute of Virology, Department of Veterinary Medicine, Justus-Liebig-University Giessen, Schubertstraße 81, 35392 Giessen, Germany
| | - Angelika Auer
- Institute of Virology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210 Vienna, Austria
| | - Christiane Riedel
- Département de Biologie, École Nationale Supérieure de Lyon, 46 Allée d’Italie, 69364 Lyon, France
- Centre International de Recherche en Infectiologie (CIRI), 46 Allée d’Italie, 69364 Lyon, France
| | - Till Rümenapf
- Institute of Virology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinaerplatz 1, 1210 Vienna, Austria
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48
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Ghaly TM, Tetu SG, Penesyan A, Qi Q, Rajabal V, Gillings MR. Discovery of integrons in Archaea: Platforms for cross-domain gene transfer. SCIENCE ADVANCES 2022; 8:eabq6376. [PMID: 36383678 PMCID: PMC9668308 DOI: 10.1126/sciadv.abq6376] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 10/19/2022] [Indexed: 06/16/2023]
Abstract
Horizontal gene transfer between different domains of life is increasingly being recognized as an important evolutionary driver, with the potential to increase the pace of biochemical innovation and environmental adaptation. However, the mechanisms underlying the recruitment of exogenous genes from foreign domains are mostly unknown. Integrons are a family of genetic elements that facilitate this process within Bacteria. However, they have not been reported outside Bacteria, and thus their potential role in cross-domain gene transfer has not been investigated. Here, we discover that integrons are also present in 75 archaeal metagenome-assembled genomes from nine phyla, and are particularly enriched among Asgard archaea. Furthermore, we provide experimental evidence that integrons can facilitate the recruitment of archaeal genes by bacteria. Our findings establish a previously unknown mechanism of cross-domain gene transfer whereby bacteria can incorporate archaeal genes from their surrounding environment via integron activity. These findings have important implications for prokaryotic ecology and evolution.
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Affiliation(s)
- Timothy M. Ghaly
- School of Natural Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Sasha G. Tetu
- School of Natural Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Anahit Penesyan
- School of Natural Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Qin Qi
- School of Natural Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Vaheesan Rajabal
- School of Natural Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Michael R. Gillings
- School of Natural Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales 2109, Australia
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49
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Juříčková I, Hudec M, Votava F, Vosáhlo J, Ovsepian SV, Černá M, O’Leary VB. The Immunological Epigenetic Landscape of the Human Life Trajectory. Biomedicines 2022; 10:biomedicines10112894. [PMID: 36428462 PMCID: PMC9687906 DOI: 10.3390/biomedicines10112894] [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: 10/07/2022] [Revised: 10/26/2022] [Accepted: 11/08/2022] [Indexed: 11/16/2022] Open
Abstract
Adaptive immunity changes over an individual’s lifetime, maturing by adulthood and diminishing with old age. Epigenetic mechanisms involving DNA and histone methylation form the molecular basis of immunological memory during lymphocyte development. Monocytes alter their function to convey immune tolerance, yet the epigenetic influences at play remain to be fully understood in the context of lifespan. This study of a healthy genetically homogenous cohort of children, adults and seniors sought to decipher the epigenetic dynamics in B-lymphocytes and monocytes. Variable global cytosine methylation within retro-transposable LINE-1 repeats was noted in monocytes compared to B-lymphocytes across age groups. The expression of the human leukocyte antigen (HLA)-DQ alpha chain gene HLA-DQA1*01 revealed significantly reduced levels in monocytes in all ages relative to B-lymphocytes, as well as between lifespan groups. High melting point analysis and bisulfite sequencing of the HLA-DQA1*01 promoter in monocytes highlighted variable cytosine methylation in children and seniors but greater stability at this locus in adults. Further epigenetic evaluation revealed higher histone lysine 27 trimethylation in monocytes from this adult group. Chromatin immunoprecipitation and RNA pulldown demonstrated association with a novel lncRNA TINA with structurally conserved similarities to the previously recognized epigenetic modifier PARTICLE. Seeking to interpret the epigenetic immunological landscape across three representative age groups, this study focused on HLA-DQA1*01 to expose cytosine and histone methylation alterations and their association with the non-coding transcriptome. Such insights unveil previously unknown complex epigenetic layers, orchestrating the strength and weakening of adaptive immunity with the progression of life.
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Affiliation(s)
- Iva Juříčková
- Department of Medical Genetics, Third Faculty of Medicine, Charles University, Vinohrady, 10000 Prague, Czech Republic
- Correspondence: (I.J.); (V.B.O.)
| | - Michael Hudec
- Department of Medical Genetics, Third Faculty of Medicine, Charles University, Vinohrady, 10000 Prague, Czech Republic
| | - Felix Votava
- Department of Children and Adolescents, Third Faculty of Medicine, Charles University, Vinohrady, 10000 Prague, Czech Republic
- Královské Vinohrady University Hospital, Vinohrady, 10034 Prague, Czech Republic
| | - Jan Vosáhlo
- Department of Children and Adolescents, Third Faculty of Medicine, Charles University, Vinohrady, 10000 Prague, Czech Republic
- Královské Vinohrady University Hospital, Vinohrady, 10034 Prague, Czech Republic
| | - Saak Victor Ovsepian
- Faculty of Engineering and Science, University of Greenwich London, Chatham Maritime, Kent ME4 4TB, UK
| | - Marie Černá
- Department of Medical Genetics, Third Faculty of Medicine, Charles University, Vinohrady, 10000 Prague, Czech Republic
| | - Valerie Bríd O’Leary
- Department of Medical Genetics, Third Faculty of Medicine, Charles University, Vinohrady, 10000 Prague, Czech Republic
- Correspondence: (I.J.); (V.B.O.)
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50
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Biesiada M, Hu MY, Williams LD, Purzycka KJ, Petrov AS. rRNA expansion segment 7 in eukaryotes: from Signature Fold to tentacles. Nucleic Acids Res 2022; 50:10717-10732. [PMID: 36200812 PMCID: PMC9561286 DOI: 10.1093/nar/gkac844] [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: 12/27/2021] [Revised: 09/13/2022] [Accepted: 09/22/2022] [Indexed: 11/14/2022] Open
Abstract
The ribosomal core is universally conserved across the tree of life. However, eukaryotic ribosomes contain diverse rRNA expansion segments (ESs) on their surfaces. Sites of ES insertions are predicted from sites of insertion of micro-ESs in archaea. Expansion segment 7 (ES7) is one of the most diverse regions of the ribosome, emanating from a short stem loop and ranging to over 750 nucleotides in mammals. We present secondary and full-atom 3D structures of ES7 from species spanning eukaryotic diversity. Our results are based on experimental 3D structures, the accretion model of ribosomal evolution, phylogenetic relationships, multiple sequence alignments, RNA folding algorithms and 3D modeling by RNAComposer. ES7 contains a distinct motif, the 'ES7 Signature Fold', which is generally invariant in 2D topology and 3D structure in all eukaryotic ribosomes. We establish a model in which ES7 developed over evolution through a series of elementary and recursive growth events. The data are sufficient to support an atomic-level accretion path for rRNA growth. The non-monophyletic distribution of some ES7 features across the phylogeny suggests acquisition via convergent processes. And finally, illustrating the power of our approach, we constructed the 2D and 3D structure of the entire LSU rRNA of Mus musculus.
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Affiliation(s)
- Marcin Biesiada
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan 61-704, Poland
| | - Michael Y Hu
- Center for the Origins of Life, Georgia Institute of Technology, Atlanta, GA 30332, USA.,School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Loren Dean Williams
- Center for the Origins of Life, Georgia Institute of Technology, Atlanta, GA 30332, USA.,School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Katarzyna J Purzycka
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan 61-704, Poland
| | - Anton S Petrov
- Center for the Origins of Life, Georgia Institute of Technology, Atlanta, GA 30332, USA.,School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA
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