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He W, Zhang X, Zou Y, Li J, Chang L, He YC, Jin Q, Ye J. Effective synthesis of circRNA via a thermostable T7 RNA polymerase variant as the catalyst. Front Bioeng Biotechnol 2024; 12:1356354. [PMID: 38655387 PMCID: PMC11035883 DOI: 10.3389/fbioe.2024.1356354] [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: 12/15/2023] [Accepted: 03/04/2024] [Indexed: 04/26/2024] Open
Abstract
Introduction Circular RNAs (circRNAs) are endogenous noncoding RNAs (ncRNAs) with transcriptional lengths ranging from hundreds to thousands. circRNAs have attracted attention owing to their stable structure and ability to treat complicated diseases. Our objective was to create a one-step reaction for circRNA synthesis using wild-type T7 RNA polymerase as the catalyst. However, T7 RNA polymerase is thermally unstable, and we streamlined circRNA synthesis via consensus and folding free energy calculations for hotspot selection. Because of the thermal instability, the permuted intron and exon (PIE) method for circRNA synthesis is conducted via tandem catalysis with a transcription reaction at a low temperature and linear RNA precursor cyclization at a high temperature. Methods To streamline the process, a multisite mutant T7 RNA polymerase (S430P, N433T, S633P, F849I, F880Y, and G788A) with significantly improved thermostability was constructed, and G788A was used. Results The resulting mutant exhibited stable activity at 45°C for over an hour, enabling the implementation of a one-pot transcription and cyclization reaction. The simplified circRNA production process demonstrated an efficiency comparable to that of the conventional two-step reaction, with a cyclization rate exceeding 95% and reduced production of immunostimulatory dsRNA byproducts.
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Affiliation(s)
- Wei He
- College of Biology and the Environment, Nanjing Forestry University, Nanjing, China
- Vazyme Biotech Co., Ltd, Nanjing, China
| | | | | | - Ji Li
- Vazyme Biotech Co., Ltd, Nanjing, China
| | - Le Chang
- Vazyme Biotech Co., Ltd, Nanjing, China
| | - Yu-Cai He
- School of Pharmacy, Changzhou University, Changzhou, China
| | | | - Jianren Ye
- College of Biology and the Environment, Nanjing Forestry University, Nanjing, China
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2
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Zhang Q, Zhao S, Su C, Han Q, Han Y, Tian X, Li Y, Zhang CY. Construction of a Quantum-Dot-Based FRET Nanosensor through Direct Encoding of Streptavidin-Binding RNA Aptamers for N6-Methyladenosine Demethylase Detection. Anal Chem 2023; 95:13201-13210. [PMID: 37603851 DOI: 10.1021/acs.analchem.3c02149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
N6-Methyladenosine (m6A) demethylases can catalyze the removal of the methyl modification on m6A, and it is closely associated with the occurrence, proliferation, differentiation, and metastasis of malignancies. The m6A demethylases (e.g., fat mass and obesity-associated protein (FTO)) may act as a cancer biomarker and are crucial for anticancer drug screening and early clinical diagnosis. Herein, we demonstrate the construction of a quantum-dot-based Förster resonance energy-transfer (FRET) nanosensor through direct encoding of streptavidin-binding RNA aptamers (SA aptamers) for m6A demethylase detection. This nanosensor employs multiple Cy5-molecule-labeled SA aptamers as the building materials to construct the 605QD-RNA-Cy5 nanoassembly, and it exploits the hinder effect of m6A upon elongation and ligation reactions to distinguish m6A-containing RNA probes from demethylated RNA probes. When m6A demethylase is present, the m6A-containing RNA probes are demethylated to generate the demethylated RNA probes, initiating strand extension and ligation reactions to yield a complete transcription template for SA aptamers. Subsequently, a T7-assisted cascade transcription amplification reaction is activated to transcribe abundant SA aptamers with the incorporation of multiple Cy5 fluorophores. The Cy5-incorporated SA aptamers can self-assembly onto the streptavidin-coated 605QD surface to obtain the 605QD-SA aptamer-Cy5 nanoassemblies, resulting in the generation of distinct FRET signals. This nanosensor exhibits ultrahigh sensitivity and excellent specificity, and it can detect endogenous FTO at the single-cell level. Furthermore, this nanosensor can precisely measure enzyme kinetic parameters, screen m6A demethylase inhibitors, and differentiate the FTO expression between breast cancer patients and healthy individual tissues, offering a versatile platform for clinical diagnostic and drug discovery.
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Affiliation(s)
- Qian Zhang
- College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, China
| | - Shuangnan Zhao
- College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, China
| | - Cong Su
- College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, China
| | - Qian Han
- School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Yun Han
- School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Xiaorui Tian
- College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, China
| | - Yueying Li
- Henan Institute of Medical and Pharmaceutical Sciences & BGI College, Zhengzhou University, Zhengzhou 450052, China
| | - Chun-Yang Zhang
- College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, China
- School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
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3
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Xue Y, Li J, Chen D, Zhao X, Hong L, Liu Y. Observation of structural switch in nascent SAM-VI riboswitch during transcription at single-nucleotide and single-molecule resolution. Nat Commun 2023; 14:2320. [PMID: 37087479 PMCID: PMC10122661 DOI: 10.1038/s41467-023-38042-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 04/13/2023] [Indexed: 04/24/2023] Open
Abstract
Growing RNAs fold differently as they are transcribed, which modulates their finally adopted structures. Riboswitches regulate gene expression by structural change, which are sensitive to co-transcriptionally structural biology. Here we develop a strategy to track the structural change of RNAs during transcription at single-nucleotide and single-molecule resolution and use it to monitor individual transcripts of the SAM-VI riboswitch (riboSAM) as transcription proceeds, observing co-existence of five states in riboSAM. We report a bifurcated helix in one newly identified state from NMR and single-molecule FRET (smFRET) results, and its presence directs the translation inhibition in our cellular translation experiments. A model is proposed to illustrate the distinct switch patterns and gene-regulatory outcome of riboSAM when SAM is present or absent. Our strategy enables the precise mapping of RNAs' conformational landscape during transcription, and may combine with detection methods other than smFRET for structural studies of RNAs in general.
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Affiliation(s)
- Yanyan Xue
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jun Li
- School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Dian Chen
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xizhu Zhao
- Zhiyuan College, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Liang Hong
- School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China.
- Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai, 200240, China.
- Shanghai Artificial Intelligence Laboratory, Shanghai, 200232, China.
| | - Yu Liu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
- Shanghai Artificial Intelligence Laboratory, Shanghai, 200232, China.
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4
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Dousis A, Ravichandran K, Hobert EM, Moore MJ, Rabideau AE. An engineered T7 RNA polymerase that produces mRNA free of immunostimulatory byproducts. Nat Biotechnol 2023; 41:560-568. [PMID: 36357718 PMCID: PMC10110463 DOI: 10.1038/s41587-022-01525-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 09/22/2022] [Indexed: 11/12/2022]
Abstract
In vitro transcription (IVT) is a DNA-templated process for synthesizing long RNA transcripts, including messenger RNA (mRNA). For many research and commercial applications, IVT of mRNA is typically performed using bacteriophage T7 RNA polymerase (T7 RNAP) owing to its ability to produce full-length RNA transcripts with high fidelity; however, T7 RNAP can also produce immunostimulatory byproducts such as double-stranded RNA that can affect protein expression. Such byproducts require complex purification processes, using methods such as reversed-phase high-performance liquid chromatography, to yield safe and effective mRNA-based medicines. To minimize the need for downstream purification processes, we rationally and computationally engineered a double mutant of T7 RNAP that produces substantially less immunostimulatory RNA during IVT compared with wild-type T7 RNAP. The resulting mutant allows for a simplified production process with similar mRNA potency, lower immunostimulatory content and quicker manufacturing time compared with wild-type T7 RNAP. Herein, we describe the computational design and development of this improved T7 RNAP variant.
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Affiliation(s)
- Athanasios Dousis
- Moderna, Inc., Cambridge, MA, USA
- Tessera Therapeutics, Somerville, MA, USA
| | | | - Elissa M Hobert
- Moderna, Inc., Cambridge, MA, USA
- Laronde, Cambridge, MA, USA
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5
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Rubalcava-Gracia D, García-Villegas R, Larsson NG. No role for nuclear transcription regulators in mammalian mitochondria? Mol Cell 2023; 83:832-842. [PMID: 36182692 DOI: 10.1016/j.molcel.2022.09.010] [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: 06/20/2022] [Revised: 08/17/2022] [Accepted: 09/08/2022] [Indexed: 10/14/2022]
Abstract
Although the mammalian mtDNA transcription machinery is simple and resembles bacteriophage systems, there are many reports that nuclear transcription regulators, as exemplified by MEF2D, MOF, PGC-1α, and hormone receptors, are imported into mammalian mitochondria and directly interact with the mtDNA transcription machinery. However, the supporting experimental evidence for this concept is open to alternate interpretations, and a main issue is the difficulty in distinguishing indirect regulation of mtDNA transcription, caused by altered nuclear gene expression, from direct intramitochondrial effects. We provide a critical discussion and experimental guidelines to stringently assess roles of intramitochondrial factors implicated in direct regulation of mammalian mtDNA transcription.
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Affiliation(s)
- Diana Rubalcava-Gracia
- Division of Molecular Metabolism, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Rodolfo García-Villegas
- Division of Molecular Metabolism, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Nils-Göran Larsson
- Division of Molecular Metabolism, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
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6
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Wang LJ, Lv MM, Hu JP, Liu M, Zhang CY. Proximity ligation-transcription circuit-powered exponential amplifications for single-molecule monitoring of telomerase in human cells. Chem Commun (Camb) 2023; 59:1181-1184. [PMID: 36628652 DOI: 10.1039/d2cc06087f] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We develop a new strategy for single-molecule monitoring of telomerase based on proximity ligation-transcription circuit-powered exponential amplifications. This strategy exhibits high sensitivity with a detection limit of 0.1 aM for the synthetic telomerase product TPC4 in vitro and 1 HeLa cell in vivo. Moreover, it can screen potential inhibitors, discriminate telomerase from interferents, and distinguish cancer cells from normal cells.
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Affiliation(s)
- Li-Juan Wang
- College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, China. .,School of Chemistry and Chemical Engineering, Southeast University, Nanjing, 211189, China
| | - Meng-Meng Lv
- College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, China.
| | - Jin-Ping Hu
- School of Chemistry and Chemical Engineering, Southeast University, Nanjing, 211189, China
| | - Meng Liu
- College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, China.
| | - Chun-Yang Zhang
- College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, China.
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7
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Johnson RS, Strausbauch M, McCloud C. An NTP-driven mechanism for the nucleotide addition cycle of Escherichia coli RNA polymerase during transcription. PLoS One 2022; 17:e0273746. [PMID: 36282801 PMCID: PMC9595533 DOI: 10.1371/journal.pone.0273746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 08/15/2022] [Indexed: 11/06/2022] Open
Abstract
The elementary steps of transcription as catalyzed by E. coli RNA polymerase during one and two rounds of the nucleotide addition cycle (NAC) were resolved in rapid kinetic studies. Modelling of stopped-flow kinetic data of pyrophosphate release in a coupled enzyme assay during one round of the NAC indicates that the rate of pyrophosphate release is significantly less than that for nucleotide incorporation. Upon modelling of the stopped-flow kinetic data for pyrophosphate release during two rounds of the NAC, it was observed that the presence of the next nucleotide for incorporation increases the rate of release of the first pyrophosphate equivalent; incorrect nucleotides for incorporation had no effect on the rate of pyrophosphate release. Although the next nucleotide for incorporation increases the rate of pyrophosphate release, it is still significantly less than the rate of incorporation of the first nucleotide. The results from the stopped-flow kinetic studies were confirmed by using quench-flow followed by thin-layer chromatography (QF-TLC) with only the first nucleotide for incorporation labeled on the gamma phosphate with 32P to monitor pyrophosphate release. Collectively, the results are consistent with an NTP-driven model for the NAC in which the binding of the next cognate nucleotide for incorporation causes a synergistic conformational change in the enzyme that triggers the more rapid release of pyrophosphate, translocation of the enzyme along the DNA template strand and nucleotide incorporation.
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Affiliation(s)
- Ronald S. Johnson
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
- * E-mail:
| | - Mark Strausbauch
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| | - Christopher McCloud
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
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8
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Zhang Y, Du XK, Liu WJ, Liu M, Zhang CY. Programmable Ligation-Transcription Circuit-Driven Cascade Amplification Machinery for Multiple Long Noncoding RNAs Detection in Lung Tissues. Anal Chem 2022; 94:10573-10578. [PMID: 35867839 DOI: 10.1021/acs.analchem.2c02685] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The measurement of long noncoding RNAs (lncRNAs) is essential to diagnosis and treatment of various diseases such as cancers. Herein, we develop a simple method to simultaneously detect multiple lncRNAs using programmable ligation-transcription circuit-driven cascade amplification and single-molecule counting. The presence of targets lncRNA HOTAIR and lncRNA MALAT1 activates the ligation-transcription circuits to produce two corresponding functional RNAs. The functional RNAs then cyclically initiate the digestion of signal probes by duplex-specific nuclease to liberate Cy5 and Cy3 molecules. After magnetic separation, the liberated Cy5 and Cy3 molecules are measured by single-molecule counting. In this assay, a single lncRNA can activate ligation-transcription circuit to generate abundant functional RNAs, endowing this assay with high sensitivity. Integration of single-molecule counting ensures the high sensitivity. This method shows extremely high sensitivity with a limit of detection (LOD) of 0.043 aM for HOX gene antisense intergenic RNA (lncRNA HOTAIR) and 0.126 aM for mammalian metastasis-related lung adenocarcinoma transcript 1 (lncRNA MALAT1). Importantly, this method enables simultaneous measurement of multiple endogenous lncRNAs at the single-cell level, and it may discriminate the expressions of various lncRNA in lung tumor tissues of nonsmall cell lung cancer (NSCLC) patients and their corresponding healthy adjacent tissues, offering a promising platform for clinical diagnosis and biomedical research.
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Affiliation(s)
- Yan Zhang
- College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, China.,College of Chemistry and Chemical Engineering, Qilu Normal University, Jinan 250200, China
| | - Xue-Ke Du
- College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, China
| | - Wen-Jing Liu
- School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China
| | - Meng Liu
- College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, China
| | - Chun-Yang Zhang
- College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, China
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9
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Li Z, Wang W, Ma B, Yin J, Hu C, Luo P, Wang Y. Genomic and biological characteristics of a newly isolated lytic bacteriophage PZJ0206 infecting the Enterobacter cloacae. Virus Res 2022; 316:198800. [DOI: 10.1016/j.virusres.2022.198800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 04/26/2022] [Accepted: 05/06/2022] [Indexed: 10/18/2022]
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10
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Simple synthesis of massively parallel RNA microarrays via enzymatic conversion from DNA microarrays. Nat Commun 2022; 13:3772. [PMID: 35773271 PMCID: PMC9246885 DOI: 10.1038/s41467-022-31370-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 06/14/2022] [Indexed: 11/20/2022] Open
Abstract
RNA catalytic and binding interactions with proteins and small molecules are fundamental elements of cellular life processes as well as the basis for RNA therapeutics and molecular engineering. In the absence of quantitative predictive capacity for such bioaffinity interactions, high throughput experimental approaches are needed to sufficiently sample RNA sequence space. Here we report on a simple and highly accessible approach to convert commercially available customized DNA microarrays of any complexity and density to RNA microarrays via a T7 RNA polymerase-mediated extension of photocrosslinked methyl RNA primers and subsequent degradation of the DNA templates. RNA microarrays have many potential applications, but are difficult to produce. Here, the AUs present a method for converting commercial, customizable DNA microarrays into RNA microarrays using an accessible three-step process involving primer photocrosslinking, extension, and template degradation.
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11
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Scherr MJ, Wahab SA, Remus D, Duderstadt KE. Mobile origin-licensing factors confer resistance to conflicts with RNA polymerase. Cell Rep 2022; 38:110531. [PMID: 35320708 PMCID: PMC8961423 DOI: 10.1016/j.celrep.2022.110531] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 12/10/2021] [Accepted: 02/23/2022] [Indexed: 12/30/2022] Open
Abstract
Fundamental to our understanding of chromosome duplication is the idea that replication origins function both as sites where MCM helicases are loaded during the G1 phase and where synthesis begins in S phase. However, the temporal delay between phases exposes the replisome assembly pathway to potential disruption prior to replication. Using multicolor, single-molecule imaging, we systematically study the consequences of encounters between actively transcribing RNA polymerases (RNAPs) and replication initiation intermediates in the context of chromatin. We demonstrate that RNAP can push multiple licensed MCM helicases over long distances with nucleosomes ejected or displaced. Unexpectedly, we observe that MCM helicase loading intermediates also can be repositioned by RNAP and continue origin licensing after encounters with RNAP, providing a web of alternative origin specification pathways. Taken together, our observations reveal a surprising mobility in origin-licensing factors that confers resistance to the complex challenges posed by diverse obstacles encountered on chromosomes. RNA polymerase robustly pushes MCMs without slowing down Nucleosomes are ejected or pushed by MCMs during repositioning RNA polymerase can bypass ORC or activate ORC sliding and OCCM sliding Origin licensing continues after RNA polymerase encounters and relocalization
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Affiliation(s)
- Matthias J Scherr
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Syafiq Abd Wahab
- Memorial Sloan Kettering Cancer Center, Molecular Biology Program, 1275 York Avenue, New York, NY 10065, USA
| | - Dirk Remus
- Memorial Sloan Kettering Cancer Center, Molecular Biology Program, 1275 York Avenue, New York, NY 10065, USA
| | - Karl E Duderstadt
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany; Physik Department, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany.
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12
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Wang S, Chen D, Gao L, Liu Y. Short Oligonucleotides Facilitate Co-transcriptional Labeling of RNA at Specific Positions. J Am Chem Soc 2022; 144:5494-5502. [PMID: 35293210 DOI: 10.1021/jacs.2c00020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Labeling RNA molecules at specific positions is critical for RNA research and applications. Such methods are in high demand but still a challenge, especially those that enable native co-synthesis rather than post-synthesis labeling of long RNAs. The method we developed in this work meets these requirements, in which a leader RNA is extended on the hybrid solid-liquid phase by an engineered transcriptional complex following the pause-restart mode. A custom-designed short oligonucleotide is used to functionalize the engineered complex. This remarkable co-transcriptional labeling method incorporates labels into RNAs in high yields with great flexibility. We demonstrate the method by successfully introducing natural modifications, a fluorescent nucleotide analogue and a donor-acceptor fluorophore pair to specific sites located at an internal loop, a pseudoknot, a junction, a helix, and the middle of consecutive identical nucleotides of various RNAs. This newly developed method overcomes efficiency and position-choosing constraints that have hampered routine strategies to label RNAs beyond 200 nucleotides (nt).
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Affiliation(s)
- Siyu Wang
- State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Dian Chen
- State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Lingzhi Gao
- State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yu Liu
- State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.,Shanghai Artificial Intelligence Laboratory, Shanghai 200232, China
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13
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Wang J, Shi Y, Reiss K, Allen B, Maschietto F, Lolis E, Konigsberg WH, Lisi GP, Batista VS. Insights into Binding of Single-Stranded Viral RNA Template to the Replication-Transcription Complex of SARS-CoV-2 for the Priming Reaction from Molecular Dynamics Simulations. Biochemistry 2022; 61:424-432. [PMID: 35199520 PMCID: PMC8887646 DOI: 10.1021/acs.biochem.1c00755] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 02/09/2022] [Indexed: 01/18/2023]
Abstract
A minimal replication-transcription complex (RTC) of SARS-CoV-2 for synthesis of viral RNAs includes the nsp12 RNA-dependent RNA polymerase and two nsp8 RNA primase subunits for de novo primer synthesis, one nsp8 in complex with its accessory nsp7 subunit and the other without it. The RTC is responsible for faithfully copying the entire (+) sense viral genome from its first 5'-end to the last 3'-end nucleotides through a replication-intermediate (RI) template. The single-stranded (ss) RNA template for the RI is its 33-nucleotide 3'-poly(A) tail adjacent to a well-characterized secondary structure. The ssRNA template for viral transcription is a 5'-UUUAU-3' next to stem-loop (SL) 1'. We analyze the electrostatic potential distribution of the nsp8 subunit within the RTC around the template strand of the primer/template (P/T) RNA duplex in recently published cryo-EM structures to address the priming reaction using the viral poly(A) template. We carried out molecular dynamics (MD) simulations with a P/T RNA duplex, the viral poly(A) template, or a generic ssRNA template. We find evidence that the viral poly(A) template binds similarly to the template strand of the P/T RNA duplex within the RTC, mainly through electrostatic interactions, providing new insights into the priming reaction by the nsp8 subunit within the RTC, which differs significantly from the existing proposal of the nsp7/nsp8 oligomer formed outside the RTC. High-order oligomerization of nsp8 and nsp7 for SARS-CoV observed outside the RTC of SARS-CoV-2 is not found in the RTC and not likely to be relevant to the priming reaction.
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Affiliation(s)
- Jimin Wang
- Department of Molecular Biophysics and Biochemistry,
Yale University, New Haven, Connecticut 06520-8114,
United States
| | - Yuanjun Shi
- Department of Chemistry, Yale
University, New Haven, Connecticut 06511-8499, United
States
| | - Krystle Reiss
- Department of Chemistry, Yale
University, New Haven, Connecticut 06511-8499, United
States
| | - Brandon Allen
- Department of Chemistry, Yale
University, New Haven, Connecticut 06511-8499, United
States
| | - Federica Maschietto
- Department of Chemistry, Yale
University, New Haven, Connecticut 06511-8499, United
States
| | - Elias Lolis
- Department of Pharmacology, Yale
University, New Haven, Connecticut 06520-8066, United
States
| | - William H. Konigsberg
- Department of Molecular Biophysics and Biochemistry,
Yale University, New Haven, Connecticut 06520-8114,
United States
| | - George P. Lisi
- Department of Molecular and Cell Biology and
Biochemistry, Brown University, Providence, Rhode Island 02912,
United States
| | - Victor S. Batista
- Department of Chemistry, Yale
University, New Haven, Connecticut 06511-8499, United
States
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14
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Zhang P, Fischer A, Ouyang Y, Wang J, Sohn YS, Karmi O, Nechushtai R, Willner I. Biocatalytic cascades and intercommunicated biocatalytic cascades in microcapsule systems. Chem Sci 2022; 13:7437-7448. [PMID: 35872834 PMCID: PMC9241983 DOI: 10.1039/d2sc01542k] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 04/29/2022] [Indexed: 12/13/2022] Open
Abstract
Dynamic dimerization of GOx-loaded microcapsules with β-gal//hemin/G-quadruplex-bridged T1/T2-loaded microcapsules guides the bi-directional intercommunication of the three catalysts cascade.
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Affiliation(s)
- Pu Zhang
- Institute of Chemistry, Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
- Key Laboratory of Luminescence and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, People's Republic of China
| | - Amit Fischer
- Institute of Chemistry, Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Yu Ouyang
- Institute of Chemistry, Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Jianbang Wang
- Institute of Chemistry, Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Yang Sung Sohn
- Institute of Life Science, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Ola Karmi
- Institute of Life Science, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Rachel Nechushtai
- Institute of Life Science, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Itamar Willner
- Institute of Chemistry, Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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15
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Wu H, Wei T, Yu B, Cheng R, Huang F, Lu X, Yan Y, Wang X, Liu C, Zhu B. A single mutation attenuates both the transcription termination and RNA-dependent RNA polymerase activity of T7 RNA polymerase. RNA Biol 2021; 18:451-466. [PMID: 34314299 PMCID: PMC8677023 DOI: 10.1080/15476286.2021.1954808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 07/05/2021] [Accepted: 07/09/2021] [Indexed: 10/20/2022] Open
Abstract
Transcription termination is one of the least understood processes of gene expression. As the prototype model for transcription studies, the single-subunit T7 RNA polymerase (RNAP) is known to respond to two types of termination signals, but the mechanism underlying such termination, especially the specific elements of the polymerase involved, is still unclear, due to a lack of knowledge with respect to the structure of the termination complex. Here we applied phage-assisted continuous evolution to obtain variants of T7 RNAP that can bypass the typical class I T7 terminator with stem-loop structure. Through in vivo selection and in vitro characterization, we discovered a single mutation (S43Y) that significantly decreased the termination efficiency of T7 RNAP at all transcription terminators tested. Coincidently, the S43Y mutation almost eliminates the RNA-dependent RNAP (RdRp) activity of T7 RNAP without impeding the major DNA-dependent RNAP (DdRp) activity of the enzyme. S43 is located in a hinge region and regulates the transformation between transcription initiation and elongation of T7 RNAP. Steady-state kinetics analysis and an RNA binding assay indicate that the S43Y mutation increases the transcription efficiency while weakening RNA binding of the enzyme. As an enzymatic reagent for in vitro transcription, the T7 RNAP S43Y mutant reduces the undesired termination in run-off RNA synthesis and produces RNA with higher terminal homogeneity.
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Affiliation(s)
- Hui Wu
- Key Laboratory of Molecular Biophysics, the Ministry of Education, College of Life Science and Technology and Shenzhen College, Huazhong University of Science and Technology, Wuhan, HubeiChina
| | - Ting Wei
- CAS Key Laboratory for Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, ShenzhenChina
| | - Bingbing Yu
- Key Laboratory of Molecular Biophysics, the Ministry of Education, College of Life Science and Technology and Shenzhen College, Huazhong University of Science and Technology, Wuhan, HubeiChina
| | - Rui Cheng
- Key Laboratory of Molecular Biophysics, the Ministry of Education, College of Life Science and Technology and Shenzhen College, Huazhong University of Science and Technology, Wuhan, HubeiChina
| | - Fengtao Huang
- Key Laboratory of Molecular Biophysics, the Ministry of Education, College of Life Science and Technology and Shenzhen College, Huazhong University of Science and Technology, Wuhan, HubeiChina
| | - Xuelin Lu
- Key Laboratory of Molecular Biophysics, the Ministry of Education, College of Life Science and Technology and Shenzhen College, Huazhong University of Science and Technology, Wuhan, HubeiChina
| | - Yan Yan
- Key Laboratory of Molecular Biophysics, the Ministry of Education, College of Life Science and Technology and Shenzhen College, Huazhong University of Science and Technology, Wuhan, HubeiChina
| | - Xionglue Wang
- Key Laboratory of Molecular Biophysics, the Ministry of Education, College of Life Science and Technology and Shenzhen College, Huazhong University of Science and Technology, Wuhan, HubeiChina
| | - Chenli Liu
- CAS Key Laboratory for Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, ShenzhenChina
- University of Chinese Academy of Sciences, BeijingChina
| | - Bin Zhu
- Key Laboratory of Molecular Biophysics, the Ministry of Education, College of Life Science and Technology and Shenzhen College, Huazhong University of Science and Technology, Wuhan, HubeiChina
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16
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Gong P. Structural basis of viral RNA-dependent RNA polymerase nucleotide addition cycle in picornaviruses. Enzymes 2021; 49:215-233. [PMID: 34696833 DOI: 10.1016/bs.enz.2021.06.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
RNA-dependent RNA polymerases (RdRPs) encoded by RNA viruses represent a unique class of processive nucleic acid polymerases, carrying out DNA-independent replication/transcription processes. Although viral RdRPs have versatile global structures, they do share a structurally highly conserved active site comprising catalytic motifs A-G. In spite of different initiation modes, the nucleotide addition cycle (NAC) in the RdRP elongation phase probably follows consistent mechanisms. In this chapter, representative structures of picornavirus RdRP elongation complexes are used to illustrate RdRP NAC mechanisms. In the pre-chemistry part of the NAC, RdRPs utilize a unique palm domain-based active site closure that can be further decomposed into two sequential steps. In the post-chemistry part of the NAC, the translocation process is stringently controlled by the RdRP-specific motif G, resulting in asymmetric movements of the template-product RNA. Future efforts to elucidate regulation/intervention mechanisms by mismatched NTPs or nucleotide analog antivirals are necessary to achieve comprehensive understandings of viral RdRP NAC.
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Affiliation(s)
- Peng Gong
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China; Drug Discovery Center for Infectious Diseases, Nankai University, Tianjin, China.
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17
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Long C, Romero ME, La Rocco D, Yu J. Dissecting nucleotide selectivity in viral RNA polymerases. Comput Struct Biotechnol J 2021; 19:3339-3348. [PMID: 34104356 PMCID: PMC8175102 DOI: 10.1016/j.csbj.2021.06.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/28/2021] [Accepted: 06/02/2021] [Indexed: 01/18/2023] Open
Abstract
Designing antiviral therapeutics is of great concern per current pandemics caused by novel coronavirus or SARS-CoV-2. The core polymerase enzyme in the viral replication/transcription machinery is generally conserved and serves well for drug target. In this work we briefly review structural biology and computational clues on representative single-subunit viral polymerases that are more or less connected with SARS-CoV-2 RNA dependent RNA polymerase (RdRp), in particular, to elucidate how nucleotide substrates and potential drug analogs are selected in the viral genome synthesis. To do that, we first survey two well studied RdRps from Polio virus and hepatitis C virus in regard to structural motifs and key residues that have been identified for the nucleotide selectivity. Then we focus on related structural and biochemical characteristics discovered for the SARS-CoV-2 RdRp. To further compare, we summarize what we have learned computationally from phage T7 RNA polymerase (RNAP) on its stepwise nucleotide selectivity, and extend discussion to a structurally similar human mitochondria RNAP, which deserves special attention as it cannot be adversely affected by antiviral treatments. We also include viral phi29 DNA polymerase for comparison, which has both helicase and proofreading activities on top of nucleotide selectivity for replication fidelity control. The helicase and proofreading functions are achieved by protein components in addition to RdRp in the coronavirus replication-transcription machine, with the proofreading strategy important for the fidelity control in synthesizing a comparatively large viral genome.
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Affiliation(s)
- Chunhong Long
- School of Science, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | | | - Daniel La Rocco
- Department of Physics, University of California, Berkeley, CA 94720, USA
| | - Jin Yu
- Department of Physics and Astronomy, Department of Chemistry, NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA 92697, USA
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18
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Cojocaru R, Unrau PJ. Processive RNA polymerization and promoter recognition in an RNA World. Science 2021; 371:1225-1232. [PMID: 33737482 DOI: 10.1126/science.abd9191] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 02/04/2021] [Indexed: 12/21/2022]
Abstract
Early life is thought to have required the self-replication of RNA by RNA replicases. However, how such replicases evolved and subsequently enabled gene expression remains largely unexplored. We engineered and selected a holopolymerase ribozyme that uses a sigma factor-like specificity primer to first recognize an RNA promoter sequence and then, in a second step, rearrange to a processive elongation form. Using its own sequence, the polymerase can also program itself to polymerize from certain RNA promoters and not others. This selective promoter-based polymerization could allow an RNA replicase ribozyme to define "self" from "nonself," an important development for the avoidance of replicative parasites. Moreover, the clamp-like mechanism of this polymerase could eventually enable strand invasion, a critical requirement for replication in the early evolution of life.
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Affiliation(s)
- Razvan Cojocaru
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
| | - Peter J Unrau
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6.
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19
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Wang LJ, Liang L, Liu BJ, Jiang B, Zhang CY. A controlled T7 transcription-driven symmetric amplification cascade machinery for single-molecule detection of multiple repair glycosylases. Chem Sci 2021; 12:5544-5554. [PMID: 34168791 PMCID: PMC8179622 DOI: 10.1039/d1sc00189b] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 02/24/2021] [Indexed: 12/26/2022] Open
Abstract
Genomic oxidation and alkylation are two of the most important forms of cytotoxic damage that may induce mutagenesis, carcinogenicity, and teratogenicity. Human 8-oxoguanine (hOGG1) and alkyladenine DNA glycosylases (hAAG) are responsible for two major forms of oxidative and alkylative damage repair, and their aberrant activities may cause repair deficiencies that are associated with a variety of human diseases, including cancers. Due to their complicated catalytic pathways and hydrolysis mechanisms, simultaneous and accurate detection of multiple repair glycosylases has remained a great challenge. Herein, by taking advantage of unique features of T7-based transcription and the intrinsic superiorities of single-molecule imaging techniques, we demonstrate for the first time the development of a controlled T7 transcription-driven symmetric amplification cascade machinery for single-molecule detection of hOGG1 and hAAG. The presence of hOGG1 and hAAG can remove damaged 8-oxoG and deoxyinosine, respectively, from the dumbbell substrate, resulting in breaking of the dumbbell substrate, unfolding of two loops, and exposure of two T7 promoters simultaneously. The T7 promoters can activate symmetric transcription amplifications with the unfolded loops as the templates, inducing efficient transcription to produce two different single-stranded RNA transcripts (i.e., reporter probes 1 and 2). Reporter probes 1 and 2 hybridize with signal probes 1 and 2, respectively, to initiate duplex-specific nuclease-directed cyclic digestion of the signal probes, liberating large amounts of Cy3 and Cy5 fluorescent molecules. The released Cy3 and Cy5 molecules can be simply measured by total internal reflection fluorescence-based single-molecule detection, with the Cy3 signal indicating the presence of hOGG1 and the Cy5 signal indicating the presence of hAAG. This method exhibits good specificity and high sensitivity with a detection limit of 3.52 × 10-8 U μL-1 for hOGG1 and 3.55 × 10-7 U μL-1 for hAAG, and it can even quantify repair glycosylases at the single-cell level. Moreover, it can be applied for the measurement of kinetic parameters, the screening of potential inhibitors, and the detection of repair glycosylases in human serum, providing a new paradigm for repair enzyme-related biomedical research, drug discovery, and clinical diagnosis.
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Affiliation(s)
- Li-Juan Wang
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University Jinan 250014 China
- School of Chemistry and Chemical Engineering, Southeast University Nanjing 211189 China
| | - Le Liang
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University Jinan 250014 China
| | - Bing-Jie Liu
- Academy of Medical Sciences, Zhengzhou University Zhengzhou 450000 China
| | - BingHua Jiang
- Academy of Medical Sciences, Zhengzhou University Zhengzhou 450000 China
| | - Chun-Yang Zhang
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University Jinan 250014 China
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20
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Basu U, Bostwick AM, Das K, Dittenhafer-Reed KE, Patel SS. Structure, mechanism, and regulation of mitochondrial DNA transcription initiation. J Biol Chem 2020; 295:18406-18425. [PMID: 33127643 PMCID: PMC7939475 DOI: 10.1074/jbc.rev120.011202] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 10/29/2020] [Indexed: 12/14/2022] Open
Abstract
Mitochondria are specialized compartments that produce requisite ATP to fuel cellular functions and serve as centers of metabolite processing, cellular signaling, and apoptosis. To accomplish these roles, mitochondria rely on the genetic information in their small genome (mitochondrial DNA) and the nucleus. A growing appreciation for mitochondria's role in a myriad of human diseases, including inherited genetic disorders, degenerative diseases, inflammation, and cancer, has fueled the study of biochemical mechanisms that control mitochondrial function. The mitochondrial transcriptional machinery is different from nuclear machinery. The in vitro re-constituted transcriptional complexes of Saccharomyces cerevisiae (yeast) and humans, aided with high-resolution structures and biochemical characterizations, have provided a deeper understanding of the mechanism and regulation of mitochondrial DNA transcription. In this review, we will discuss recent advances in the structure and mechanism of mitochondrial transcription initiation. We will follow up with recent discoveries and formative findings regarding the regulatory events that control mitochondrial DNA transcription, focusing on those involved in cross-talk between the mitochondria and nucleus.
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Affiliation(s)
- Urmimala Basu
- Department of Biochemistry and Molecular Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey, USA; Graduate School of Biomedical Sciences, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | | | - Kalyan Das
- Department of Microbiology, Immunology, and Transplantation, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | | | - Smita S Patel
- Department of Biochemistry and Molecular Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey, USA.
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21
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Passalacqua LFM, Dingilian AI, Lupták A. Single-pass transcription by T7 RNA polymerase. RNA (NEW YORK, N.Y.) 2020; 26:2062-2071. [PMID: 32958559 PMCID: PMC7668259 DOI: 10.1261/rna.076778.120] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 09/04/2020] [Indexed: 06/11/2023]
Abstract
RNA molecules can be conveniently synthesized in vitro by the T7 RNA polymerase (T7 RNAP). In some experiments, such as cotranscriptional biochemical analyses, continuous synthesis of RNA is not desired. Here, we propose a method for a single-pass transcription that yields a single transcript per template DNA molecule using the T7 RNAP system. We hypothesized that stalling the polymerase downstream from the promoter region and subsequent cleavage of the promoter by a restriction enzyme (to prevent promoter binding by another polymerase) would allow synchronized production of a single transcript per template. The single-pass transcription was verified in two different scenarios: a short self-cleaving ribozyme and a long mRNA. The results show that a controlled single-pass transcription using T7 RNAP allows precise measurement of cotranscriptional ribozyme activity, and this approach will facilitate the study of other kinetic events.
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Affiliation(s)
- Luiz F M Passalacqua
- Department of Pharmaceutical Sciences, University of California, Irvine, California 92697, USA
| | - Armine I Dingilian
- Department of Pharmaceutical Sciences, University of California, Irvine, California 92697, USA
| | - Andrej Lupták
- Department of Pharmaceutical Sciences, University of California, Irvine, California 92697, USA
- Department of Chemistry, University of California, Irvine, California 92697, USA
- Department of Molecular Biology and Biochemistry, University of California, Irvine, California 92697, USA
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22
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Binas O, de Jesus V, Landgraf T, Völklein AE, Martins J, Hymon D, Kaur Bains J, Berg H, Biedenbänder T, Fürtig B, Lakshmi Gande S, Niesteruk A, Oxenfarth A, Shahin Qureshi N, Schamber T, Schnieders R, Tröster A, Wacker A, Wirmer-Bartoschek J, Wirtz Martin MA, Stirnal E, Azzaoui K, Richter C, Sreeramulu S, José Blommers MJ, Schwalbe H. 19 F NMR-Based Fragment Screening for 14 Different Biologically Active RNAs and 10 DNA and Protein Counter-Screens. Chembiochem 2020; 22:423-433. [PMID: 32794266 PMCID: PMC7436455 DOI: 10.1002/cbic.202000476] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/11/2020] [Indexed: 11/17/2022]
Abstract
We report here the nuclear magnetic resonance 19F screening of 14 RNA targets with different secondary and tertiary structure to systematically assess the druggability of RNAs. Our RNA targets include representative bacterial riboswitches that naturally bind with nanomolar affinity and high specificity to cellular metabolites of low molecular weight. Based on counter‐screens against five DNAs and five proteins, we can show that RNA can be specifically targeted. To demonstrate the quality of the initial fragment library that has been designed for easy follow‐up chemistry, we further show how to increase binding affinity from an initial fragment hit by chemistry that links the identified fragment to the intercalator acridine. Thus, we achieve low‐micromolar binding affinity without losing binding specificity between two different terminator structures.
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Affiliation(s)
- Oliver Binas
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Vanessa de Jesus
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Tom Landgraf
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Albrecht Eduard Völklein
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Jason Martins
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Daniel Hymon
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Jasleen Kaur Bains
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Hannes Berg
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Thomas Biedenbänder
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Boris Fürtig
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Santosh Lakshmi Gande
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Anna Niesteruk
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Andreas Oxenfarth
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Nusrat Shahin Qureshi
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Tatjana Schamber
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Robbin Schnieders
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Alix Tröster
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Anna Wacker
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Julia Wirmer-Bartoschek
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Maria Alexandra Wirtz Martin
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Elke Stirnal
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Kamal Azzaoui
- Saverna Therapeutics, Gewerbestrasse 24, 4123, Allschwil, Switzerland
| | - Christian Richter
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | - Sridhar Sreeramulu
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
| | | | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue Strasse 7, 60438, Frankfurt am Main, Germany
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23
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Sohn BK, Basu U, Lee SW, Cho H, Shen J, Deshpande A, Johnson LC, Das K, Patel SS, Kim H. The dynamic landscape of transcription initiation in yeast mitochondria. Nat Commun 2020; 11:4281. [PMID: 32855416 PMCID: PMC7452894 DOI: 10.1038/s41467-020-17793-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 07/14/2020] [Indexed: 01/24/2023] Open
Abstract
Controlling efficiency and fidelity in the early stage of mitochondrial DNA transcription is crucial for regulating cellular energy metabolism. Conformational transitions of the transcription initiation complex must be central for such control, but how the conformational dynamics progress throughout transcription initiation remains unknown. Here, we use single-molecule fluorescence resonance energy transfer techniques to examine the conformational dynamics of the transcriptional system of yeast mitochondria with single-base resolution. We show that the yeast mitochondrial transcriptional complex dynamically transitions among closed, open, and scrunched states throughout the initiation stage. Then abruptly at position +8, the dynamic states of initiation make a sharp irreversible transition to an unbent conformation with associated promoter release. Remarkably, stalled initiation complexes remain in dynamic scrunching and unscrunching states without dissociating the RNA transcript, implying the existence of backtracking transitions with possible regulatory roles. The dynamic landscape of transcription initiation suggests a kinetically driven regulation of mitochondrial transcription.
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Affiliation(s)
- Byeong-Kwon Sohn
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Urmimala Basu
- Department of Biochemistry and Molecular Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, NJ, 08854, USA
| | - Seung-Won Lee
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Hayoon Cho
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Jiayu Shen
- Department of Biochemistry and Molecular Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, NJ, 08854, USA
| | - Aishwarya Deshpande
- Department of Biochemistry and Molecular Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, NJ, 08854, USA
| | - Laura C Johnson
- Department of Biochemistry and Molecular Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, NJ, 08854, USA
| | - Kalyan Das
- Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000, Leuven, Belgium
| | - Smita S Patel
- Department of Biochemistry and Molecular Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, NJ, 08854, USA.
| | - Hajin Kim
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea.
- Institute for Basic Science, Ulsan, Republic of Korea.
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24
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Maximizing transcription of nucleic acids with efficient T7 promoters. Commun Biol 2020; 3:439. [PMID: 32796901 PMCID: PMC7429497 DOI: 10.1038/s42003-020-01167-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 07/21/2020] [Indexed: 11/08/2022] Open
Abstract
In vitro transcription using T7 bacteriophage polymerase is widely used in molecular biology. Here, we use 5'RACE-Seq to screen a randomized initially transcribed region of the T7 promoter for cross-talk with transcriptional activity. We reveal that sequences from position +4 to +8 downstream of the transcription start site affect T7 promoter activity over a 5-fold range, and identify promoter variants with significantly enhanced transcriptional output that increase the yield of in vitro transcription reactions across a wide range of template concentrations. We furthermore introduce CEL-Seq+ , which uses an optimized T7 promoter to amplify cDNA for single-cell RNA-Sequencing. CEL-Seq+ facilitates scRNA-Seq library preparation, and substantially increases library complexity and the number of expressed genes detected per cell, highlighting a particular value of optimized T7 promoters in bioanalytical applications.
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25
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Abstract
DNA polymerases play a central role in biology by transferring genetic information from one generation to the next during cell division. Harnessing the power of these enzymes in the laboratory has fueled an increase in biomedical applications that involve the synthesis, amplification, and sequencing of DNA. However, the high substrate specificity exhibited by most naturally occurring DNA polymerases often precludes their use in practical applications that require modified substrates. Moving beyond natural genetic polymers requires sophisticated enzyme-engineering technologies that can be used to direct the evolution of engineered polymerases that function with tailor-made activities. Such efforts are expected to uniquely drive emerging applications in synthetic biology by enabling the synthesis, replication, and evolution of synthetic genetic polymers with new physicochemical properties.
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26
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Wu J, Ye HQ, Zhang QY, Lu G, Zhang B, Gong P. A conformation-based intra-molecular initiation factor identified in the flavivirus RNA-dependent RNA polymerase. PLoS Pathog 2020; 16:e1008484. [PMID: 32357182 PMCID: PMC7219791 DOI: 10.1371/journal.ppat.1008484] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 05/13/2020] [Accepted: 03/18/2020] [Indexed: 12/26/2022] Open
Abstract
The flaviviruses pose serious threats to human health. Being a natural fusion of a methyltransferase (MTase) and an RNA-dependent RNA polymerase (RdRP), NS5 is the most conserved flavivirus protein and an important antiviral target. Previously reported NS5 structures represented by those from the Japanese encephalitis virus (JEV) and Dengue virus serotype 3 (DENV3) exhibit two apparently different global conformations, defining two sets of intra-molecular MTase-RdRP interactions. However, whether these NS5 conformations are conserved in flaviviruses and their specific functions remain elusive. Here we report two forms of DENV serotype 2 (DENV2) NS5 crystal structures representing two conformational states with defined analogies to the JEV-mode and DENV3-mode conformations, respectively, demonstrating the conservation of both conformation modes and providing clues for how different conformational states may be interconnected. Data from in vitro polymerase assays further demonstrate that perturbing the JEV-mode but not the DENV3-mode intra-molecular interactions inhibits catalysis only at initiation, while the cell-based virological analysis suggests that both modes of interactions are important for virus proliferation. Our work highlights the role of MTase as a unique intra-molecular initiation factor specifically only through the JEV-mode conformation, providing an example of conformation-based crosstalk between naturally fused protein functional modules.
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Affiliation(s)
- Jiqin Wu
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, China
- University of Chinese Academy of Sciences, Beijing, China
- Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, Hubei, China
| | - Han-Qing Ye
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, China
| | - Qiu-Yan Zhang
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Guoliang Lu
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Bo Zhang
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, China
| | - Peng Gong
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, China
- Drug Discovery Center for Infectious Diseases, Nankai University, Tianjin, China
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27
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Jain N, Blauch LR, Szymanski MR, Das R, Tang SKY, Yin YW, Fire AZ. Transcription polymerase-catalyzed emergence of novel RNA replicons. Science 2020; 368:eaay0688. [PMID: 32217750 PMCID: PMC7445081 DOI: 10.1126/science.aay0688] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 03/09/2020] [Indexed: 12/22/2022]
Abstract
Transcription polymerases can exhibit an unusual mode of regenerating certain RNA templates from RNA, yielding systems that can replicate and evolve with RNA as the information carrier. Two classes of pathogenic RNAs (hepatitis delta virus in animals and viroids in plants) are copied by host transcription polymerases. Using in vitro RNA replication by the transcription polymerase of T7 bacteriophage as an experimental model, we identify hundreds of new replicating RNAs, define three mechanistic hallmarks of replication (subterminal de novo initiation, RNA shape-shifting, and interrupted rolling-circle synthesis), and describe emergence from DNA seeds as a mechanism for the origin of novel RNA replicons. These results inform models for the origins and replication of naturally occurring RNA genetic elements and suggest a means by which diverse RNA populations could be propagated as hereditary material in cellular contexts.
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Affiliation(s)
- Nimit Jain
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Lucas R Blauch
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Michal R Szymanski
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, USA
- Sealy Center for Structural Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
- Intercollegiate Faculty of Biotechnology of the University of Gdansk and Medical University of Gdansk, 80-307 Gdansk, Poland
| | - Rhiju Das
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sindy K Y Tang
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Y Whitney Yin
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, USA
- Sealy Center for Structural Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Andrew Z Fire
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA.
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
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28
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Multiple protein-DNA interfaces unravelled by evolutionary information, physico-chemical and geometrical properties. PLoS Comput Biol 2020; 16:e1007624. [PMID: 32012150 PMCID: PMC7018136 DOI: 10.1371/journal.pcbi.1007624] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 02/13/2020] [Accepted: 12/20/2019] [Indexed: 02/06/2023] Open
Abstract
Interactions between proteins and nucleic acids are at the heart of many essential biological processes. Despite increasing structural information about how these interactions may take place, our understanding of the usage made of protein surfaces by nucleic acids is still very limited. This is in part due to the inherent complexity associated to protein surface deformability and evolution. In this work, we present a method that contributes to decipher such complexity by predicting protein-DNA interfaces and characterizing their properties. It relies on three biologically and physically meaningful descriptors, namely evolutionary conservation, physico-chemical properties and surface geometry. We carefully assessed its performance on several hundreds of protein structures and compared it to several machine-learning state-of-the-art methods. Our approach achieves a higher sensitivity compared to the other methods, with a similar precision. Importantly, we show that it is able to unravel ‘hidden’ binding sites by applying it to unbound protein structures and to proteins binding to DNA via multiple sites and in different conformations. It is also applicable to the detection of RNA-binding sites, without significant loss of performance. This confirms that DNA and RNA-binding sites share similar properties. Our method is implemented as a fully automated tool, JETDNA2, freely accessible at: http://www.lcqb.upmc.fr/JET2DNA. We also provide a new dataset of 187 protein-DNA complex structures, along with a subset of 82 associated unbound structures. The set represents the largest body of high-resolution crystallographic structures of protein-DNA complexes, use biological protein assemblies as DNA-binding units, and covers all major types of protein-DNA interactions. It is available at: http://www.lcqb.upmc.fr/PDNAbenchmarks. Protein-DNA interactions are essential to living organisms and their impairment is associated to many diseases. For these reasons, they have become increasingly important therapeutic targets. Experimental structure determination has revealed different binding motifs and modes, associated to different functions. Yet, the available structural data gives us only a glimpse of the multiplicity and complexity of protein surface usage by DNA. In this work, we use a three-layer model to describe and predict DNA-binding sites at protein surfaces. Given a protein, we consider the way its residues are conserved through evolution, their physico-chemical properties and geometrical shapes to decrypt its surface. We are able to detect a large portion of interacting residues with good precision, even when they are ‘hidden’ by conformational changes. We highlight cases where one protein binds DNA via distinct regions to perform different functions. We are able to uncover the alternative binding sites and relate their properties with their specific roles. Our work can help guiding mutagenesis experiments and the development of new drugs specifically targeting one site while limiting possible side effects.
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29
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Gao W, Xu J, Lian G, Wang X, Gong X, Zhou D, Chang J. A novel analytical principle using AP site-mediated T7 RNA polymerase transcription regulation for sensing uracil-DNA glycosylase activity. Analyst 2020; 145:4321-4327. [DOI: 10.1039/d0an00509f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
udgactivity could regulateT7 RNApolymerase transcription ability by the heteroduplex substrates with chemical modifications.
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Affiliation(s)
- Weichen Gao
- School of Life Sciences
- Tianjin University and Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology (Tianjin)
- Tianjin 300072
- China
| | - Jin Xu
- Tianjin Hospital
- Tianjin 300211
- China
| | - Guowei Lian
- School of Life Sciences
- Tianjin University and Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology (Tianjin)
- Tianjin 300072
- China
| | - Xiaojun Wang
- Department of Toxicology
- Tianjin Centers for Disease Control and Prevention
- Tianjin 300011
- China
| | - Xiaoqun Gong
- School of Life Sciences
- Tianjin University and Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology (Tianjin)
- Tianjin 300072
- China
| | - Dianming Zhou
- Department of Toxicology
- Tianjin Centers for Disease Control and Prevention
- Tianjin 300011
- China
| | - Jin Chang
- School of Life Sciences
- Tianjin University and Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology (Tianjin)
- Tianjin 300072
- China
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30
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Jaïs PH, Decroly E, Jacquet E, Le Boulch M, Jaïs A, Jean-Jean O, Eaton H, Ponien P, Verdier F, Canard B, Goncalves S, Chiron S, Le Gall M, Mayeux P, Shmulevitz M. C3P3-G1: first generation of a eukaryotic artificial cytoplasmic expression system. Nucleic Acids Res 2019; 47:2681-2698. [PMID: 30726994 PMCID: PMC6412113 DOI: 10.1093/nar/gkz069] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Revised: 12/03/2018] [Accepted: 01/25/2019] [Indexed: 12/25/2022] Open
Abstract
Most eukaryotic expression systems make use of host-cell nuclear transcriptional and post-transcriptional machineries. Here, we present the first generation of the chimeric cytoplasmic capping-prone phage polymerase (C3P3-G1) expression system developed by biological engineering, which generates capped and polyadenylated transcripts in host-cell cytoplasm by means of two components. First, an artificial single-unit chimeric enzyme made by fusing an mRNA capping enzyme and a DNA-dependent RNA polymerase. Second, specific DNA templates designed to operate with the C3P3-G1 enzyme, which encode for the transcripts and their artificial polyadenylation. This system, which can potentially be adapted to any in cellulo or in vivo eukaryotic expression applications, was optimized for transient expression in mammalian cells. C3P3-G1 shows promising results for protein production in Chinese Hamster Ovary (CHO-K1) cells. This work also provides avenues for enhancing the performances for next generation C3P3 systems.
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Affiliation(s)
- Philippe H Jaïs
- Eukarÿs SAS, Génopole Campus 3, 4 rue Pierre Fontaine, 91058 Evry Cedex, France
| | - Etienne Decroly
- Architecture et Fonction des Macromolécules Biologiques (AFMB) UMR 7257 CNRS/AMU, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France
| | - Eric Jacquet
- Institut de Chimie des Substances Naturelles, CNRS UPR2301, Université Paris-Saclay, Avenue de la Terrasse, 91198 Gif-sur-Yvette, France
| | - Marine Le Boulch
- Eukarÿs SAS, Génopole Campus 3, 4 rue Pierre Fontaine, 91058 Evry Cedex, France
| | - Aurélien Jaïs
- Eukarÿs SAS, Génopole Campus 3, 4 rue Pierre Fontaine, 91058 Evry Cedex, France
| | - Olivier Jean-Jean
- Sorbonne Université, CNRS-UMR8256, Biological Adaptation and Ageing, Institut de Biologie Paris Seine (B2A-IBPS), F-75252 Paris, France
| | - Heather Eaton
- Medical Microbiology and Immunology, University of Alberta, 6-142J Katz Group Centre for Pharmacy and Health Research, 114 Street NW, Edmonton, Alberta T6G 2E1, Canada
| | - Prishila Ponien
- Institut de Chimie des Substances Naturelles, CNRS UPR2301, Université Paris-Saclay, Avenue de la Terrasse, 91198 Gif-sur-Yvette, France
| | - Fréderique Verdier
- INSERM Unit 1016, Institut Cochin, Bâtiment Gustave Roussy, 27 rue du faubourg Saint-Jacques, 75014 Paris, France
| | - Bruno Canard
- Architecture et Fonction des Macromolécules Biologiques (AFMB) UMR 7257 CNRS/AMU, 163 Avenue de Luminy, 13288 Marseille Cedex 9, France
| | - Sergio Goncalves
- Eukarÿs SAS, Génopole Campus 3, 4 rue Pierre Fontaine, 91058 Evry Cedex, France
| | - Stéphane Chiron
- Eukarÿs SAS, Génopole Campus 3, 4 rue Pierre Fontaine, 91058 Evry Cedex, France
| | - Maude Le Gall
- Gastrointestinal and Metabolic Dysfunctions in Nutritional Pathologies, INSERM UMRS1149, 16 rue Henri Huchard, 75890 Paris Cedex 18, France
| | - Patrick Mayeux
- INSERM Unit 1016, Institut Cochin, Bâtiment Gustave Roussy, 27 rue du faubourg Saint-Jacques, 75014 Paris, France
| | - Maya Shmulevitz
- Medical Microbiology and Immunology, University of Alberta, 6-142J Katz Group Centre for Pharmacy and Health Research, 114 Street NW, Edmonton, Alberta T6G 2E1, Canada
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31
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McManus JB, Emanuel PA, Murray RM, Lux MW. A method for cost-effective and rapid characterization of engineered T7-based transcription factors by cell-free protein synthesis reveals insights into the regulation of T7 RNA polymerase-driven expression. Arch Biochem Biophys 2019; 674:108045. [PMID: 31326518 DOI: 10.1016/j.abb.2019.07.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 06/26/2019] [Accepted: 07/13/2019] [Indexed: 12/20/2022]
Abstract
The T7 bacteriophage RNA polymerase (T7 RNAP) serves as a model for understanding RNA synthesis, as a tool for protein expression, and as an actuator for synthetic gene circuit design in bacterial cells and cell-free extract. T7 RNAP is an attractive tool for orthogonal protein expression in bacteria owing to its compact single subunit structure and orthogonal promoter specificity. Understanding the mechanisms underlying T7 RNAP regulation is important to the design of engineered T7-based transcription factors, which can be used in gene circuit design. To explore regulatory mechanisms for T7 RNAP-driven expression, we developed a rapid and cost-effective method to characterize engineered T7-based transcription factors using cell-free protein synthesis and an acoustic liquid handler. Using this method, we investigated the effects of the tetracycline operator's proximity to the T7 promoter on the regulation of T7 RNAP-driven expression. Our results reveal a mechanism for regulation that functions by interfering with the transition of T7 RNAP from initiation to elongation and validates the use of the method described here to engineer future T7-based transcription factors.
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Affiliation(s)
- John B McManus
- Army Research Laboratory - West Campus, California Institute of Technology, 1200 East California Blvd, Pasadena, CA, 91125, USA
| | - Peter A Emanuel
- US Army Combat Capabilities Development Command Chemical Biological Center, 8198 Blackhawk Rd, APG, MD, 21010, USA
| | - Richard M Murray
- California Institute of Technology, Biology and Biological Engineering, 1200 East California Blvd, Pasadena, CA, 91125, USA
| | - Matthew W Lux
- US Army Combat Capabilities Development Command Chemical Biological Center, 8198 Blackhawk Rd, APG, MD, 21010, USA.
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32
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Gholamalipour Y, Karunanayake Mudiyanselage A, Martin CT. 3' end additions by T7 RNA polymerase are RNA self-templated, distributive and diverse in character-RNA-Seq analyses. Nucleic Acids Res 2019; 46:9253-9263. [PMID: 30219859 PMCID: PMC6182178 DOI: 10.1093/nar/gky796] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 08/23/2018] [Indexed: 11/13/2022] Open
Abstract
Synthetic RNA is widely used in basic science, nanotechnology and therapeutics research. The vast majority of this RNA is synthesized in vitro by T7 RNA polymerase or one of its close family members. However, the desired RNA is generally contaminated with products longer and shorter than the DNA-encoded product. To better understand these undesired byproducts and the processes that generate them, we analyze in vitro transcription reactions using RNA-Seq as a tool. The results unambiguously confirm that product RNA rebinds to the polymerase and self-primes (in cis) generation of a hairpin duplex, a process that favorably competes with promoter driven synthesis under high yield reaction conditions. While certain priming modes can be favored, the process is heterogeneous, both in initial priming and in the extent of priming, and already extended products can rebind for further extension, in a distributive process. Furthermore, addition of one or a few nucleotides, previously termed 'nontemplated addition,' also occurs via templated primer extension. At last, this work demonstrates the utility of RNA-Seq as a tool for in vitro mechanistic studies, providing information far beyond that provided by traditional gel electrophoresis.
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Affiliation(s)
- Yasaman Gholamalipour
- Department of Chemistry, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | | | - Craig T Martin
- Department of Chemistry, University of Massachusetts Amherst, Amherst, MA 01003, USA
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33
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Kouba T, Drncová P, Cusack S. Structural snapshots of actively transcribing influenza polymerase. Nat Struct Mol Biol 2019; 26:460-470. [PMID: 31160782 PMCID: PMC7610713 DOI: 10.1038/s41594-019-0232-z] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 04/18/2019] [Indexed: 12/15/2022]
Abstract
Influenza virus RNA-dependent RNA polymerase uses unique mechanisms to transcribe its single-stranded genomic viral RNA (vRNA) into messenger RNA. The polymerase is initially bound to a promoter comprising the partially base-paired 3' and 5' extremities of the RNA. A short, capped primer, 'cap-snatched' from a nascent host polymerase II transcript, is directed towards the polymerase active site to initiate RNA synthesis. Here we present structural snapshots, as determined by X-ray crystallography and cryo-electron microscopy, of actively initiating influenza polymerase as it transitions towards processive elongation. Unexpected conformational changes unblock the active site cavity to allow establishment of a nine-base-pair template-product RNA duplex before the strands separate into distinct exit channels. Concomitantly, as the template translocates, the promoter base pairs are broken and the template entry region is remodeled. These structures reveal details of the influenza polymerase active site that will help optimize nucleoside analogs or other compounds that directly inhibit viral RNA synthesis.
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Affiliation(s)
- Tomas Kouba
- European Molecular Biology Laboratory, Grenoble, France
| | - Petra Drncová
- European Molecular Biology Laboratory, Grenoble, France
| | - Stephen Cusack
- European Molecular Biology Laboratory, Grenoble, France.
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34
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Long C, E C, Da LT, Yu J. Determining selection free energetics from nucleotide pre-insertion to insertion in viral T7 RNA polymerase transcription fidelity control. Nucleic Acids Res 2019; 47:4721-4735. [PMID: 30916310 PMCID: PMC6511863 DOI: 10.1093/nar/gkz213] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 03/10/2019] [Accepted: 03/18/2019] [Indexed: 01/01/2023] Open
Abstract
An elongation cycle of a transcribing RNA polymerase (RNAP) usually consists of multiple kinetics steps, so there exist multiple kinetic checkpoints where non-cognate nucleotides can be selected against. We conducted comprehensive free energy calculations on various nucleotide insertions for viral T7 RNAP employing all-atom molecular dynamics simulations. By comparing insertion free energy profiles between the non-cognate nucleotide species (rGTP and dATP) and a cognate one (rATP), we obtained selection free energetics from the nucleotide pre-insertion to the insertion checkpoints, and further inferred the selection energetics down to the catalytic stage. We find that the insertion of base mismatch rGTP proceeds mainly through an off-path along which both pre-insertion screening and insertion inhibition play significant roles. In comparison, the selection against dATP is found to go through an off-path pre-insertion screening along with an on-path insertion inhibition. Interestingly, we notice that two magnesium ions switch roles of leave and stay during the dATP on-path insertion. Finally, we infer that substantial selection energetic is still required to catalytically inhibit the mismatched rGTP to achieve an elongation error rate ∼10-4 or lower; while no catalytic selection seems to be further needed against dATP to obtain an error rate ∼10-2.
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Affiliation(s)
- Chunhong Long
- Beijing Computational Science Research Center, Beijing 100193, China
| | - Chao E
- Beijing Computational Science Research Center, Beijing 100193, China
| | - Lin-Tai Da
- Shanghai Center for Systems Biomedicine, Shanghai JiaoTong University, Shanghai 200240, China
| | - Jin Yu
- Beijing Computational Science Research Center, Beijing 100193, China
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35
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Long C, E. C, Da LT, Yu J. A Viral T7 RNA Polymerase Ratcheting Along DNA With Fidelity Control. Comput Struct Biotechnol J 2019; 17:638-644. [PMID: 31193497 PMCID: PMC6535458 DOI: 10.1016/j.csbj.2019.05.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 04/25/2019] [Accepted: 05/04/2019] [Indexed: 12/02/2022] Open
Abstract
RNA polymerase (RNAP) from bacteriophage T7 is a representative single-subunit viral RNAP that can transcribe with high promoter activities without assistances from transcription factors. We accordingly studied this small transcription machine computationally as a model system to understand underlying mechanisms of mechano-chemical coupling and fidelity control in the RNAP transcription elongation. Here we summarize our computational work from several recent publications to demonstrate first how T7 RNAP translocates via Brownian alike motions along DNA right after the catalytic product release. Then we show how the backward translocation motions are prevented at post-translocation upon successful nucleotide incorporation, which is also subject to stepwise nucleotide selection and acts as a pawl for "selective ratcheting". The structural dynamics and energetics features revealed from our atomistic molecular dynamics (MD) simulations and related analyses on the single-subunit T7 RNAP thus provided detailed and quantitative characterizations on the Brownian-ratchet working scenario of a prototypical transcription machine with sophisticated nucleotide selectivity for fidelity control. The presented mechanisms can be more or less general for structurally similar viral or mitochondrial RNAPs and some of DNA polymerases, or even for the RNAP engine of the more complicated transcription machinery in higher organisms.
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Affiliation(s)
- Chunhong Long
- Beijing Computational Science Research Center, Beijing, 100193, China
| | - Chao E.
- Beijing Computational Science Research Center, Beijing, 100193, China
| | - Lin-Tai Da
- Shanghai Center for Systems Biomedicine, Shanghai JiaoTong University, Shanghai 200240, China
| | - Jin Yu
- Beijing Computational Science Research Center, Beijing, 100193, China
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36
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Flamme M, McKenzie LK, Sarac I, Hollenstein M. Chemical methods for the modification of RNA. Methods 2019; 161:64-82. [PMID: 30905751 DOI: 10.1016/j.ymeth.2019.03.018] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 03/18/2019] [Accepted: 03/19/2019] [Indexed: 02/06/2023] Open
Abstract
RNA is often considered as being the vector for the transmission of genetic information from DNA to the protein synthesis machinery. However, besides translation RNA participates in a broad variety of fundamental biological roles such as gene expression and regulation, protein synthesis, and even catalysis of chemical reactions. This variety of function combined with intricate three-dimensional structures and the discovery of over 100 chemical modifications in natural RNAs require chemical methods for the modification of RNAs in order to investigate their mechanism, location, and exact biological roles. In addition, numerous RNA-based tools such as ribozymes, aptamers, or therapeutic oligonucleotides require the presence of additional chemical functionalities to strengthen the nucleosidic backbone against degradation or enhance the desired catalytic or binding properties. Herein, the two main methods for the chemical modification of RNA are presented: solid-phase synthesis using phosphoramidite precursors and the enzymatic polymerization of nucleoside triphosphates. The different synthetic and biochemical steps required for each method are carefully described and recent examples of practical applications based on these two methods are discussed.
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Affiliation(s)
- Marie Flamme
- Institut Pasteur, Department of Structural Biology and Chemistry, Laboratory for Bioorganic Chemistry of Nucleic Acids, CNRS UMR3523, 28, rue du Docteur Roux, 75724 Paris Cedex 15, France; Sorbonne Université, Collège doctoral, F-75005 Paris, France
| | - Luke K McKenzie
- Institut Pasteur, Department of Structural Biology and Chemistry, Laboratory for Bioorganic Chemistry of Nucleic Acids, CNRS UMR3523, 28, rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Ivo Sarac
- Institut Pasteur, Department of Structural Biology and Chemistry, Laboratory for Bioorganic Chemistry of Nucleic Acids, CNRS UMR3523, 28, rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Marcel Hollenstein
- Institut Pasteur, Department of Structural Biology and Chemistry, Laboratory for Bioorganic Chemistry of Nucleic Acids, CNRS UMR3523, 28, rue du Docteur Roux, 75724 Paris Cedex 15, France.
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37
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Milisavljevič N, Perlíková P, Pohl R, Hocek M. Enzymatic synthesis of base-modified RNA by T7 RNA polymerase. A systematic study and comparison of 5-substituted pyrimidine and 7-substituted 7-deazapurine nucleoside triphosphates as substrates. Org Biomol Chem 2019; 16:5800-5807. [PMID: 30063056 DOI: 10.1039/c8ob01498a] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
We synthesized a small library of eighteen 5-substituted pyrimidine or 7-substituted 7-deazapurine nucleoside triphosphates bearing methyl, ethynyl, phenyl, benzofuryl or dibenzofuryl groups through cross-coupling reactions of nucleosides followed by triphosphorylation or through direct cross-coupling reactions of halogenated nucleoside triphosphates. We systematically studied the influence of the modification on the efficiency of T7 RNA polymerase catalyzed synthesis of modified RNA and found that modified ATP, UTP and CTP analogues bearing smaller modifications were good substrates and building blocks for the RNA synthesis even in difficult sequences incorporating multiple modified nucleotides. Bulky dibenzofuryl derivatives of ATP and GTP were not substrates for the RNA polymerase. In the case of modified GTP analogues, a modified procedure using a special promoter and GMP as initiator needed to be used to obtain efficient RNA synthesis. The T7 RNA polymerase synthesis of modified RNA can be very efficiently used for synthesis of modified RNA but the method has constraints in the sequence of the first three nucleotides of the transcript, which must contain a non-modified G in the +1 position.
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Affiliation(s)
- Nemanja Milisavljevič
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nam. 2, CZ-16610, Prague 6, Czech Republic.
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38
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Gao Y, Cui Y, Fox T, Lin S, Wang H, de Val N, Zhou ZH, Yang W. Structures and operating principles of the replisome. Science 2019; 363:science.aav7003. [PMID: 30679383 DOI: 10.1126/science.aav7003] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 01/13/2019] [Indexed: 12/12/2022]
Abstract
Visualization in atomic detail of the replisome that performs concerted leading- and lagging-DNA strand synthesis at a replication fork has not been reported. Using bacteriophage T7 as a model system, we determined cryo-electron microscopy structures up to 3.2-angstroms resolution of helicase translocating along DNA and of helicase-polymerase-primase complexes engaging in synthesis of both DNA strands. Each domain of the spiral-shaped hexameric helicase translocates sequentially hand-over-hand along a single-stranded DNA coil, akin to the way AAA+ ATPases (adenosine triphosphatases) unfold peptides. Two lagging-strand polymerases are attached to the primase, ready for Okazaki fragment synthesis in tandem. A β hairpin from the leading-strand polymerase separates two parental DNA strands into a T-shaped fork, thus enabling the closely coupled helicase to advance perpendicular to the downstream DNA duplex. These structures reveal the molecular organization and operating principles of a replisome.
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Affiliation(s)
- Yang Gao
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yanxiang Cui
- The California NanoSystems Institute, UCLA, Los Angeles, CA 90095, USA
| | - Tara Fox
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.,Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., Frederick, MD 21701, USA
| | - Shiqiang Lin
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Huaibin Wang
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Natalia de Val
- Center for Molecular Microscopy, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.,Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research Inc., Frederick, MD 21701, USA
| | - Z Hong Zhou
- The California NanoSystems Institute, UCLA, Los Angeles, CA 90095, USA
| | - Wei Yang
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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39
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Kim SH, Ganji M, Kim E, van der Torre J, Abbondanzieri E, Dekker C. DNA sequence encodes the position of DNA supercoils. eLife 2018; 7:e36557. [PMID: 30523779 PMCID: PMC6301789 DOI: 10.7554/elife.36557] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Accepted: 12/06/2018] [Indexed: 12/13/2022] Open
Abstract
The three-dimensional organization of DNA is increasingly understood to play a decisive role in vital cellular processes. Many studies focus on the role of DNA-packaging proteins, crowding, and confinement in arranging chromatin, but structural information might also be directly encoded in bare DNA itself. Here, we visualize plectonemes (extended intertwined DNA structures formed upon supercoiling) on individual DNA molecules. Remarkably, our experiments show that the DNA sequence directly encodes the structure of supercoiled DNA by pinning plectonemes at specific sequences. We develop a physical model that predicts that sequence-dependent intrinsic curvature is the key determinant of pinning strength and demonstrate this simple model provides very good agreement with the data. Analysis of several prokaryotic genomes indicates that plectonemes localize directly upstream of promoters, which we experimentally confirm for selected promotor sequences. Our findings reveal a hidden code in the genome that helps to spatially organize the chromosomal DNA.
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Affiliation(s)
- Sung Hyun Kim
- Department of BionanoscienceKavli Institute of Nanoscience, Delft University of TechnologyDelftThe Netherlands
| | - Mahipal Ganji
- Department of BionanoscienceKavli Institute of Nanoscience, Delft University of TechnologyDelftThe Netherlands
| | - Eugene Kim
- Department of BionanoscienceKavli Institute of Nanoscience, Delft University of TechnologyDelftThe Netherlands
| | - Jaco van der Torre
- Department of BionanoscienceKavli Institute of Nanoscience, Delft University of TechnologyDelftThe Netherlands
| | - Elio Abbondanzieri
- Department of BionanoscienceKavli Institute of Nanoscience, Delft University of TechnologyDelftThe Netherlands
| | - Cees Dekker
- Department of BionanoscienceKavli Institute of Nanoscience, Delft University of TechnologyDelftThe Netherlands
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40
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Chim N, Jackson LN, Trinh AM, Chaput JC. Crystal structures of DNA polymerase I capture novel intermediates in the DNA synthesis pathway. eLife 2018; 7:40444. [PMID: 30338759 PMCID: PMC6231770 DOI: 10.7554/elife.40444] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 10/18/2018] [Indexed: 11/13/2022] Open
Abstract
High resolution crystal structures of DNA polymerase intermediates are needed to study the mechanism of DNA synthesis in cells. Here we report five crystal structures of DNA polymerase I that capture new conformations for the polymerase translocation and nucleotide pre-insertion steps in the DNA synthesis pathway. We suggest that these new structures, along with previously solved structures, highlight the dynamic nature of the finger subdomain in the enzyme active site. DNA molecules consist of two separate strands that spiral around each other to form a structure called the double helix. Each strand contains repeating units, with every unit consisting of a phosphate group and a sugar molecule bound to one of four bases. The two strands are held together by bonds between the bases. When a cell divides, it needs to make a copy of the DNA, so that each new cell will have an exact replica from the old cell. During this process, the helix unwinds and enzymes called polymerases produce new strands (using the old ones as a template). Each strand is copied by adding new bases one at a time. Every time a new base is added, the polymerases must modify their structures several times. If this process becomes faulty, it can lead to various diseases, including cancer. Scientist often use a technique called X-ray crystallography to study intermediate structures of frozen polymerase crystals as the enzyme constructs DNA. Yet, to fully understand the mechanisms of DNA synthesis all intermediate structures need to be identified. Now, Chim, Jackson et al. used a particular method for making frozen polymerase crytals by allowing the enzyme to add new bases in liquid form. The reaction was then frozen and X-ray crystallography was used to take images. This modified method captured different steps in the process and detailed how the enzyme adjusts its structure as it moves along the template strand. The intermediate structures that Chim, Jackson et al. uncovered may help scientists develop new biotechnologies and medicines. Understanding how polymerases modify their form while making DNA copies could lead to better therapies for diseases in which this process has become faulty, like cancer.
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Affiliation(s)
- Nicholas Chim
- Departments of Pharmaceutical Sciences, University of California, Irvine, California
| | - Lynnette N Jackson
- Departments of Pharmaceutical Sciences, University of California, Irvine, California
| | - Anh M Trinh
- Departments of Pharmaceutical Sciences, University of California, Irvine, California
| | - John C Chaput
- Departments of Pharmaceutical Sciences, University of California, Irvine, California.,Department of Chemistry, University of California, Irvine, California.,Department of Molecular Biology and Biochemistry, University of California, Irvine, California
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41
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Borkotoky S, Murali A. The highly efficient T7 RNA polymerase: A wonder macromolecule in biological realm. Int J Biol Macromol 2018; 118:49-56. [DOI: 10.1016/j.ijbiomac.2018.05.198] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 05/25/2018] [Accepted: 05/26/2018] [Indexed: 12/01/2022]
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42
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Structural basis of mitochondrial transcription. Nat Struct Mol Biol 2018; 25:754-765. [PMID: 30190598 DOI: 10.1038/s41594-018-0122-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 07/29/2018] [Indexed: 01/17/2023]
Abstract
The mitochondrial genome is transcribed by a single-subunit DNA-dependent RNA polymerase (mtRNAP) and its auxiliary factors. Structural studies have elucidated how mtRNAP cooperates with its dedicated transcription factors to direct RNA synthesis: initiation factors TFAM and TFB2M assist in promoter-DNA binding and opening by mtRNAP while the elongation factor TEFM increases polymerase processivity to the levels required for synthesis of long polycistronic mtRNA transcripts. Here, we review the emerging body of structural and functional studies of human mitochondrial transcription, provide a molecular movie that can be used for teaching purposes and discuss the open questions to guide future directions of investigation.
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43
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Kulkarni P, Solomon TL, He Y, Chen Y, Bryan PN, Orban J. Structural metamorphism and polymorphism in proteins on the brink of thermodynamic stability. Protein Sci 2018; 27:1557-1567. [PMID: 30144197 PMCID: PMC6194243 DOI: 10.1002/pro.3458] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 06/11/2018] [Indexed: 12/13/2022]
Abstract
The classical view of the structure-function paradigm advanced by Anfinsen in the 1960s is that a protein's function is inextricably linked to its three-dimensional structure and is encrypted in its amino acid sequence. However, it is now known that a significant fraction of the proteome consists of intrinsically disordered proteins (IDPs). These proteins populate a polymorphic ensemble of conformations rather than a unique structure but are still capable of performing biological functions. At the boundary, between well-ordered and inherently disordered states are proteins that are on the brink of stability, either weakly stable ordered systems or disordered but on the verge of being stable. In such marginal states, even relatively minor changes can significantly alter the energy landscape, leading to large-scale conformational remodeling. Some proteins on the edge of stability are metamorphic, with the capacity to switch from one fold topology to another in response to an environmental trigger (e.g., pH, temperature/salt, redox). Many IDPs, on the other hand, are marginally unstable such that small perturbations (e.g., phosphorylation, ligands) tip the balance over to a range of ordered, partially ordered, or even more disordered states. In general, the structural transitions described by metamorphic fold switches and polymorphic IDPs possess a number of common features including low or diminished stability, large-scale conformational changes, critical disordered regions, latent or attenuated binding sites, and expansion of function. We suggest that these transitions are, therefore, conceptually and mechanistically analogous, representing adjacent regions in the continuum of order/disorder transitions.
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Affiliation(s)
- Prakash Kulkarni
- W. M. Keck Laboratory for Structural BiologyUniversity of Maryland Institute for Bioscience and Biotechnology ResearchRockvilleMaryland20850
| | - Tsega L. Solomon
- W. M. Keck Laboratory for Structural BiologyUniversity of Maryland Institute for Bioscience and Biotechnology ResearchRockvilleMaryland20850
| | - Yanan He
- W. M. Keck Laboratory for Structural BiologyUniversity of Maryland Institute for Bioscience and Biotechnology ResearchRockvilleMaryland20850
| | - Yihong Chen
- W. M. Keck Laboratory for Structural BiologyUniversity of Maryland Institute for Bioscience and Biotechnology ResearchRockvilleMaryland20850
| | - Philip N. Bryan
- W. M. Keck Laboratory for Structural BiologyUniversity of Maryland Institute for Bioscience and Biotechnology ResearchRockvilleMaryland20850
| | - John Orban
- W. M. Keck Laboratory for Structural BiologyUniversity of Maryland Institute for Bioscience and Biotechnology ResearchRockvilleMaryland20850
- Department of Chemistry and BiochemistryUniversity of MarylandCollege ParkMaryland20742
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44
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Molodtsov V, Murakami KS. Minimalism and functionality: Structural lessons from the heterodimeric N4 bacteriophage RNA polymerase II. J Biol Chem 2018; 293:13616-13625. [PMID: 29991593 PMCID: PMC6120196 DOI: 10.1074/jbc.ra118.003447] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 06/19/2018] [Indexed: 01/07/2023] Open
Abstract
Genomes of phages, mitochondria, and chloroplasts are transcribed by a diverse group of transcriptional machineries with structurally related single-subunit RNA polymerases (RNAPs). Our understanding of transcription mechanisms of these enzymes is predominantly based on biochemical and structural studies of three most-studied members, transcription factor-independent phage T7 RNAP, transcription factor-dependent phage N4 virion-encapsidated RNAP, and transcription factor-dependent mitochondrial RNAPs (mtRNAP). Although these RNAPs employ completely different mechanisms for promoter recognition and transcription termination, these enzymes are relatively large and formed by single polypeptides. Historically being a model enzyme for studying the mechanisms of transcription by T7-like RNAPs, however, T7 RNAP represents only a small group of RNAPs in this family. The vast majority of T7-like RNAPs are transcription factor-dependent, and several of them are heterodimeric enzymes. Here, we report X-ray crystal structures of transcription complexes of the smallest and heterodimeric form of T7-like RNAP, bacteriophage N4 RNAPII, providing insights into the structural organization of a minimum RNAP in this family. We analyze structural and functional aspects of heterodimeric architecture of N4 RNAPII concerning the mechanisms of transcription initiation and transition to processive RNA elongation. Interestingly, N4 RNAPII maintains the same conformation in promoter-bound and elongation transcription complexes, revealing a novel transcription mechanism for single-subunit RNAPs. This work establishes a structural basis for studying mechanistic aspects of transcription by factor-dependent minimum RNAP.
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Affiliation(s)
- Vadim Molodtsov
- From the Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, To whom correspondence may be addressed. E-mail:
| | - Katsuhiko S. Murakami
- From the Department of Biochemistry and Molecular Biology, The Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, To whom correspondence may be addressed. E-mail:
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45
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Koh HR, Roy R, Sorokina M, Tang GQ, Nandakumar D, Patel SS, Ha T. Correlating Transcription Initiation and Conformational Changes by a Single-Subunit RNA Polymerase with Near Base-Pair Resolution. Mol Cell 2018; 70:695-706.e5. [PMID: 29775583 PMCID: PMC5983381 DOI: 10.1016/j.molcel.2018.04.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 02/23/2018] [Accepted: 04/19/2018] [Indexed: 11/20/2022]
Abstract
We provide a comprehensive analysis of transcription in real time by T7 RNA Polymerase (RNAP) using single-molecule fluorescence resonance energy transfer by monitoring the entire life history of transcription initiation, including stepwise RNA synthesis with near base-pair resolution, abortive cycling, and transition into elongation. Kinetically branching pathways were observed for abortive initiation with an RNAP either recycling on the same promoter or exchanging with another RNAP from solution. We detected fast and slow populations of RNAP in their transition into elongation, consistent with the efficient and delayed promoter release, respectively, observed in ensemble studies. Real-time monitoring of abortive cycling using three-probe analysis showed that the initiation events are stochastically branched into productive and failed transcription. The abortive products are generated primarily from initiation events that fail to progress to elongation, and a majority of the productive events transit to elongation without making abortive products.
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Affiliation(s)
- Hye Ran Koh
- Department of Physics and Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Chemistry, Chung-Ang University, Seoul 06974, Korea
| | - Rahul Roy
- Department of Physics and Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Maria Sorokina
- Department of Physics and Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Guo-Qing Tang
- Department of Biochemistry and Molecular Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | - Divya Nandakumar
- Department of Biochemistry and Molecular Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | - Smita S Patel
- Department of Biochemistry and Molecular Biology, Rutgers University, Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
| | - Taekjip Ha
- Department of Physics and Center for the Physics of Living Cells, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Howard Hughes Medical Institute, Baltimore, MD 21205, USA; Departments of Biophysics and Biophysical Chemistry, Biophysics, and Biomedical Engineering, Johns Hopkins University, MD 21205, USA.
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46
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Abstract
The ability of bacterial cells to adjust their gene expression program in response to environmental perturbation is often critical for their survival. Recent experimental advances allowing us to quantitatively record gene expression dynamics in single cells and in populations coupled with mathematical modeling enable mechanistic understanding on how these responses are shaped by the underlying regulatory networks. Here, we review how the combination of local and global factors affect dynamical responses of gene regulatory networks. Our goal is to discuss the general principles that allow extrapolation from a few model bacteria to less understood microbes. We emphasize that, in addition to well-studied effects of network architecture, network dynamics are shaped by global pleiotropic effects and cell physiology.
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Affiliation(s)
- David L Shis
- Department of Biosciences, Rice University, Houston, Texas 77005, USA;
| | - Matthew R Bennett
- Department of Biosciences, Rice University, Houston, Texas 77005, USA; .,Department of Bioengineering, Rice University, Houston, Texas 77005, USA
| | - Oleg A Igoshin
- Department of Biosciences, Rice University, Houston, Texas 77005, USA; .,Department of Bioengineering, Rice University, Houston, Texas 77005, USA.,Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005, USA
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47
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Hillen HS, Morozov YI, Sarfallah A, Temiakov D, Cramer P. Structural Basis of Mitochondrial Transcription Initiation. Cell 2017; 171:1072-1081.e10. [PMID: 29149603 DOI: 10.1016/j.cell.2017.10.036] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 10/18/2017] [Accepted: 10/22/2017] [Indexed: 12/31/2022]
Abstract
Transcription in human mitochondria is driven by a single-subunit, factor-dependent RNA polymerase (mtRNAP). Despite its critical role in both expression and replication of the mitochondrial genome, transcription initiation by mtRNAP remains poorly understood. Here, we report crystal structures of human mitochondrial transcription initiation complexes assembled on both light and heavy strand promoters. The structures reveal how transcription factors TFAM and TFB2M assist mtRNAP to achieve promoter-dependent initiation. TFAM tethers the N-terminal region of mtRNAP to recruit the polymerase to the promoter whereas TFB2M induces structural changes in mtRNAP to enable promoter opening and trapping of the DNA non-template strand. Structural comparisons demonstrate that the initiation mechanism in mitochondria is distinct from that in the well-studied nuclear, bacterial, or bacteriophage transcription systems but that similarities are found on the topological and conceptual level. These results provide a framework for studying the regulation of gene expression and DNA replication in mitochondria.
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Affiliation(s)
- Hauke S Hillen
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Yaroslav I Morozov
- Department of Cell Biology, Rowan University, School of Osteopathic Medicine, 2 Medical Center Dr., Stratford, NJ 08084, USA
| | - Azadeh Sarfallah
- Department of Cell Biology, Rowan University, School of Osteopathic Medicine, 2 Medical Center Dr., Stratford, NJ 08084, USA
| | - Dmitry Temiakov
- Department of Cell Biology, Rowan University, School of Osteopathic Medicine, 2 Medical Center Dr., Stratford, NJ 08084, USA.
| | - Patrick Cramer
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
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48
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Continuous directed evolution of aminoacyl-tRNA synthetases. Nat Chem Biol 2017; 13:1253-1260. [PMID: 29035361 PMCID: PMC5724969 DOI: 10.1038/nchembio.2474] [Citation(s) in RCA: 154] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 08/08/2017] [Indexed: 12/19/2022]
Abstract
Directed evolution of orthogonal aminoacyl-tRNA synthetases (AARSs) enables site-specific installation of non-canonical amino acids (ncAAs) into proteins. Traditional evolution techniques typically produce AARSs with greatly reduced activity and selectivity compared to their wild-type counterparts. We designed phage-assisted continuous evolution (PACE) selections to rapidly produce highly active and selective orthogonal AARSs through hundreds of generations of evolution. PACE of a chimeric Methanosarcina spp. pyrrolysyl-tRNA synthetase (PylRS) improved its enzymatic efficiency (kcat/KMtRNA) 45-fold compared to the parent enzyme. Transplantation of the evolved mutations into other PylRS-derived synthetases improved yields of proteins containing non-canonical residues up to 9.7-fold. Simultaneous positive and negative selection PACE over 48 h greatly improved the selectivity of a promiscuous Methanocaldococcus jannaschii tyrosyl-tRNA synthetase variant for site-specific incorporation of p-iodo-L-phenylalanine. These findings offer new AARSs that increase the utility of orthogonal translation systems and establish the capability of PACE to efficiently evolve orthogonal AARSs with high activity and amino acid specificity.
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49
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Hillen HS, Parshin AV, Agaronyan K, Morozov YI, Graber JJ, Chernev A, Schwinghammer K, Urlaub H, Anikin M, Cramer P, Temiakov D. Mechanism of Transcription Anti-termination in Human Mitochondria. Cell 2017; 171:1082-1093.e13. [PMID: 29033127 DOI: 10.1016/j.cell.2017.09.035] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 07/27/2017] [Accepted: 09/18/2017] [Indexed: 11/18/2022]
Abstract
In human mitochondria, transcription termination events at a G-quadruplex region near the replication origin are thought to drive replication of mtDNA by generation of an RNA primer. This process is suppressed by a key regulator of mtDNA-the transcription factor TEFM. We determined the structure of an anti-termination complex in which TEFM is bound to transcribing mtRNAP. The structure reveals interactions of the dimeric pseudonuclease core of TEFM with mobile structural elements in mtRNAP and the nucleic acid components of the elongation complex (EC). Binding of TEFM to the DNA forms a downstream "sliding clamp," providing high processivity to the EC. TEFM also binds near the RNA exit channel to prevent formation of the RNA G-quadruplex structure required for termination and thus synthesis of the replication primer. Our data provide insights into target specificity of TEFM and mechanisms by which it regulates the switch between transcription and replication of mtDNA.
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Affiliation(s)
- Hauke S Hillen
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Andrey V Parshin
- Department of Cell Biology, Rowan University, School of Osteopathic Medicine, 2 Medical Center Drive, Stratford, NJ 08084, USA
| | - Karen Agaronyan
- Department of Cell Biology, Rowan University, School of Osteopathic Medicine, 2 Medical Center Drive, Stratford, NJ 08084, USA
| | - Yaroslav I Morozov
- Department of Cell Biology, Rowan University, School of Osteopathic Medicine, 2 Medical Center Drive, Stratford, NJ 08084, USA
| | - James J Graber
- Department of Cell Biology, Rowan University, School of Osteopathic Medicine, 2 Medical Center Drive, Stratford, NJ 08084, USA
| | - Aleksandar Chernev
- Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany; Bioanalytics, Institute for Clinical Chemistry, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Kathrin Schwinghammer
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany; Bioanalytics, Institute for Clinical Chemistry, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Michael Anikin
- Department of Cell Biology, Rowan University, School of Osteopathic Medicine, 2 Medical Center Drive, Stratford, NJ 08084, USA
| | - Patrick Cramer
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
| | - Dmitry Temiakov
- Department of Cell Biology, Rowan University, School of Osteopathic Medicine, 2 Medical Center Drive, Stratford, NJ 08084, USA.
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50
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Da LT, E C, Shuai Y, Wu S, Su XD, Yu J. T7 RNA polymerase translocation is facilitated by a helix opening on the fingers domain that may also prevent backtracking. Nucleic Acids Res 2017; 45:7909-7921. [PMID: 28575393 PMCID: PMC5737862 DOI: 10.1093/nar/gkx495] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 05/24/2017] [Indexed: 12/04/2022] Open
Abstract
Here, we studied the complete process of a viral T7 RNA polymerase (RNAP) translocation on DNA during transcription elongation by implementing extensive all-atom molecular dynamics (MD) simulations to construct a Markov state model (MSM). Our studies show that translocation proceeds in a Brownian motion, and the RNAP thermally transits among multiple metastable states. We observed non-synchronized backbone movements of the nucleic acid (NA) chains with the RNA translocation accomplished first, while the template DNA lagged. Notably, both the O-helix and Y-helix on the fingers domain play key roles in facilitating NA translocation through the helix opening. The helix opening allows a key residue Tyr639 to become inserted into the active site, which pushes the RNA–DNA hybrid forward. Another key residue, Phe644, coordinates the downstream template DNA motions by stacking and un-stacking with a transition nucleotide (TN) and its adjacent nucleotide. Moreover, the O-helix opening at pre-translocation (pre-trans) likely resists backtracking. To test this hypothesis, we computationally designed mutants of T7 RNAP by replacing the amino acids on the O-helix with counterpart residues from a mitochondrial RNAP that is capable of backtracking. The current experimental results support the hypothesis.
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Affiliation(s)
- Lin-Tai Da
- Beijing Computational Science Research Center, Beijing 100193, China.,Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Center for Systems Biomedicine, Shanghai JiaoTong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Chao E
- Beijing Computational Science Research Center, Beijing 100193, China
| | - Yao Shuai
- School of Life Sciences, Peking University, Beijing 100871, China
| | - Shaogui Wu
- Beijing Computational Science Research Center, Beijing 100193, China
| | - Xiao-Dong Su
- School of Life Sciences, Peking University, Beijing 100871, China
| | - Jin Yu
- Beijing Computational Science Research Center, Beijing 100193, China
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