1
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Uckelmann M, Levina V, Taveneau C, Ng XH, Pandey V, Martinez J, Mendiratta S, Houx J, Boudes M, Venugopal H, Trépout S, Zhang Q, Flanigan S, Li M, Sierecki E, Gambin Y, Das PP, Bell O, de Marco A, Davidovich C. Dynamic PRC1-CBX8 stabilizes a porous structure of chromatin condensates. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.05.08.539931. [PMID: 38405976 PMCID: PMC10888862 DOI: 10.1101/2023.05.08.539931] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
The compaction of chromatin is a prevalent paradigm in gene repression. Chromatin compaction is commonly thought to repress transcription by restricting chromatin accessibility. However, the spatial organisation and dynamics of chromatin compacted by gene-repressing factors are unknown. Using cryo-electron tomography, we solved the three-dimensional structure of chromatin condensed by the Polycomb Repressive Complex 1 (PRC1) in a complex with CBX8. PRC1-condensed chromatin is porous and stabilised through multivalent dynamic interactions of PRC1 with chromatin. Mechanistically, positively charged residues on the internally disordered regions (IDRs) of CBX8 mask negative charges on the DNA to stabilize the condensed state of chromatin. Within condensates, PRC1 remains dynamic while maintaining a static chromatin structure. In differentiated mouse embryonic stem cells, CBX8-bound chromatin remains accessible. These findings challenge the idea of rigidly compacted polycomb domains and instead provides a mechanistic framework for dynamic and accessible PRC1-chromatin condensates.
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2
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Wang Z, Ke J, Guo Z, Wang Y, Lei K, Wang S, Chen G, Shen Z, Li W, Ou G. Transposase-assisted tagmentation: an economical and scalable strategy for single-worm whole-genome sequencing. G3 (BETHESDA, MD.) 2024; 14:jkae094. [PMID: 38856093 PMCID: PMC11228870 DOI: 10.1093/g3journal/jkae094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Accepted: 04/21/2024] [Indexed: 06/11/2024]
Abstract
AlphaMissense identifies 23 million human missense variants as likely pathogenic, but only 0.1% have been clinically classified. To experimentally validate these predictions, chemical mutagenesis presents a rapid, cost-effective method to produce billions of mutations in model organisms. However, the prohibitive costs and limitations in the throughput of whole-genome sequencing (WGS) technologies, crucial for variant identification, constrain its widespread application. Here, we introduce a Tn5 transposase-assisted tagmentation technique for conducting WGS in Caenorhabditis elegans, Escherichia coli, Saccharomyces cerevisiae, and Chlamydomonas reinhardtii. This method, demands merely 20 min of hands-on time for a single-worm or single-cell clones and incurs a cost below 10 US dollars. It effectively pinpoints causal mutations in mutants defective in cilia or neurotransmitter secretion and in mutants synthetically sterile with a variant analogous to the B-Raf Proto-oncogene, Serine/Threonine Kinase (BRAF) V600E mutation. Integrated with chemical mutagenesis, our approach can generate and identify missense variants economically and efficiently, facilitating experimental investigations of missense variants in diverse species.
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Affiliation(s)
- Zi Wang
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences and MOE Key Laboratory for Protein Science, McGovern Institute for Brain Research, Tsinghua University, Beijing 100190, China
| | - Jingyi Ke
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences and MOE Key Laboratory for Protein Science, McGovern Institute for Brain Research, Tsinghua University, Beijing 100190, China
| | - Zhengyang Guo
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences and MOE Key Laboratory for Protein Science, McGovern Institute for Brain Research, Tsinghua University, Beijing 100190, China
| | - Yang Wang
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences and MOE Key Laboratory for Protein Science, McGovern Institute for Brain Research, Tsinghua University, Beijing 100190, China
| | - Kexin Lei
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences and MOE Key Laboratory for Protein Science, McGovern Institute for Brain Research, Tsinghua University, Beijing 100190, China
| | - Shimin Wang
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences and MOE Key Laboratory for Protein Science, McGovern Institute for Brain Research, Tsinghua University, Beijing 100190, China
| | - Guanghan Chen
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences and MOE Key Laboratory for Protein Science, McGovern Institute for Brain Research, Tsinghua University, Beijing 100190, China
| | - Zijie Shen
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences and MOE Key Laboratory for Protein Science, McGovern Institute for Brain Research, Tsinghua University, Beijing 100190, China
| | - Wei Li
- School of Medicine, Tsinghua University, Beijing 100190, China
| | - Guangshuo Ou
- State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, Beijing Frontier Research Center for Biological Structure, School of Life Sciences and MOE Key Laboratory for Protein Science, McGovern Institute for Brain Research, Tsinghua University, Beijing 100190, China
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3
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Giengkam S, Kullapanich C, Wongsantichon J, Adcox HE, Gillespie JJ, Salje J. Orientia tsutsugamushi: comprehensive analysis of the mobilome of a highly fragmented and repetitive genome reveals the capacity for ongoing lateral gene transfer in an obligate intracellular bacterium. mSphere 2023; 8:e0026823. [PMID: 37850800 PMCID: PMC10732058 DOI: 10.1128/msphere.00268-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 08/22/2023] [Indexed: 10/19/2023] Open
Abstract
IMPORTANCE Obligate intracellular bacteria, or those only capable of growth inside other living cells, have limited opportunities for horizontal gene transfer with other microbes due to their isolated replicative niche. The human pathogen Ot, an obligate intracellular bacterium causing scrub typhus, encodes an unusually high copy number of a ~40 gene mobile genetic element that typically facilitates genetic transfer across microbes. This proliferated element is heavily degraded in Ot and previously assumed to be inactive. Here, we conducted a detailed analysis of this element in eight Ot strains and discovered two strains with at least one intact copy. This implies that the element is still capable of moving across Ot populations and suggests that the genome of this bacterium may be even more dynamic than previously appreciated. Our work raises questions about intracellular microbial evolution and sounds an alarm for gene-based efforts focused on diagnosing and combatting scrub typhus.
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Affiliation(s)
- Suparat Giengkam
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Chitrasak Kullapanich
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Jantana Wongsantichon
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Haley E. Adcox
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, Virginia, USA
| | - Joseph J. Gillespie
- Department of Microbiology and Immunology, School of Medicine, University of Maryland Baltimore, Baltimore, Maryland, USA
| | - Jeanne Salje
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
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4
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Han M, Perkins MH, Novaes LS, Xu T, Chang H. Advances in transposable elements: from mechanisms to applications in mammalian genomics. Front Genet 2023; 14:1290146. [PMID: 38098473 PMCID: PMC10719622 DOI: 10.3389/fgene.2023.1290146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 11/13/2023] [Indexed: 12/17/2023] Open
Abstract
It has been 70 years since Barbara McClintock discovered transposable elements (TE), and the mechanistic studies and functional applications of transposable elements have been at the forefront of life science research. As an essential part of the genome, TEs have been discovered in most species of prokaryotes and eukaryotes, and the relative proportion of the total genetic sequence they comprise gradually increases with the expansion of the genome. In humans, TEs account for about 40% of the genome and are deeply involved in gene regulation, chromosome structure maintenance, inflammatory response, and the etiology of genetic and non-genetic diseases. In-depth functional studies of TEs in mammalian cells and the human body have led to a greater understanding of these fundamental biological processes. At the same time, as a potent mutagen and efficient genome editing tool, TEs have been transformed into biological tools critical for developing new techniques. By controlling the random insertion of TEs into the genome to change the phenotype in cells and model organisms, critical proteins of many diseases have been systematically identified. Exploiting the TE's highly efficient in vitro insertion activity has driven the development of cutting-edge sequencing technologies. Recently, a new technology combining CRISPR with TEs was reported, which provides a novel targeted insertion system to both academia and industry. We suggest that interrogating biological processes that generally depend on the actions of TEs with TEs-derived genetic tools is a very efficient strategy. For example, excessive activation of TEs is an essential factor in the occurrence of cancer in humans. As potent mutagens, TEs have also been used to unravel the key regulatory elements and mechanisms of carcinogenesis. Through this review, we aim to effectively combine the traditional views of TEs with recent research progress, systematically link the mechanistic discoveries of TEs with the technological developments of TE-based tools, and provide a comprehensive approach and understanding for researchers in different fields.
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Affiliation(s)
- Mei Han
- Guangzhou National Laboratory, Guangzhou, China
| | - Matthew H. Perkins
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Leonardo Santana Novaes
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Tao Xu
- Guangzhou National Laboratory, Guangzhou, China
| | - Hao Chang
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, United States
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5
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Balouchi M, Huang SH, McGrath SL, Kobryn K. The telomere resolvase, TelA, utilizes an underwound pre-cleavage intermediate to promote hairpin telomere formation. PLoS One 2023; 18:e0294732. [PMID: 38019799 PMCID: PMC10686437 DOI: 10.1371/journal.pone.0294732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 11/06/2023] [Indexed: 12/01/2023] Open
Abstract
The telomere resolvase, TelA, forms the hairpin telomeres of the linear chromosome of Agrobacterium tumefaciens in a process referred to as telomere resolution. Telomere resolution is a unique DNA cleavage and rejoining reaction that resolves replicated telomere junctions into a pair of hairpin telomeres. Telomere resolvases utilize a reaction mechanism with similarities to that of topoisomerase-IB enzymes and tyrosine recombinases. The reaction proceeds without the need for high-energy cofactors due to the use of a covalent, enzyme-cleaved DNA intermediate that stores the bond energy of the cleaved bonds in 3'-phosphotyrosyl linkages. The cleaved DNA strands are then refolded into a hairpin conformation and the 5'-OH ends of the refolded strands attack the 3'-phosphotyrosine linkages in order to rejoin the DNA strands into hairpin telomeres. Because this kind of reaction mechanism is, in principle, reversible it is unclear how TelA controls the direction of the reaction and propels the reaction to completion. We present evidence that TelA forms and/or stabilizes a pre-cleavage intermediate that features breakage of the four central basepairs between the scissile phosphates prior to DNA cleavage to help propel the reaction forwards, thus preventing abortive cleavage and rejoining cycles that regenerate the substrate DNA. We identify eight TelA sidechains, located in the hairpin-binding module and catalytic domains of TelA, implicated in this process. These mutants were deficient for telomere resolution on parental replicated telomere junctions but were rescued by introduction of substrate modifications that mimic unwinding of the DNA between the scissile phosphates.
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Affiliation(s)
- Mahrokh Balouchi
- Dept. of Biochemistry, Microbiology & Immunology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Shu Hui Huang
- Dept. of Biochemistry, Microbiology & Immunology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Siobhan L. McGrath
- The Global Institute for Food Security, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Kerri Kobryn
- Dept. of Biochemistry, Microbiology & Immunology, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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6
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Martin EC, Le Targa L, Tsakou-Ngouafo L, Fan TP, Lin CY, Xiao J, Huang Z, Yuan S, Xu A, Su YH, Petrescu AJ, Pontarotti P, Schatz DG. Insights into RAG Evolution from the Identification of "Missing Link" Family A RAGL Transposons. Mol Biol Evol 2023; 40:msad232. [PMID: 37850912 PMCID: PMC10629977 DOI: 10.1093/molbev/msad232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/28/2023] [Accepted: 10/10/2023] [Indexed: 10/19/2023] Open
Abstract
A series of "molecular domestication" events are thought to have converted an invertebrate RAG-like (RAGL) transposase into the RAG1-RAG2 (RAG) recombinase, a critical enzyme for adaptive immunity in jawed vertebrates. The timing and order of these events are not well understood, in part because of a dearth of information regarding the invertebrate RAGL-A transposon family. In contrast to the abundant and divergent RAGL-B transposon family, RAGL-A most closely resembles RAG and is represented by a single orphan RAG1-like (RAG1L) gene in the genome of the hemichordate Ptychodera flava (PflRAG1L-A). Here, we provide evidence for the existence of complete RAGL-A transposons in the genomes of P. flava and several echinoderms. The predicted RAG1L-A and RAG2L-A proteins encoded by these transposons intermingle sequence features of jawed vertebrate RAG and RAGL-B transposases, leading to a prediction of DNA binding, catalytic, and transposition activities that are a hybrid of RAG and RAGL-B. Similarly, the terminal inverted repeats (TIRs) of the RAGL-A transposons combine features of both RAGL-B transposon TIRs and RAG recombination signal sequences. Unlike all previously described RAG2L proteins, RAG2L-A proteins contain an acidic hinge region, which we demonstrate is capable of efficiently inhibiting RAG-mediated transposition. Our findings provide evidence for a critical intermediate in RAG evolution and argue that certain adaptations thought to be specific to jawed vertebrates (e.g. the RAG2 acidic hinge) actually arose in invertebrates, thereby focusing attention on other adaptations as the pivotal steps in the completion of RAG domestication in jawed vertebrates.
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Affiliation(s)
- Eliza C Martin
- Department of Immunobiology, Yale School of Medicine, New Haven, CT 06520-8011, USA
| | - Lorlane Le Targa
- Aix-Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille 13005, France
| | - Louis Tsakou-Ngouafo
- Aix-Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille 13005, France
| | - Tzu-Pei Fan
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Che-Yi Lin
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Jianxiong Xiao
- Department of Immunobiology, Yale School of Medicine, New Haven, CT 06520-8011, USA
| | - Ziwen Huang
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Shaochun Yuan
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Anlong Xu
- State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Yi-Hsien Su
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Andrei-Jose Petrescu
- Department of Bioinformatics and Structural Biochemistry, Institute of Biochemistry of the Romanian Academy, 060031 Bucharest, Romania
| | - Pierre Pontarotti
- Aix-Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille 13005, France
- CNRS SNC 5039, 13005 Marseille, France
| | - David G Schatz
- Department of Immunobiology, Yale School of Medicine, New Haven, CT 06520-8011, USA
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7
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Liu L, Cheng Y, Zhang Z, Li J, Geng Y, Li Q, Luo D, Liang L, Liu W, Hu J, Ouyang W. Study on the allosteric activation mechanism of SHP2 via elastic network models and neural relational inference molecular dynamics simulation. Phys Chem Chem Phys 2023; 25:23588-23601. [PMID: 37621251 DOI: 10.1039/d3cp02795c] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
As a ubiquitous protein tyrosine phosphatase, SHP2 is involved in PD-1/PD-L1 mediated tumor immune escape and undergoes substantial conformational changes. Therefore, it is considered an ideal target for tumor intervention. However, the allosteric mechanisms of SHP2 binding PD-1 intracellular ITIM/ITSM phosphopeptides remain unclear, which greatly hinders the development of novel structure-based anticancer allosteric inhibitors. In this work, the open and closed structural models of SHP2 are first constructed based on this knowledge; next their motion modes are investigated via elastic network models such as the Gaussian network model (GNM), anisotropic network model (ANM) and adaptive anisotropic network model (aANM); and finally, a possible allosteric signaling pathway is proposed using a neural relational inference molecular dynamics (NRI-MD) simulation embedded with an artificial intelligence (AI) strategy. In GNM and ANM, the N-SH2, C-SH2 and PTP domains all exhibit distinct dynamics partitions, and the N-SH2/C-SH2 regions show a rigid rotation relative to PTP. According to a series of intermediate snapshots given by aANM, N-SH2 is first identified with pY223 specifically, inducing a D'E-loop to change from β-sheets to random coils, and then, C-SH2 serves as a fulcrum to drive N-SH2 to rotate 110° completely away from the original active sites of PTP. Finally, a possible allosteric signaling-transfer path for SHP2, namely R220-R138-T108-R32, is proposed based on NRI-MD sampling. This work provides a possible allosteric mechanism of SHP2, which is helpful for the following design of novel allosteric inhibitors and is expected to be used in clinical synergies with PD-1 monoclonal antibody.
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Affiliation(s)
- Ling Liu
- Department of Thoracic Oncology, Affiliated Cancer Hospital, Guizhou Medical University, Guiyang, China.
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, China
| | - Yan Cheng
- Breast Disease Center, Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610000, China
| | - Zhigang Zhang
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, China
| | - Jing Li
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, China
| | - Yichao Geng
- Department of Thoracic Oncology, Affiliated Cancer Hospital, Guizhou Medical University, Guiyang, China.
| | - Qingsong Li
- Department of Thoracic Oncology, Affiliated Cancer Hospital, Guizhou Medical University, Guiyang, China.
| | - Daxian Luo
- Department of Thoracic Oncology, Affiliated Cancer Hospital, Guizhou Medical University, Guiyang, China.
| | - Li Liang
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, China
| | - Wei Liu
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, China
| | - Jianping Hu
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, China
| | - Weiwei Ouyang
- Department of Thoracic Oncology, Affiliated Cancer Hospital, Guizhou Medical University, Guiyang, China.
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8
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Martin EC, Le Targa L, Tsakou-Ngouafo L, Fan TP, Lin CY, Xiao J, Su YH, Petrescu AJ, Pontarotti P, Schatz DG. Insights into RAG evolution from the identification of "missing link" family A RAGL transposons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.20.553239. [PMID: 37645967 PMCID: PMC10462144 DOI: 10.1101/2023.08.20.553239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
A series of "molecular domestication" events are thought to have converted an invertebrate RAG-like (RAGL) transposase into the RAG1-RAG2 (RAG) recombinase, a critical enzyme for adaptive immunity in jawed vertebrates. The timing and order of these events is not well understood, in part because of a dearth of information regarding the invertebrate RAGL-A transposon family. In contrast to the abundant and divergent RAGL-B transposon family, RAGL-A most closely resembles RAG and is represented by a single orphan RAG1-like (RAG1L) gene in the genome of the hemichordate Ptychodera flava (PflRAG1L-A). Here, we provide evidence for the existence of complete RAGL-A transposons in the genomes of P. flava and several echinoderms. The predicted RAG1L-A and RAG2L-A proteins encoded by these transposons intermingle sequence features of jawed vertebrate RAG and RAGL-B transposases, leading to a prediction of DNA binding, catalytic, and transposition activities that are a hybrid of RAG and RAGL-B. Similarly, the terminal inverted repeats (TIRs) of the RAGL-A transposons combine features of both RAGL-B transposon TIRs and RAG recombination signal sequences. Unlike all previously described RAG2L proteins, PflRAG2L-A and echinoderm RAG2L-A contain an acidic hinge region, which we demonstrate is capable of efficiently inhibiting RAG-mediated transposition. Our findings provide evidence for a critical intermediate in RAG evolution and argue that certain adaptations thought to be specific to jawed vertebrates (e.g., the RAG2 acidic hinge) actually arose in invertebrates, thereby focusing attention on other adaptations as the pivotal steps in the completion of RAG domestication in jawed vertebrates.
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Affiliation(s)
- Eliza C. Martin
- Department of Immunobiology, Yale School of Medicine, 300 Cedar Street, Box 208011, New Haven, CT, 06520-8011, United States
| | - Lorlane Le Targa
- Aix-Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille France
| | - Louis Tsakou-Ngouafo
- Aix-Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille France
| | - Tzu-Pei Fan
- Institute of Cellular and Organismic Biology, Academia Sinica, 128 Academia Rd., Sec. 2, Nankang, Taipei 11529, Taiwan
| | - Che-Yi Lin
- Institute of Cellular and Organismic Biology, Academia Sinica, 128 Academia Rd., Sec. 2, Nankang, Taipei 11529, Taiwan
| | - Jianxiong Xiao
- Department of Immunobiology, Yale School of Medicine, 300 Cedar Street, Box 208011, New Haven, CT, 06520-8011, United States
| | - Yi Hsien Su
- Institute of Cellular and Organismic Biology, Academia Sinica, 128 Academia Rd., Sec. 2, Nankang, Taipei 11529, Taiwan
| | - Andrei-Jose Petrescu
- Department of Bioinformatics and Structural Biochemistry, Institute of Biochemistry of the Romanian Academy, Splaiul Independentei 296, 060031, Bucharest, Romania
| | - Pierre Pontarotti
- Aix-Marseille Université, IRD, APHM, MEPHI, IHU Méditerranée Infection, Marseille France
- CNRS SNC 5039, 13005 Marseille, France
| | - David G. Schatz
- Department of Immunobiology, Yale School of Medicine, 300 Cedar Street, Box 208011, New Haven, CT, 06520-8011, United States
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9
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Lannes L, Furman CM, Hickman AB, Dyda F. Zinc-finger BED domains drive the formation of the active Hermes transpososome by asymmetric DNA binding. Nat Commun 2023; 14:4470. [PMID: 37491363 PMCID: PMC10368747 DOI: 10.1038/s41467-023-40210-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 07/18/2023] [Indexed: 07/27/2023] Open
Abstract
The Hermes DNA transposon is a member of the eukaryotic hAT superfamily, and its transposase forms a ring-shaped tetramer of dimers. Our investigation, combining biochemical, crystallography and cryo-electron microscopy, and in-cell assays, shows that the full-length Hermes octamer extensively interacts with its transposon left-end through multiple BED domains of three Hermes protomers contributed by three dimers explaining the role of the unusual higher-order assembly. By contrast, the right-end is bound to no BED domains at all. Thus, this work supports a model in which Hermes multimerizes to gather enough BED domains to find its left-end among the abundant genomic DNA, facilitating the subsequent interaction with the right-end.
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Affiliation(s)
- Laurie Lannes
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Christopher M Furman
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Alison B Hickman
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Fred Dyda
- 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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10
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Giengkam S, Kullapanich C, Wongsantichon J, Adcox HE, Gillespie JJ, Salje J. Orientia tsutsugamushi: analysis of the mobilome of a highly fragmented and repetitive genome reveals ongoing lateral gene transfer in an obligate intracellular bacterium. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.11.540415. [PMID: 37215039 PMCID: PMC10197636 DOI: 10.1101/2023.05.11.540415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The rickettsial human pathogen Orientia tsutsugamushi (Ot) is an obligate intracellular Gram-negative bacterium with one of the most highly fragmented and repetitive genomes of any organism. Around 50% of its ~2.3 Mb genome is comprised of repetitive DNA that is derived from the highly proliferated Rickettsiales amplified genetic element (RAGE). RAGE is an integrative and conjugative element (ICE) that is present in a single Ot genome in up to 92 copies, most of which are partially or heavily degraded. In this report, we analysed RAGEs in eight fully sequenced Ot genomes and manually curated and reannotated all RAGE-associated genes, including those encoding DNA mobilisation proteins, P-type (vir) and F-type (tra) type IV secretion system (T4SS) components, Ankyrin repeat- and tetratricopeptide repeat-containing effectors, and other piggybacking cargo. Originally, the heavily degraded Ot RAGEs led to speculation that they are remnants of historical ICEs that are no longer active. Our analysis, however, identified two Ot genomes harbouring one or more intact RAGEs with complete F-T4SS genes essential for mediating ICE DNA transfer. As similar ICEs have been identified in unrelated rickettsial species, we assert that RAGEs play an ongoing role in lateral gene transfer within the Rickettsiales. Remarkably, we also identified in several Ot genomes remnants of prophages with no similarity to other rickettsial prophages. Together these findings indicate that, despite their obligate intracellular lifestyle and host range restricted to mites, rodents and humans, Ot genomes are highly dynamic and shaped through ongoing invasions by mobile genetic elements and viruses.
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Affiliation(s)
- Suparat Giengkam
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Chitrasak Kullapanich
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Jantana Wongsantichon
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Haley E. Adcox
- Department of Microbiology and Immunology, Virginia Commonwealth University Medical Center, School of Medicine, Richmond, Virginia, USA
| | - Joseph J. Gillespie
- Department of Microbiology and Immunology, School of Medicine, University of Maryland Baltimore, MD 21201
| | - Jeanne Salje
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Pathology, Department of Biochemistry, Cambridge Institute for Medical Research, University of Cambridge, UK
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11
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Li Q, Zhou L, Qin S, Huang Z, Li B, Liu R, Yang M, Nice EC, Zhu H, Huang C. Proteolysis-targeting chimeras in biotherapeutics: Current trends and future applications. Eur J Med Chem 2023; 257:115447. [PMID: 37229829 DOI: 10.1016/j.ejmech.2023.115447] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 05/02/2023] [Accepted: 05/02/2023] [Indexed: 05/27/2023]
Abstract
The success of inhibitor-based therapeutics is largely constrained by the acquisition of therapeutic resistance, which is partially driven by the undruggable proteome. The emergence of proteolysis targeting chimera (PROTAC) technology, designed for degrading proteins involved in specific biological processes, might provide a novel framework for solving the above constraint. A heterobifunctional PROTAC molecule could structurally connect an E3 ubiquitin ligase ligand with a protein of interest (POI)-binding ligand by chemical linkers. Such technology would result in the degradation of the targeted protein via the ubiquitin-proteasome system (UPS), opening up a novel way of selectively inhibiting undruggable proteins. Herein, we will highlight the advantages of PROTAC technology and summarize the current understanding of the potential mechanisms involved in biotherapeutics, with a particular focus on its application and development where therapeutic benefits over classical small-molecule inhibitors have been achieved. Finally, we discuss how this technology can contribute to developing biotherapeutic drugs, such as antivirals against infectious diseases, for use in clinical practices.
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Affiliation(s)
- Qiong Li
- West China School of Basic Medical Sciences and Forensic Medicine, State Key Laboratory of Biotherapy and Cancer Center, and West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, PR China
| | - Li Zhou
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, 400016, PR China
| | - Siyuan Qin
- West China School of Basic Medical Sciences and Forensic Medicine, State Key Laboratory of Biotherapy and Cancer Center, and West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, PR China
| | - Zhao Huang
- West China School of Basic Medical Sciences and Forensic Medicine, State Key Laboratory of Biotherapy and Cancer Center, and West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, PR China
| | - Bowen Li
- West China School of Basic Medical Sciences and Forensic Medicine, State Key Laboratory of Biotherapy and Cancer Center, and West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, PR China
| | - Ruolan Liu
- School of Basic Medical Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, PR China
| | - Mei Yang
- West China School of Basic Medical Sciences and Forensic Medicine, State Key Laboratory of Biotherapy and Cancer Center, and West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, PR China
| | - Edouard C Nice
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
| | - Huili Zhu
- Department of Reproductive Medicine, Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education, West China Second University Hospital of Sichuan University, Chengdu, 610041, PR China.
| | - Canhua Huang
- West China School of Basic Medical Sciences and Forensic Medicine, State Key Laboratory of Biotherapy and Cancer Center, and West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, PR China; School of Basic Medical Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, PR China.
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12
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Spínola-Amilibia M, Araújo-Bazán L, de la Gándara Á, Berger JM, Arias-Palomo E. IS21 family transposase cleaved donor complex traps two right-handed superhelical crossings. Nat Commun 2023; 14:2335. [PMID: 37087515 PMCID: PMC10122671 DOI: 10.1038/s41467-023-38071-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 04/14/2023] [Indexed: 04/24/2023] Open
Abstract
Transposases are ubiquitous enzymes that catalyze DNA rearrangement events with broad impacts on gene expression, genome evolution, and the spread of drug-resistance in bacteria. Here, we use biochemical and structural approaches to define the molecular determinants by which IstA, a transposase present in the widespread IS21 family of mobile elements, catalyzes efficient DNA transposition. Solution studies show that IstA engages the transposon terminal sequences to form a high-molecular weight complex and promote DNA integration. A 3.4 Å resolution structure of the transposase bound to transposon ends corroborates our biochemical findings and reveals that IstA self-assembles into a highly intertwined tetramer that synapses two supercoiled terminal inverted repeats. The three-dimensional organization of the IstA•DNA cleaved donor complex reveals remarkable similarities with retroviral integrases and classic transposase systems, such as Tn7 and bacteriophage Mu, and provides insights into IS21 transposition.
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Affiliation(s)
- Mercedes Spínola-Amilibia
- Department of Structural & Chemical Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, 28040, Spain
| | - Lidia Araújo-Bazán
- Department of Structural & Chemical Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, 28040, Spain
| | - Álvaro de la Gándara
- Department of Structural & Chemical Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, 28040, Spain
| | - James M Berger
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Ernesto Arias-Palomo
- Department of Structural & Chemical Biology, Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, 28040, Spain.
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13
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Deng S. The origin of genetic and metabolic systems: Evolutionary structuralinsights. Heliyon 2023; 9:e14466. [PMID: 36967965 PMCID: PMC10036676 DOI: 10.1016/j.heliyon.2023.e14466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 02/27/2023] [Accepted: 03/06/2023] [Indexed: 03/16/2023] Open
Abstract
DNA is derived from reverse transcription and its origin is related to reverse transcriptase, DNA polymerase and integrase. The gene structure originated from the evolution of the first RNA polymerase. Thus, an explanation of the origin of the genetic system must also explain the evolution of these enzymes. This paper proposes a polymer structure model, termed the stable complex evolution model, which explains the evolution of enzymes and functional molecules. Enzymes evolved their functions by forming locally tightly packed complexes with specific substrates. A metabolic reaction can therefore be considered to be the result of adaptive evolution in this way when a certain essential molecule is lacking in a cell. The evolution of the primitive genetic and metabolic systems was thus coordinated and synchronized. According to the stable complex model, almost all functional molecules establish binding affinity and specific recognition through complementary interactions, and functional molecules therefore have the nature of being auto-reactive. This is thermodynamically favorable and leads to functional duplication and self-organization. Therefore, it can be speculated that biological systems have a certain tendency to maintain functional stability or are influenced by an inherent selective power. The evolution of dormant bacteria may support this hypothesis, and inherent selectivity can be unified with natural selection at the molecular level.
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Affiliation(s)
- Shaojie Deng
- Chongqing (Fengjie) Municipal Bureau of Planning and Natural Resources, China
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14
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Zhang Y, Tang Y, Sun Z, Jia J, Fang Y, Wan X, Fang D. Tn5 tagments and transposes oligos to single-stranded DNA for strand-specific RNA sequencing. Genome Res 2023; 33:412-426. [PMID: 36958795 PMCID: PMC10078286 DOI: 10.1101/gr.277213.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 02/01/2023] [Indexed: 03/25/2023]
Abstract
Tn5 transposon tagments double-stranded DNA and RNA/DNA hybrids to generate nucleic acids that are ready to be amplified for high-throughput sequencing. The nucleic acid substrates for the Tn5 transposon must be explored to increase the applications of Tn5. Here, we found that the Tn5 transposon can transpose oligos into the 5' end of single-stranded DNA longer than 140 nucleotides. Based on this property of Tn5, we developed a tagmentation-based and ligation-enabled single-stranded DNA sequencing method called TABLE-seq. Through a series of reaction temperature, time, and enzyme concentration tests, we applied TABLE-seq to strand-specific RNA sequencing, starting with as little as 30 pg of total RNA. Moreover, compared with traditional dUTP-based strand-specific RNA sequencing, this method detects more genes, has a higher strand specificity, and shows more evenly distributed reads across genes. Together, our results provide insights into the properties of Tn5 transposons and expand the applications of Tn5 in cutting-edge sequencing techniques.
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Affiliation(s)
- Yanjun Zhang
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yin Tang
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Zhongxing Sun
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Junqi Jia
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yuan Fang
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xinyi Wan
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Dong Fang
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China;
- Department of Medical Oncology, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, China
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15
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The autism risk factor CHD8 is a chromatin activator in human neurons and functionally dependent on the ERK-MAPK pathway effector ELK1. Sci Rep 2022; 12:22425. [PMID: 36575212 PMCID: PMC9794786 DOI: 10.1038/s41598-022-23614-x] [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: 08/10/2021] [Accepted: 11/02/2022] [Indexed: 12/28/2022] Open
Abstract
The chromodomain helicase DNA-binding protein CHD8 is the most frequently mutated gene in autism spectrum disorder. Despite its prominent disease involvement, little is known about its molecular function in the human brain. CHD8 is a chromatin regulator which binds to the promoters of actively transcribed genes through genomic targeting mechanisms which have yet to be fully defined. By generating a conditional loss-of-function and an endogenously tagged allele in human pluripotent stem cells, we investigated the molecular function and the interaction of CHD8 with chromatin in human neurons. Chromatin accessibility analysis and transcriptional profiling revealed that CHD8 functions as a transcriptional activator at its target genes in human neurons. Furthermore, we found that CHD8 chromatin targeting is cell context-dependent. In human neurons, CHD8 preferentially binds at ETS motif-enriched promoters. This enrichment is particularly prominent on the promoters of genes whose expression significantly changes upon the loss of CHD8. Indeed, among the ETS transcription factors, we identified ELK1 as being most highly correlated with CHD8 expression in primary human fetal and adult cortical neurons and most highly expressed in our stem cell-derived neurons. Remarkably, ELK1 was necessary to recruit CHD8 specifically to ETS motif-containing sites. These findings imply that ELK1 and CHD8 functionally cooperate to regulate gene expression and chromatin states at MAPK/ERK target genes in human neurons. Our results suggest that the MAPK/ERK/ELK1 axis potentially contributes to the pathogenesis caused by CHD8 mutations in human neurodevelopmental disorders.
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16
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Shkumatov AV, Aryanpour N, Oger CA, Goossens G, Hallet BF, Efremov RG. Structural insight into Tn3 family transposition mechanism. Nat Commun 2022; 13:6155. [PMID: 36257990 PMCID: PMC9579193 DOI: 10.1038/s41467-022-33871-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 10/05/2022] [Indexed: 12/24/2022] Open
Abstract
Transposons are diverse mobile genetic elements that play the critical role as genome architects in all domains of life. Tn3 is a widespread family and among the first identified bacterial transposons famed for their contribution to the dissemination of antibiotic resistance. Transposition within this family is mediated by a large TnpA transposase, which facilitates both transposition and target immunity. Howtever, a structural framework required for understanding the mechanism of TnpA transposition is lacking. Here, we describe the cryo-EM structures of TnpA from Tn4430 in the apo form and paired with transposon ends before and after DNA cleavage and strand transfer. We show that TnpA has an unusual architecture and exhibits a family specific regulatory mechanism involving metamorphic refolding of the RNase H-like catalytic domain. The TnpA structure, constrained by a double dimerization interface, creates a peculiar topology that suggests a specific role for the target DNA in transpososome assembly and activation.
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Affiliation(s)
- Alexander V. Shkumatov
- grid.11486.3a0000000104788040Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium ,grid.8767.e0000 0001 2290 8069Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium ,Present Address: Confo Therapeutics, Brussels, Belgium
| | - Nicolas Aryanpour
- grid.7942.80000 0001 2294 713XLouvain Institue of Biomolecular Science and Technology, Université Catholique de Louvain (UCLouvain), Croix du Sud 4/5, 1348 Louvain-la-Neuve, Belgium
| | - Cédric A. Oger
- grid.7942.80000 0001 2294 713XLouvain Institue of Biomolecular Science and Technology, Université Catholique de Louvain (UCLouvain), Croix du Sud 4/5, 1348 Louvain-la-Neuve, Belgium
| | - Gérôme Goossens
- grid.7942.80000 0001 2294 713XLouvain Institue of Biomolecular Science and Technology, Université Catholique de Louvain (UCLouvain), Croix du Sud 4/5, 1348 Louvain-la-Neuve, Belgium ,Present Address: Thermo Fisher Scientific, Seneffe, Belgium
| | - Bernard F. Hallet
- grid.7942.80000 0001 2294 713XLouvain Institue of Biomolecular Science and Technology, Université Catholique de Louvain (UCLouvain), Croix du Sud 4/5, 1348 Louvain-la-Neuve, Belgium
| | - Rouslan G. Efremov
- grid.11486.3a0000000104788040Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium ,grid.8767.e0000 0001 2290 8069Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
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17
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Tenjo-Castaño F, Sofos N, López-Méndez B, Stutzke LS, Fuglsang A, Stella S, Montoya G. Structure of the TnsB transposase-DNA complex of type V-K CRISPR-associated transposon. Nat Commun 2022; 13:5792. [PMID: 36184667 PMCID: PMC9527255 DOI: 10.1038/s41467-022-33504-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 09/20/2022] [Indexed: 11/17/2022] Open
Abstract
CRISPR-associated transposons (CASTs) are mobile genetic elements that co-opted CRISPR-Cas systems for RNA-guided transposition. Here we present the 2.4 Å cryo-EM structure of the Scytonema hofmannii (sh) TnsB transposase from Type V-K CAST, bound to the strand transfer DNA. The strand transfer complex displays an intertwined pseudo-symmetrical architecture. Two protomers involved in strand transfer display a catalytically competent active site composed by DDE residues, while other two, which play a key structural role, show active sites where the catalytic residues are not properly positioned for phosphodiester hydrolysis. Transposon end recognition is accomplished by the NTD1/2 helical domains. A singular in trans association of NTD1 domains of the catalytically competent subunits with the inactive DDE domains reinforces the assembly. Collectively, the structural features suggest that catalysis is coupled to protein-DNA assembly to secure proper DNA integration. DNA binding residue mutants reveal that lack of specificity decreases activity, but it could increase transposition in some cases. Our structure sheds light on the strand transfer reaction of DDE transposases and offers new insights into CAST transposition. The cryo-EM structure of the type VK CRISPR-associated TnsB transposase sheds light onto RNA-guided transposition, providing new possibilities to redesign CRISPR-associated transposon systems.
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Affiliation(s)
- Francisco Tenjo-Castaño
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, 2200, Copenhagen, Denmark
| | - Nicholas Sofos
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, 2200, Copenhagen, Denmark
| | - Blanca López-Méndez
- Protein Purification and Characterisation Facility, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, 2200, Copenhagen, Denmark
| | - Luisa S Stutzke
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, 2200, Copenhagen, Denmark
| | - Anders Fuglsang
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, 2200, Copenhagen, Denmark
| | - Stefano Stella
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, 2200, Copenhagen, Denmark.,Twelve Bio ApS, Ole Maaløes Vej 3, 2200, Copenhagen, Denmark
| | - Guillermo Montoya
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, 2200, Copenhagen, Denmark.
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18
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Riggs P, Blundell-Hunter G, Hagelberger J, Ren G, Ettwiller L, Berkmen M. Insertion Specificity of the hATx-6 Transposase of Hydra magnipapillata. Front Mol Biosci 2022; 8:734154. [PMID: 34988112 DOI: 10.3389/fmolb.2021.734154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 11/10/2021] [Indexed: 01/22/2023] Open
Abstract
Transposable elements (TE) are mobile genetic elements, present in all domains of life. They commonly encode a single transposase enzyme, that performs the excision and reintegration reactions, and these enzymes have been used in mutagenesis and creation of next-generation sequencing libraries. All transposases have some bias in the DNA sequence they bind to when reintegrating the TE DNA. We sought to identify a transposase that showed minimal sequence bias and could be produced recombinantly, using information from the literature and a novel bioinformatic analysis, resulting in the selection of the hATx-6 transposase from Hydra vulgaris (aka Hydra magnipapillata) for further study. This transposase was tested and shown to be active both in vitro and in vivo, and we were able to demonstrate very low sequence bias in its integration preference. This transposase could be an excellent candidate for use in biotechnology, such as the creation of next-generation sequencing libraries.
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Affiliation(s)
- Paul Riggs
- New England Biolabs, Ipswich, MA, United States
| | | | | | - Guoping Ren
- New England Biolabs, Ipswich, MA, United States
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19
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Duan H, Zhou Y, Shi X, Luo Q, Gao J, Liang L, Liu W, Peng L, Deng D, Hu J. Allosteric and transport modulation of human concentrative nucleoside transporter 3 at the atomic scale. Phys Chem Chem Phys 2021; 23:25401-25413. [PMID: 34751688 DOI: 10.1039/d1cp03756k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Nucleosides are important precursors of nucleotide synthesis in cells, and nucleoside transporters play an important role in many physiological processes by mediating transmembrane transport and absorption. During nucleoside transport, such proteins undergo a significant conformational transition between the outward- and inward-facing states, which leads to alternating access of the substrate-binding site to either side of the membrane. In this work, a variety of molecular simulation methods have been applied to comparatively investigate the motion modes of human concentrative nucleoside transporter 3 (hCNT3) in three states, as well as global and local cavity conformational changes; and finally, a possible elevator-like transport mechanism consistent with experimental data was proposed. The results of the Gaussian network model (GNM) and anisotropic network model (ANM) show that hCNT3 as a whole tends to contract inwards and shift towards a membrane inside, exhibiting an allosteric process that is more energetically favorable than the rigid conversion. To reveal the complete allosteric process of hCNT3 in detail, a series of intermediate conformations were obtained by an adaptive anisotropic network model (aANM). One of the simulated intermediate states is similar to that of a crystal structure, which indicates that the allosteric process is reliable; the state with lower energy is slightly inclined to the inward-facing structure rather than the expected intermediate crystal structure. The final HOLE analysis showed that except for the outward-facing state, the transport channels were gradually enlarged, which was conductive to the directional transport of nucleosides. Our work provides a theoretical basis for the multistep elevator-like transportation mechanism of nucleosides, which helps to further understand the dynamic recognition between nucleoside substrates and hCNT3 as well as the design of nucleoside anticancer drugs.
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Affiliation(s)
- Huaichuan Duan
- School of Pharmacy, Sichuan Industrial Institute of Antibiotics, Chengdu University, Chengdu, China.
| | - Yanxia Zhou
- Key Laboratory of Birth Defects and Related Disease of Women and Children of MOE, State Key Laboratory of Biotherapy, Department of Obstetrics, West China Second Hospital, Sichuan University, Chengdu, China.
| | - Xiaodong Shi
- School of Pharmacy, Sichuan Industrial Institute of Antibiotics, Chengdu University, Chengdu, China.
| | - Qing Luo
- School of Pharmacy, Sichuan Industrial Institute of Antibiotics, Chengdu University, Chengdu, China.
| | - Jiaxing Gao
- School of Pharmacy, Sichuan Industrial Institute of Antibiotics, Chengdu University, Chengdu, China.
| | - Li Liang
- School of Pharmacy, Sichuan Industrial Institute of Antibiotics, Chengdu University, Chengdu, China.
| | - Wei Liu
- School of Pharmacy, Sichuan Industrial Institute of Antibiotics, Chengdu University, Chengdu, China.
| | - Lianxin Peng
- School of Pharmacy, Sichuan Industrial Institute of Antibiotics, Chengdu University, Chengdu, China.
| | - Dong Deng
- Key Laboratory of Birth Defects and Related Disease of Women and Children of MOE, State Key Laboratory of Biotherapy, Department of Obstetrics, West China Second Hospital, Sichuan University, Chengdu, China.
| | - Jianping Hu
- School of Pharmacy, Sichuan Industrial Institute of Antibiotics, Chengdu University, Chengdu, China.
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20
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Zhang H, Lu T, Liu S, Yang J, Sun G, Cheng T, Xu J, Chen F, Yen K. Comprehensive understanding of Tn5 insertion preference improves transcription regulatory element identification. NAR Genom Bioinform 2021; 3:lqab094. [PMID: 34729473 PMCID: PMC8557372 DOI: 10.1093/nargab/lqab094] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 09/20/2021] [Accepted: 09/29/2021] [Indexed: 12/11/2022] Open
Abstract
Tn5 transposase, which can efficiently tagment the genome, has been widely adopted as a molecular tool in next-generation sequencing, from short-read sequencing to more complex methods such as assay for transposase-accessible chromatin using sequencing (ATAC-seq). Here, we systematically map Tn5 insertion characteristics across several model organisms, finding critical parameters that affect its insertion. On naked genomic DNA, we found that Tn5 insertion is not uniformly distributed or random. To uncover drivers of these biases, we used a machine learning framework, which revealed that DNA shape cooperatively works with DNA motif to affect Tn5 insertion preference. These intrinsic insertion preferences can be modeled using nucleotide dependence information from DNA sequences, and we developed a computational pipeline to correct for these biases in ATAC-seq data. Using our pipeline, we show that bias correction improves the overall performance of ATAC-seq peak detection, recovering many potential false-negative peaks. Furthermore, we found that these peaks are bound by transcription factors, underscoring the biological relevance of capturing this additional information. These findings highlight the benefits of an improved understanding and precise correction of Tn5 insertion preference.
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Affiliation(s)
- Houyu Zhang
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020, China
| | - Ting Lu
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020, China
| | - Shan Liu
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020, China
| | - Jianyu Yang
- Department of Developmental Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Guohuan Sun
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020, China
| | - Tao Cheng
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020, China
| | - Jin Xu
- Division of Cell, Developmental and Integrative Biology, School of Medicine, South China University of Technology, Guangzhou 510006, China
| | - Fangyao Chen
- Department of Epidemiology and Biostatistics, School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, China
| | - Kuangyu Yen
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020, China
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21
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The large bat Helitron DNA transposase forms a compact monomeric assembly that buries and protects its covalently bound 5'-transposon end. Mol Cell 2021; 81:4271-4286.e4. [PMID: 34403695 DOI: 10.1016/j.molcel.2021.07.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 07/23/2021] [Accepted: 07/23/2021] [Indexed: 12/22/2022]
Abstract
Helitrons are widespread eukaryotic DNA transposons that have significantly contributed to genome variability and evolution, in part because of their distinctive, replicative rolling-circle mechanism, which often mobilizes adjacent genes. Although most eukaryotic transposases form oligomers and use RNase H-like domains to break and rejoin double-stranded DNA (dsDNA), Helitron transposases contain a single-stranded DNA (ssDNA)-specific HUH endonuclease domain. Here, we report the cryo-electron microscopy structure of a Helitron transposase bound to the 5'-transposon end, providing insight into its multidomain architecture and function. The monomeric transposase forms a tightly packed assembly that buries the covalently attached cleaved end, protecting it until the second end becomes available. The structure reveals unexpected architectural similarity to TraI, a bacterial relaxase that also catalyzes ssDNA movement. The HUH active site suggests how two juxtaposed tyrosines, a feature of many replication initiators that use HUH nucleases, couple the conformational shift of an α-helix to control strand cleavage and ligation reactions.
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22
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Abstract
It has been just over 10 years since the initial description of transposase-based methods to prepare high-throughput sequencing libraries, or "tagmentation," in which a hyperactive transposase is used to simultaneously fragment target DNA and append universal adapter sequences. Tagmentation effectively replaced a series of processing steps in traditional workflows with one single reaction. It is the simplicity, coupled with the high efficiency of tagmentation, that has made it a favored means of sequencing library construction and fueled a diverse range of adaptations to assay a variety of molecular properties. In recent years, this has been centered in the single-cell space with a catalog of tagmentation-based assays that have been developed, covering a substantial swath of the regulatory landscape. To date, there have been a number of excellent reviews on single-cell technologies structured around the molecular properties that can be profiled. This review is instead framed around the central components and properties of tagmentation and how they have enabled the development of innovative molecular tools to probe the regulatory landscape of single cells. Furthermore, the granular specifics on cell throughput or richness of data provided by the extensive list of individual technologies are not discussed. Such metrics are rapidly changing and highly sample specific and are better left to studies that directly compare technologies for assays against one another in a rigorously controlled framework. The hope for this review is that, in laying out the diversity of molecular techniques at each stage of these assay platforms, new ideas may arise for others to pursue that will further advance the field of single-cell genomics.
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Affiliation(s)
- Andrew C Adey
- Department of Molecular & Medical Genetics, Knight Cancer Institute, Knight Cardiovascular Institute, Cancer Early Detection Advanced Research Center, Oregon Health and Science University, Portland, Oregon 97239, USA
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23
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Reconstructing and counting genomic fragments through tagmentation-based haploid phasing. Sci Rep 2021; 11:18907. [PMID: 34556684 PMCID: PMC8460729 DOI: 10.1038/s41598-021-97852-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 08/27/2021] [Indexed: 11/16/2022] Open
Abstract
Single-cell sequencing provides a new level of granularity in studying the heterogeneous nature of cancer cells. For some cancers, this heterogeneity is the result of copy number changes of genes within the cellular genomes. The ability to accurately determine such copy number changes is critical in tracing and understanding tumorigenesis. Current single-cell genome sequencing methodologies infer copy numbers based on statistical approaches followed by rounding decimal numbers to integer values. Such methodologies are sample dependent, have varying calling sensitivities which heavily depend on the sample’s ploidy and are sensitive to noise in sequencing data. In this paper we have demonstrated the concept of integer-counting by using a novel bioinformatic algorithm built on our library construction chemistry in order to detect the discrete nature of the genome.
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24
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Dual DNA and protein tagging of open chromatin unveils dynamics of epigenomic landscapes in leukemia. Nat Methods 2021; 18:293-302. [PMID: 33649590 PMCID: PMC8272231 DOI: 10.1038/s41592-021-01077-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 01/20/2021] [Indexed: 02/08/2023]
Abstract
The architecture of chromatin regulates eukaryotic cell states by controlling transcription factor access to sites of gene regulation. Here we describe a dual transposase-peroxidase approach, integrative DNA and protein tagging (iDAPT), which detects both DNA (iDAPT-seq) and protein (iDAPT-MS) associated with accessible regions of chromatin. In addition to direct identification of bound transcription factors, iDAPT enables the inference of their gene regulatory networks, protein interactors and regulation of chromatin accessibility. We applied iDAPT to profile the epigenomic consequences of granulocytic differentiation of acute promyelocytic leukemia, yielding previously undescribed mechanistic insights. Our findings demonstrate the power of iDAPT as a platform for studying the dynamic epigenomic landscapes and their transcription factor components associated with biological phenomena and disease.
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25
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Ubiquitous Selfish Toxin-Antidote Elements in Caenorhabditis Species. Curr Biol 2021; 31:990-1001.e5. [PMID: 33417886 DOI: 10.1016/j.cub.2020.12.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 10/28/2020] [Accepted: 12/09/2020] [Indexed: 11/22/2022]
Abstract
Toxin-antidote elements (TAs) are selfish genetic dyads that spread in populations by selectively killing non-carriers. TAs are common in prokaryotes, but very few examples are known in animals. Here, we report the discovery of maternal-effect TAs in both C. tropicalis and C. briggsae, two distant relatives of C. elegans. In C. tropicalis, multiple TAs combine to cause a striking degree of intraspecific incompatibility: five elements reduce the fitness of >70% of the F2 hybrid progeny of two Caribbean isolates. We identified the genes underlying one of the novel TAs, slow-1/grow-1, and found that its toxin, slow-1, is homologous to nuclear hormone receptors. Remarkably, although previously known TAs act during embryonic development, maternal loading of slow-1 in oocytes specifically slows down larval development, delaying the onset of reproduction by several days. Finally, we found that balancing selection acting on linked, conflicting TAs hampers their ability to spread in populations, leading to more stable genetic incompatibilities. Our findings indicate that TAs are widespread in Caenorhabditis species and target a wide range of developmental processes and that antagonism between them may cause lasting incompatibilities in natural populations. We expect that similar phenomena exist in other animal species.
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26
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Kosek D, Hickman AB, Ghirlando R, He S, Dyda F. Structures of ISCth4 transpososomes reveal the role of asymmetry in copy-out/paste-in DNA transposition. EMBO J 2021; 40:e105666. [PMID: 33006208 PMCID: PMC7780238 DOI: 10.15252/embj.2020105666] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/07/2020] [Accepted: 09/10/2020] [Indexed: 01/23/2023] Open
Abstract
Copy-out/paste-in transposition is a major bacterial DNA mobility pathway. It contributes significantly to the emergence of antibiotic resistance, often by upregulating expression of downstream genes upon integration. Unlike other transposition pathways, it requires both asymmetric and symmetric strand transfer steps. Here, we report the first structural study of a copy-out/paste-in transposase and demonstrate its ability to catalyze all pathway steps in vitro. X-ray structures of ISCth4 transposase, a member of the IS256 family of insertion sequences, bound to DNA substrates corresponding to three sequential steps in the reaction reveal an unusual asymmetric dimeric transpososome. During transposition, an array of N-terminal domains binds a single transposon end while the catalytic domain moves to accommodate the varying substrates. These conformational changes control the path of DNA flanking the transposon end and the generation of DNA-binding sites. Our results explain the asymmetric outcome of the initial strand transfer and show how DNA binding is modulated by the asymmetric transposase to allow the capture of a second transposon end and to integrate a circular intermediate.
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Affiliation(s)
- Dalibor Kosek
- Laboratory of Molecular BiologyNational Institute of Diabetes and Digestive and Kidney DiseasesNational Institutes of HealthBethesdaMDUSA
| | - Alison B Hickman
- Laboratory of Molecular BiologyNational Institute of Diabetes and Digestive and Kidney DiseasesNational Institutes of HealthBethesdaMDUSA
| | - Rodolfo Ghirlando
- Laboratory of Molecular BiologyNational Institute of Diabetes and Digestive and Kidney DiseasesNational Institutes of HealthBethesdaMDUSA
| | - Susu He
- Laboratory of Molecular BiologyNational Institute of Diabetes and Digestive and Kidney DiseasesNational Institutes of HealthBethesdaMDUSA
- Present address:
State Key Laboratory of Pharmaceutical BiotechnologyMedical School of Nanjing UniversityNanjingJiangsuChina
| | - Fred Dyda
- Laboratory of Molecular BiologyNational Institute of Diabetes and Digestive and Kidney DiseasesNational Institutes of HealthBethesdaMDUSA
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27
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Li N, Jin K, Bai Y, Fu H, Liu L, Liu B. Tn5 Transposase Applied in Genomics Research. Int J Mol Sci 2020; 21:ijms21218329. [PMID: 33172005 PMCID: PMC7664229 DOI: 10.3390/ijms21218329] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/24/2020] [Accepted: 10/26/2020] [Indexed: 11/28/2022] Open
Abstract
The development of high-throughput sequencing (next-generation sequencing technology (NGS)) and the continuous increase in experimental throughput require the upstream sample processing steps of NGS to be as simple as possible to improve the efficiency of the entire NGS process. The transposition system has fast “cut and paste” and “copy and paste” functions, and has been innovatively applied to the NGS field. For example, the Assay for Transposase-Accessible Chromatin with high throughput sequencing (ATAC-Seq) uses high-throughput sequencing to detect chromatin regions accessible by Tn5 transposase. Linear Amplification via Transposon Insertion (LIANTI) uses Tn5 transposase for linear amplification, haploid typing, and structural variation detection. Not only is it efficient and simple, it effectively shortens the time for NGS sample library construction, realizes large-scale and rapid sequencing, improves sequencing resolution, and can be flexibly modified for more technological innovation.
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Affiliation(s)
- Niannian Li
- College of Life Sciences, Nankai University, Tianjin 300071, China; (N.L.); (K.J.); (H.F.)
| | - Kairang Jin
- College of Life Sciences, Nankai University, Tianjin 300071, China; (N.L.); (K.J.); (H.F.)
| | - Yanmin Bai
- State Key Laboratory of Silkworm Genome Biology, College of Biotechnology, Southwest University, Chongqing 400700, China;
| | - Haifeng Fu
- College of Life Sciences, Nankai University, Tianjin 300071, China; (N.L.); (K.J.); (H.F.)
| | - Lin Liu
- College of Life Sciences, Nankai University, Tianjin 300071, China; (N.L.); (K.J.); (H.F.)
- Correspondence: (L.L.); (B.L.)
| | - Bin Liu
- School of Life Sciences, Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, Tsinghua University, Beijing 100084, China
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300071, China
- Correspondence: (L.L.); (B.L.)
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28
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Kim J, Lee GE, Shin CG. Foamy Virus Integrase in Development of Viral Vector for Gene Therapy. J Microbiol Biotechnol 2020; 30:1273-1281. [PMID: 32699199 PMCID: PMC9728412 DOI: 10.4014/jmb.2003.03046] [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: 03/23/2020] [Revised: 06/29/2020] [Accepted: 07/14/2020] [Indexed: 12/15/2022]
Abstract
Due to the broad host suitability of viral vectors and their high gene delivery capacity, many researchers are focusing on viral vector-mediated gene therapy. Among the retroviruses, foamy viruses have been considered potential gene therapy vectors because of their non-pathogenicity. To date, the prototype foamy virus is the only retrovirus that has a high-resolution structure of intasomes, nucleoprotein complexes formed by integrase, and viral DNA. The integration of viral DNA into the host chromosome is an essential step for viral vector development. This process is mediated by virally encoded integrase, which catalyzes unique chemical reactions. Additionally, recent studies on foamy virus integrase elucidated the catalytic functions of its three distinct domains and their effect on viral pathogenicity. This review focuses on recent advancements in biochemical, structural, and functional studies of foamy virus integrase for gene therapy vector research.
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Affiliation(s)
- Jinsun Kim
- Department of Systems Biotechnology, Chung-Ang University, Anseong 17546, Republic of Korea
| | - Ga-Eun Lee
- Department of Systems Biotechnology, Chung-Ang University, Anseong 17546, Republic of Korea
| | - Cha-Gyun Shin
- Department of Systems Biotechnology, Chung-Ang University, Anseong 17546, Republic of Korea,Corresponding author Phone: +82-31-670-3067 Fax: +82-31-675-3108 E-mail:
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29
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Structural basis of seamless excision and specific targeting by piggyBac transposase. Nat Commun 2020; 11:3446. [PMID: 32651359 PMCID: PMC7351741 DOI: 10.1038/s41467-020-17128-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 06/02/2020] [Indexed: 12/16/2022] Open
Abstract
The piggyBac DNA transposon is used widely in genome engineering applications. Unlike other transposons, its excision site can be precisely repaired without leaving footprints and it integrates specifically at TTAA tetranucleotides. We present cryo-EM structures of piggyBac transpososomes: a synaptic complex with hairpin DNA intermediates and a strand transfer complex capturing the integration step. The results show that the excised TTAA hairpin intermediate and the TTAA target adopt essentially identical conformations, providing a mechanistic link connecting the two unique properties of piggyBac. The transposase forms an asymmetric dimer in which the two central domains synapse the ends while two C-terminal domains form a separate dimer that contacts only one transposon end. In the strand transfer structure, target DNA is severely bent and the TTAA target is unpaired. In-cell data suggest that asymmetry promotes synaptic complex formation, and modifying ends with additional transposase binding sites stimulates activity.
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30
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Kesselring L, Miskey C, Zuliani C, Querques I, Kapitonov V, Laukó A, Fehér A, Palazzo A, Diem T, Lustig J, Sebe A, Wang Y, Dinnyés A, Izsvák Z, Barabas O, Ivics Z. A single amino acid switch converts the Sleeping Beauty transposase into an efficient unidirectional excisionase with utility in stem cell reprogramming. Nucleic Acids Res 2020; 48:316-331. [PMID: 31777924 PMCID: PMC6943129 DOI: 10.1093/nar/gkz1119] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 11/07/2019] [Accepted: 11/22/2019] [Indexed: 12/26/2022] Open
Abstract
The Sleeping Beauty (SB) transposon is an advanced tool for genetic engineering and a useful model to investigate cut-and-paste DNA transposition in vertebrate cells. Here, we identify novel SB transposase mutants that display efficient and canonical excision but practically unmeasurable genomic re-integration. Based on phylogenetic analyses, we establish compensating amino acid replacements that fully rescue the integration defect of these mutants, suggesting epistasis between these amino acid residues. We further show that the transposons excised by the exc+/int− transposase mutants form extrachromosomal circles that cannot undergo a further round of transposition, thereby representing dead-end products of the excision reaction. Finally, we demonstrate the utility of the exc+/int− transposase in cassette removal for the generation of reprogramming factor-free induced pluripotent stem cells. Lack of genomic integration and formation of transposon circles following excision is reminiscent of signal sequence removal during V(D)J recombination, and implies that cut-and-paste DNA transposition can be converted to a unidirectional process by a single amino acid change.
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Affiliation(s)
- Lisa Kesselring
- Transposition and Genome Engineering, Division of Medical Biotechnology, Paul Ehrlich Institute, Langen, Germany
| | - Csaba Miskey
- Transposition and Genome Engineering, Division of Medical Biotechnology, Paul Ehrlich Institute, Langen, Germany
| | - Cecilia Zuliani
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg 69117, Germany
| | - Irma Querques
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg 69117, Germany
| | - Vladimir Kapitonov
- Transposition and Genome Engineering, Division of Medical Biotechnology, Paul Ehrlich Institute, Langen, Germany
| | | | - Anita Fehér
- BioTalentum Ltd, Gödöllő, 2100 Gödöllő, Hungary
| | - Antonio Palazzo
- Department of Biology, University of Bari 'Aldo Moro', Italy
| | - Tanja Diem
- Transposition and Genome Engineering, Division of Medical Biotechnology, Paul Ehrlich Institute, Langen, Germany
| | - Janna Lustig
- Transposition and Genome Engineering, Division of Medical Biotechnology, Paul Ehrlich Institute, Langen, Germany
| | - Attila Sebe
- Transposition and Genome Engineering, Division of Medical Biotechnology, Paul Ehrlich Institute, Langen, Germany
| | - Yongming Wang
- Mobile DNA, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | | | - Zsuzsanna Izsvák
- Mobile DNA, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Orsolya Barabas
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg 69117, Germany
| | - Zoltán Ivics
- Transposition and Genome Engineering, Division of Medical Biotechnology, Paul Ehrlich Institute, Langen, Germany
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31
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Cutting antiparallel DNA strands in a single active site. Nat Struct Mol Biol 2020; 27:119-126. [PMID: 32015552 PMCID: PMC7015813 DOI: 10.1038/s41594-019-0363-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 12/13/2019] [Indexed: 01/17/2023]
Abstract
A single enzyme active site that catalyzes multiple reactions is a well-established biochemical theme, but how one nuclease site cleaves both DNA strands of a double helix has not been well understood. In analyzing site-specific DNA cleavage by the mammalian RAG1-RAG2 recombinase, which initiates V(D)J recombination, we find that the active site is reconfigured for the two consecutive reactions and the DNA double helix adopts drastically different structures. For initial nicking of the DNA, a locally unwound and unpaired DNA duplex forms a zipper via alternating interstrand base stacking, rather than melting as generally thought. The second strand cleavage and formation of a hairpin-DNA product requires a global scissor-like movement of protein and DNA, delivering the scissile phosphate into the rearranged active site.
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32
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Abstract
RNA sequencing is widely used to measure gene expression in biomedical research; therefore, improvements in the simplicity and accuracy of the technology are desirable. All existing RNA sequencing methods rely on the conversion of RNA into double-stranded DNA through reverse transcription followed by second-strand synthesis. The latter step requires additional enzymes and purification, and introduces sequence-dependent bias. Here, we show that Tn5 transposase, which randomly binds and cuts double-stranded DNA, can directly fragment and prime the RNA/DNA heteroduplexes generated by reverse transcription. The primed fragments are then subject to PCR amplification. This provides an approach for simple and accurate RNA characterization and quantification. Transcriptome profiling by RNA sequencing (RNA-seq) has been widely used to characterize cellular status, but it relies on second-strand complementary DNA (cDNA) synthesis to generate initial material for library preparation. Here we use bacterial transposase Tn5, which has been increasingly used in various high-throughput DNA analyses, to construct RNA-seq libraries without second-strand synthesis. We show that Tn5 transposome can randomly bind RNA/DNA heteroduplexes and add sequencing adapters onto RNA directly after reverse transcription. This method, Sequencing HEteRo RNA-DNA-hYbrid (SHERRY), is versatile and scalable. SHERRY accepts a wide range of starting materials, from bulk RNA to single cells. SHERRY offers a greatly simplified protocol and produces results with higher reproducibility and GC uniformity compared with prevailing RNA-seq methods.
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33
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Mușat MG, Nițulescu GM, Surleac M, Tsatsakis A, Spandidos DA, Margină D. HIV‑1 integrase inhibitors targeting various DDE transposases: Retroviral integration versus RAG‑mediated recombination (Review). Mol Med Rep 2019; 20:4749-4762. [PMID: 31702817 PMCID: PMC6854553 DOI: 10.3892/mmr.2019.10777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 10/25/2019] [Indexed: 12/18/2022] Open
Abstract
Transposases are ubiquitous mobile genetic elements responsible for genome development, driving rearrangements, such as insertions, deletions and translocations. Across species evolution, some transposases are tamed by their host and are made part of complex cellular systems. The proliferation of retroviruses is also dependent on transposase related enzymes termed integrases. Recombination‑activating gene protein (RAG)1 and metnase are just two examples of transposase domestication and together with retroviral integrases (INs), they belong to the DDE polynucleotidyl transferases superfamily. They share mechanistic and structural features linked to the RNase H‑like fold, harboring a DDE(D) metal dependent catalytic motif. Recent antiretroviral compounds target the catalytic domain of integrase, but they also have the potential of inhibiting other related enzymes. In this review, we report the activity of different classes of integrase inhibitors on various DDE transposases. Computational simulations are useful to predict the extent of off‑target activity and have been employed to study the interactions between RAG1 recombinase and compounds from three different pharmacologic classes. We demonstrate that strand‑transfer inhibitors display a higher affinity towards the RAG1 RNase H domain, as suggested by experimental data compared to allosteric inhibitors. While interference with RAG1 and 2 recombination is associated with a negative impact on immune function, the inhibition of metnase or HTLV‑1 integrase opens the way for the development of novel therapies for refractory cancers.
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Affiliation(s)
- Mihaela Georgiana Mușat
- Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 020956 Bucharest, Romania
| | - George Mihai Nițulescu
- Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 020956 Bucharest, Romania
| | - Marius Surleac
- National Institute for Infectious Diseases ‘Matei Bals’, 021105 Bucharest, Romania
| | - Aristidis Tsatsakis
- Department of Forensic Sciences and Toxicology, School of Medicine, University of Crete, 71003 Heraklion, Greece
| | - Demetrios A. Spandidos
- Laboratory of Clinical Virology, School of Medicine, University of Crete, 71003 Heraklion, Greece
| | - Denisa Margină
- Faculty of Pharmacy, Carol Davila University of Medicine and Pharmacy, 020956 Bucharest, Romania
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34
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Arinkin V, Smyshlyaev G, Barabas O. Jump ahead with a twist: DNA acrobatics drive transposition forward. Curr Opin Struct Biol 2019; 59:168-177. [PMID: 31590109 PMCID: PMC6900584 DOI: 10.1016/j.sbi.2019.08.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 08/27/2019] [Accepted: 08/29/2019] [Indexed: 11/29/2022]
Abstract
Transposases move discrete pieces of DNA between genomic locations and had a profound impact on evolution. They drove the emergence of important biological functions and are the most frequent proteins encoded in modern genomes. Yet, the molecular principles of their actions have remained largely unclear. Here we review recent structural studies of transposase-DNA complexes and related cellular machineries, which provided unmatched mechanistic insights. We highlight how transposases introduce major DNA twists and kinks at various stages of their reaction and discuss the functional impact of these astounding DNA acrobatics on several aspects of transposition. By comparison with distantly related DNA recombination systems, we propose that forcing DNA into unnatural shapes may be a general strategy to drive rearrangements forward.
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Affiliation(s)
- Vladimir Arinkin
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Georgy Smyshlyaev
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany; European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, UK
| | - Orsolya Barabas
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany.
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35
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36
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Liu C, Yang Y, Schatz DG. Structures of a RAG-like transposase during cut-and-paste transposition. Nature 2019; 575:540-544. [PMID: 31723264 PMCID: PMC6872938 DOI: 10.1038/s41586-019-1753-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 09/30/2019] [Indexed: 12/27/2022]
Abstract
Transposons have had a pivotal role in genome evolution1 and are believed to be the evolutionary progenitors of the RAG1-RAG2 recombinase2, an essential component of the adaptive immune system in jawed vertebrates3. Here we report one crystal structure and five cryo-electron microscopy structures of Transib4,5, a RAG1-like transposase from Helicoverpa zea, that capture the entire transposition process from the apo enzyme to the terminal strand transfer complex with transposon ends covalently joined to target DNA, at resolutions of 3.0-4.6 Å. These structures reveal a butterfly-shaped complex that undergoes two cycles of marked conformational changes in which the 'wings' of the transposase unfurl to bind substrate DNA, close to execute cleavage, open to release the flanking DNA and close again to capture and attack target DNA. Transib possesses unique structural elements that compensate for the absence of a RAG2 partner, including a loop that interacts with the transposition target site and an accordion-like C-terminal tail that elongates and contracts to help to control the opening and closing of the enzyme and assembly of the active site. Our findings reveal the detailed reaction pathway of a eukaryotic cut-and-paste transposase and illuminate some of the earliest steps in the evolution of the RAG recombinase.
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Affiliation(s)
- Chang Liu
- Department of Immunobiology, Yale School of Medicine, New Haven, CT, USA
| | - Yang Yang
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, USA
- Howard Hughes Medical Institute, Yale University, New Haven, CT, USA
| | - David G Schatz
- Department of Immunobiology, Yale School of Medicine, New Haven, CT, USA.
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37
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Hickman AB, Voth AR, Ewis H, Li X, Craig NL, Dyda F. Structural insights into the mechanism of double strand break formation by Hermes, a hAT family eukaryotic DNA transposase. Nucleic Acids Res 2019; 46:10286-10301. [PMID: 30239795 PMCID: PMC6212770 DOI: 10.1093/nar/gky838] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 09/07/2018] [Indexed: 12/12/2022] Open
Abstract
Some DNA transposons relocate from one genomic location to another using a mechanism that involves generating double-strand breaks at their transposon ends by forming hairpins on flanking DNA. The same double-strand break mode is employed by the V(D)J recombinase at signal-end/coding-end junctions during the generation of antibody diversity. How flanking hairpins are formed during DNA transposition has remained elusive. Here, we describe several co-crystal structures of the Hermes transposase bound to DNA that mimics the reaction step immediately prior to hairpin formation. Our results reveal a large DNA conformational change between the initial cleavage step and subsequent hairpin formation that changes which strand is acted upon by a single active site. We observed that two factors affect the conformational change: the complement of divalent metal ions bound by the catalytically essential DDE residues, and the identity of the –2 flanking base pair. Our data also provides a mechanistic link between the efficiency of hairpin formation (an A:T basepair is favored at the –2 position) and Hermes' strong target site preference. Furthermore, we have established that the histidine residue within a conserved C/DxxH motif present in many transposase families interacts directly with the scissile phosphate, suggesting a crucial role in catalysis.
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Affiliation(s)
- Alison B Hickman
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Andrea Regier Voth
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hosam Ewis
- Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Xianghong Li
- Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Nancy L Craig
- Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Fred Dyda
- 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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Blundell-Hunter G, Tellier M, Chalmers R. Transposase subunit architecture and its relationship to genome size and the rate of transposition in prokaryotes and eukaryotes. Nucleic Acids Res 2019; 46:9637-9646. [PMID: 30184164 PMCID: PMC6182136 DOI: 10.1093/nar/gky794] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 09/01/2018] [Indexed: 12/17/2022] Open
Abstract
Cut-and-paste transposons are important tools for mutagenesis, gene-delivery and DNA sequencing applications. At the molecular level, the most thoroughly understood are Tn5 and Tn10 in bacteria, and mariner and hAT elements in eukaryotes. All bacterial cut-and-paste transposases characterized to date are monomeric prior to interacting with the transposon end, while all eukaryotic transposases are multimers. Although there is a limited sample size, we proposed that this defines two pathways for transpososome assembly which distinguishes the mechanism of the bacterial and eukaryotic transposons. We predicted that the respective pathways would dictate how the rate of transposition is related to transposase concentration and genome size. Here, we have tested these predictions by creating a single-chain dimer version of the bacterial Tn5 transposase. We show that artificial dimerization switches the transpososome assembly pathway from the bacterial-style to the eukaryotic-style. Although this had no effect in vitro, where the transposase does not have to search far to locate the transposon ends, it increased the rate of transposition in bacterial and HeLa cell assays. However, in contrast to the mariner elements, the Tn5 single-chain dimer remained unaffected by over-production inhibition, which is an emergent property of the transposase subunit structure in the mariner elements.
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Affiliation(s)
- George Blundell-Hunter
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - Michael Tellier
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - Ronald Chalmers
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK
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Abstract
In every cell from bacteria to mammals, NusG-like proteins bind transcribing RNA polymerase to modulate the rate of nascent RNA synthesis and to coordinate it with numerous cotranscriptional processes that ultimately determine the transcript fate. Housekeeping NusG factors regulate expression of the bulk of the genome, whereas their highly specialized paralogs control just a few targets. In every cell from bacteria to mammals, NusG-like proteins bind transcribing RNA polymerase to modulate the rate of nascent RNA synthesis and to coordinate it with numerous cotranscriptional processes that ultimately determine the transcript fate. Housekeeping NusG factors regulate expression of the bulk of the genome, whereas their highly specialized paralogs control just a few targets. In Escherichia coli, NusG stimulates silencing of horizontally acquired genes, while its paralog RfaH counters NusG action by activating a subset of these genes. Acting alone or as part of regulatory complexes, NusG factors can promote uninterrupted RNA synthesis, bring about transcription pausing or premature termination, modulate RNA processing, and facilitate translation. Recent structural and mechanistic studies of NusG homologs from all domains of life reveal molecular details of multifaceted interactions that underpin their unexpectedly diverse regulatory roles. NusG proteins share conserved binding sites on RNA polymerase and many effects on the transcription elongation complex but differ in their mechanisms of recruitment, interactions with nucleic acids and secondary partners, and regulatory outcomes. Strikingly, some can alternate between autoinhibited and activated states that possess dramatically different secondary structures to achieve exquisite target specificity.
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40
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Berg MD, Genereaux J, Zhu Y, Mian S, Gloor GB, Brandl CJ. Acceptor Stem Differences Contribute to Species-Specific Use of Yeast and Human tRNA Ser. Genes (Basel) 2018; 9:E612. [PMID: 30544642 PMCID: PMC6316282 DOI: 10.3390/genes9120612] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 11/22/2018] [Accepted: 12/03/2018] [Indexed: 01/01/2023] Open
Abstract
The molecular mechanisms of translation are highly conserved in all organisms indicative of a single evolutionary origin. This includes the molecular interactions of tRNAs with their cognate aminoacyl-tRNA synthetase, which must be precise to ensure the specificity of the process. For many tRNAs, the anticodon is a major component of the specificity. This is not the case for the aminoacylation of alanine and serine to their cognate tRNAs. Rather, aminoacylation relies on other features of the tRNA. For tRNASer, a key specificity feature is the variable arm, which is positioned between the anticodon arm and the T-arm. The variable arm is conserved from yeast to human. This work was initiated to determine if the structure/function of tRNASer has been conserved from Saccharomyces cerevisiae to human. We did this by detecting mistranslation in yeast cells with tRNASer derivatives having the UGA anticodon converted to UGG for proline. Despite being nearly identical in everything except the acceptor stem, human tRNASer is less active than yeast tRNASer. A chimeric tRNA with the human acceptor stem and other sequences from the yeast molecule acts similarly to the human tRNASer. The 3:70 base pair in the acceptor stem (C:G in yeast and A:U in humans) is a prime determinant of the specificity. Consistent with the functional difference of yeast and human tRNASer resulting from subtle changes in the specificity of their respective SerRS enzymes, the functionality of the human and chimeric tRNASerUGG molecules was enhanced when human SerRS was introduced into yeast. Residues in motif 2 of the aminoacylation domain of SerRS likely participated in the species-specific differences. Trp290 in yeast SerRS (Arg313 in humans) found in motif 2 is proximal to base 70 in models of the tRNA-synthetase interaction. Altering this motif 2 sequence of hSerRS to the yeast sequence decreases the activity of the human enzyme with human tRNASer, supporting the coadaptation of motif 2 loop⁻acceptor stem interactions.
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Affiliation(s)
- Matthew D Berg
- Department of Biochemistry, The University of Western Ontario, London, ON N6A 5C1, Canada.
| | - Julie Genereaux
- Department of Biochemistry, The University of Western Ontario, London, ON N6A 5C1, Canada.
| | - Yanrui Zhu
- Department of Biochemistry, The University of Western Ontario, London, ON N6A 5C1, Canada.
| | - Safee Mian
- Department of Biochemistry, The University of Western Ontario, London, ON N6A 5C1, Canada.
| | - Gregory B Gloor
- Department of Biochemistry, The University of Western Ontario, London, ON N6A 5C1, Canada.
| | - Christopher J Brandl
- Department of Biochemistry, The University of Western Ontario, London, ON N6A 5C1, Canada.
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41
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Structural gymnastics of RAG-mediated DNA cleavage in V(D)J recombination. Curr Opin Struct Biol 2018; 53:178-186. [PMID: 30476719 DOI: 10.1016/j.sbi.2018.11.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 11/05/2018] [Indexed: 11/22/2022]
Abstract
A hallmark of vertebrate immunity is the diverse repertoire of antigen-receptor genes that results from combinatorial splicing of gene coding segments by V(D)J recombination. The (RAG1-RAG2)2 endonuclease complex (RAG) specifically recognizes and cleaves a pair of recombination signal sequences (RSSs), 12-RSS and 23-RSS, via the catalytic steps of nicking and hairpin formation. Both RSSs immediately flank the coding end segments and are composed of a conserved heptamer, a conserved nonamer, and a non-conserved spacer of either 12 base pairs (bp) or 23 bp in between. A single RAG complex only synapses a 12-RSS and a 23-RSS, which was denoted the 12/23 rule, a dogma that ensures recombination between V, D and J segments, but not within the same type of segments. This review recapitulates current structural studies to highlight the conformational transformations in both the RAG complex and the RSS during the consecutive steps of catalysis. The emerging structural mechanism emphasizes distortion of intact RSS and nicked RSS exerted by a piston-like motion in RAG1 and by dimer closure, respectively. Bipartite recognition of heptamer and nonamer, flexibly linked nonamer-binding domain dimer relatively to the heptamer recognition region dimer, and RSS plasticity and bending by HMGB1 together contribute to the molecular basis of the 12/23 rule in the RAG molecular machine.
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42
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Chen W, Mandali S, Hancock SP, Kumar P, Collazo M, Cascio D, Johnson RC. Multiple serine transposase dimers assemble the transposon-end synaptic complex during IS 607-family transposition. eLife 2018; 7:e39611. [PMID: 30289389 PMCID: PMC6188088 DOI: 10.7554/elife.39611] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 09/18/2018] [Indexed: 11/13/2022] Open
Abstract
IS607-family transposons are unusual because they do not have terminal inverted repeats or generate target site duplications. They encode two protein-coding genes, but only tnpA is required for transposition. Our X-ray structures confirm that TnpA is a member of the serine recombinase (SR) family, but the chemically-inactive quaternary structure of the dimer, along with the N-terminal location of the DNA binding domain, are different from other SRs. TnpA dimers from IS1535 cooperatively associate with multiple subterminal repeats, which together with additional nonspecific binding, form a nucleoprotein filament on one transposon end that efficiently captures a second unbound end to generate the paired-end complex (PEC). Formation of the PEC does not require a change in the dimeric structure of the catalytic domain, but remodeling of the C-terminal α-helical region is involved. We posit that the PEC recruits a chemically-active conformer of TnpA to the transposon end to initiate DNA chemistry.
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Affiliation(s)
- Wenyang Chen
- Department of Biological ChemistryDavid Geffen School of Medicine, University of California at Los AngelesLos AngelesUnited States
| | - Sridhar Mandali
- Department of Biological ChemistryDavid Geffen School of Medicine, University of California at Los AngelesLos AngelesUnited States
| | - Stephen P Hancock
- Department of Biological ChemistryDavid Geffen School of Medicine, University of California at Los AngelesLos AngelesUnited States
| | - Pramod Kumar
- Department of Biological ChemistryDavid Geffen School of Medicine, University of California at Los AngelesLos AngelesUnited States
| | - Michael Collazo
- Department of Energy Institute of Genomics and ProteomicsUniversity of California at Los AngelesLos AngelesUnited States
| | - Duilio Cascio
- Department of Energy Institute of Genomics and ProteomicsUniversity of California at Los AngelesLos AngelesUnited States
| | - Reid C Johnson
- Department of Biological ChemistryDavid Geffen School of Medicine, University of California at Los AngelesLos AngelesUnited States
- Molecular Biology InstituteUniversity of California at Los AngelesLos AngelesUnited States
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43
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Abstract
The mechanism for initiating DNA cleavage by DDE-family enzymes, including the RAG endonuclease, which initiates V(D)J recombination, is not well understood. Here we report six cryo-EM structures of zebrafish RAG in complex with one or two intact recombination signal sequences (RSSs), at up to 3.9-Å resolution. Unexpectedly, these structures reveal DNA melting at the heptamer of the RSSs, thus resulting in a corkscrew-like rotation of coding-flank DNA and the positioning of the scissile phosphate in the active site. Substrate binding is associated with dimer opening and a piston-like movement in RAG1, first outward to accommodate unmelted DNA and then inward to wedge melted DNA. These precleavage complexes show limited base-specific contacts of RAG at the conserved terminal CAC/GTG sequence of the heptamer, thus suggesting conservation based on a propensity to unwind. CA and TG overwhelmingly dominate terminal sequences in transposons and retrotransposons, thereby implicating a universal mechanism for DNA melting during the initiation of retroviral integration and DNA transposition.
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44
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Sharma R, Nirwal S, Narayanan N, Nair DT. Dimerization through the RING-Finger Domain Attenuates Excision Activity of the piggyBac Transposase. Biochemistry 2018; 57:2913-2922. [DOI: 10.1021/acs.biochem.7b01191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Rahul Sharma
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121001, Haryana, India
- Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Shivlee Nirwal
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121001, Haryana, India
- Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Naveen Narayanan
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121001, Haryana, India
- Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Deepak T. Nair
- Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad 121001, Haryana, India
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45
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Zuber PK, Artsimovitch I, NandyMazumdar M, Liu Z, Nedialkov Y, Schweimer K, Rösch P, Knauer SH. The universally-conserved transcription factor RfaH is recruited to a hairpin structure of the non-template DNA strand. eLife 2018; 7:36349. [PMID: 29741479 PMCID: PMC5995543 DOI: 10.7554/elife.36349] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 05/05/2018] [Indexed: 12/31/2022] Open
Abstract
RfaH, a transcription regulator of the universally conserved NusG/Spt5 family, utilizes a unique mode of recruitment to elongating RNA polymerase to activate virulence genes. RfaH function depends critically on an ops sequence, an exemplar of a consensus pause, in the non-template DNA strand of the transcription bubble. We used structural and functional analyses to elucidate the role of ops in RfaH recruitment. Our results demonstrate that ops induces pausing to facilitate RfaH binding and establishes direct contacts with RfaH. Strikingly, the non-template DNA forms a hairpin in the RfaH:ops complex structure, flipping out a conserved T residue that is specifically recognized by RfaH. Molecular modeling and genetic evidence support the notion that ops hairpin is required for RfaH recruitment. We argue that both the sequence and the structure of the non-template strand are read out by transcription factors, expanding the repertoire of transcriptional regulators in all domains of life.
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Affiliation(s)
- Philipp K Zuber
- Lehrstuhl Biopolymere und Forschungszentrum für Bio-Makromoleküle, Universität Bayreuth, Bayreuth, Germany
| | - Irina Artsimovitch
- Department of Microbiology, The Ohio State University, Columbus, United States.,The Center for RNA Biology, The Ohio State University, Columbus, United States
| | - Monali NandyMazumdar
- Department of Microbiology, The Ohio State University, Columbus, United States.,The Center for RNA Biology, The Ohio State University, Columbus, United States
| | - Zhaokun Liu
- Department of Microbiology, The Ohio State University, Columbus, United States.,The Center for RNA Biology, The Ohio State University, Columbus, United States
| | - Yuri Nedialkov
- Department of Microbiology, The Ohio State University, Columbus, United States.,The Center for RNA Biology, The Ohio State University, Columbus, United States
| | - Kristian Schweimer
- Lehrstuhl Biopolymere und Forschungszentrum für Bio-Makromoleküle, Universität Bayreuth, Bayreuth, Germany
| | - Paul Rösch
- Lehrstuhl Biopolymere und Forschungszentrum für Bio-Makromoleküle, Universität Bayreuth, Bayreuth, Germany
| | - Stefan H Knauer
- Lehrstuhl Biopolymere und Forschungszentrum für Bio-Makromoleküle, Universität Bayreuth, Bayreuth, Germany
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46
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Morellet N, Li X, Wieninger SA, Taylor JL, Bischerour J, Moriau S, Lescop E, Bardiaux B, Mathy N, Assrir N, Bétermier M, Nilges M, Hickman AB, Dyda F, Craig NL, Guittet E. Sequence-specific DNA binding activity of the cross-brace zinc finger motif of the piggyBac transposase. Nucleic Acids Res 2018; 46:2660-2677. [PMID: 29385532 PMCID: PMC5861402 DOI: 10.1093/nar/gky044] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 01/12/2018] [Accepted: 01/17/2018] [Indexed: 12/16/2022] Open
Abstract
The piggyBac transposase (PB) is distinguished by its activity and utility in genome engineering, especially in humans where it has highly promising therapeutic potential. Little is known, however, about the structure-function relationships of the different domains of PB. Here, we demonstrate in vitro and in vivo that its C-terminal Cysteine-Rich Domain (CRD) is essential for DNA breakage, joining and transposition and that it binds to specific DNA sequences in the left and right transposon ends, and to an additional unexpectedly internal site at the left end. Using NMR, we show that the CRD adopts the specific fold of the cross-brace zinc finger protein family. We determine the interaction interfaces between the CRD and its target, the 5'-TGCGT-3'/3'-ACGCA-5' motifs found in the left, left internal and right transposon ends, and use NMR results to propose docking models for the complex, which are consistent with our site-directed mutagenesis data. Our results provide support for a model of the PB/DNA interactions in the context of the transpososome, which will be useful for the rational design of PB mutants with increased activity.
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Affiliation(s)
- Nelly Morellet
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Saclay, 91198 Gif sur Yvette cedex, France
| | - Xianghong Li
- Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Silke A Wieninger
- Institut Pasteur, Unité de Bioinformatique Structurale, CNRS UMR 3528, Département de Biologie Structurale et Chimie, Paris, France
| | - Jennifer L Taylor
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Julien Bischerour
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette cedex, France
| | - Séverine Moriau
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Saclay, 91198 Gif sur Yvette cedex, France
| | - Ewen Lescop
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Saclay, 91198 Gif sur Yvette cedex, France
| | - Benjamin Bardiaux
- Institut Pasteur, Unité de Bioinformatique Structurale, CNRS UMR 3528, Département de Biologie Structurale et Chimie, Paris, France
| | - Nathalie Mathy
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette cedex, France
| | - Nadine Assrir
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Saclay, 91198 Gif sur Yvette cedex, France
| | - Mireille Bétermier
- Institute of Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198 Gif sur Yvette cedex, France
| | - Michael Nilges
- Institut Pasteur, Unité de Bioinformatique Structurale, CNRS UMR 3528, Département de Biologie Structurale et Chimie, Paris, France
| | - Alison B Hickman
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Fred Dyda
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Nancy L Craig
- Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Eric Guittet
- Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Saclay, 91198 Gif sur Yvette cedex, France
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47
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Large-Scale Low-Cost NGS Library Preparation Using a Robust Tn5 Purification and Tagmentation Protocol. G3-GENES GENOMES GENETICS 2018; 8:79-89. [PMID: 29118030 PMCID: PMC5765368 DOI: 10.1534/g3.117.300257] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Efficient preparation of high-quality sequencing libraries that well represent the biological sample is a key step for using next-generation sequencing in research. Tn5 enables fast, robust, and highly efficient processing of limited input material while scaling to the parallel processing of hundreds of samples. Here, we present a robust Tn5 transposase purification strategy based on an N-terminal His6-Sumo3 tag. We demonstrate that libraries prepared with our in-house Tn5 are of the same quality as those processed with a commercially available kit (Nextera XT), while they dramatically reduce the cost of large-scale experiments. We introduce improved purification strategies for two versions of the Tn5 enzyme. The first version carries the previously reported point mutations E54K and L372P, and stably produces libraries of constant fragment size distribution, even if the Tn5-to-input molecule ratio varies. The second Tn5 construct carries an additional point mutation (R27S) in the DNA-binding domain. This construct allows for adjustment of the fragment size distribution based on enzyme concentration during tagmentation, a feature that opens new opportunities for use of Tn5 in customized experimental designs. We demonstrate the versatility of our Tn5 enzymes in different experimental settings, including a novel single-cell polyadenylation site mapping protocol as well as ultralow input DNA sequencing.
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48
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Abstract
Integration of the reverse-transcribed viral cDNA into the host's genome is a critical step in the lifecycle of all retroviruses. Retrovirus integration is carried out by integrase (IN), a virus-encoded enzyme that forms an oligomeric 'intasome' complex with both ends of the linear viral DNA to catalyze their concerted insertions into the backbones of the host's DNA. IN also forms a complex with host proteins, which guides the intasome to the host's chromosome. Recent structural studies have revealed remarkable diversity as well as conserved features among the architectures of the intasome assembly from different genera of retroviruses. This chapter will review how IN oligomerizes to achieve its function, with particular focus on alpharetrovirus including the avian retrovirus Rous sarcoma virus. Another chapter (Craigie) will focus on the structure and function of IN from HIV-1.
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Affiliation(s)
- Duane P Grandgenett
- Saint Louis University Health Sciences Center, Department of Microbiology and Immunology, Institute for Molecular Virology, Doisy Research Center, St. Louis, MO, USA
| | - Hideki Aihara
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.
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49
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Claeys Bouuaert C, Chalmers R. A single active site in the mariner transposase cleaves DNA strands of opposite polarity. Nucleic Acids Res 2017; 45:11467-11478. [PMID: 29036477 PMCID: PMC5714172 DOI: 10.1093/nar/gkx826] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Accepted: 09/08/2017] [Indexed: 01/01/2023] Open
Abstract
The RNase H structural fold defines a large family of nucleic acid metabolizing enzymes that catalyze phosphoryl transfer reactions using two divalent metal ions in the active site. Almost all of these reactions involve only one strand of the nucleic acid substrates. In contrast, cut-and-paste transposases cleave two DNA strands of opposite polarity, which is usually achieved via an elegant hairpin mechanism. In the mariner transposons, the hairpin intermediate is absent and key aspects of the mechanism by which the transposon ends are cleaved remained unknown. Here, we characterize complexes involved prior to catalysis, which define an asymmetric pathway for transpososome assembly. Using mixtures of wild-type and catalytically inactive transposases, we show that all the catalytic steps of transposition occur within the context of a dimeric transpososome. Crucially, we find that each active site of a transposase dimer is responsible for two hydrolysis and one transesterification reaction at the same transposon end. These results provide the first strong evidence that a DDE/D active site can hydrolyze DNA strands of opposite polarity, a mechanism that has rarely been observed with any type of nuclease.
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Affiliation(s)
- Corentin Claeys Bouuaert
- School of Biomedical Sciences, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - Ronald Chalmers
- School of Biomedical Sciences, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK
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50
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Engelman AN, Cherepanov P. Retroviral intasomes arising. Curr Opin Struct Biol 2017; 47:23-29. [PMID: 28458055 PMCID: PMC5660667 DOI: 10.1016/j.sbi.2017.04.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 04/10/2017] [Accepted: 04/11/2017] [Indexed: 01/26/2023]
Abstract
Retroviral DNA integration takes place in the context of the intasome nucleoprotein complex. X-ray crystal structures of functional spumaviral intasomes were previously revealed to harbor a homotetramer of integrase, and it was generally believed that integrase tetramers catalyzed the integration of other retroviruses. The elucidation of new structures from four different retroviruses over the past year has however revealed this is not the case. The number of integrase molecules required to construct the conserved intasome core structure differs between viral species. While four subunits suffice for spumaviruses, α- and β-retroviruses require eight and the lentiviruses use up to sixteen. Herein we described these alternative architectures, highlighting both evolutionary and structural constraints that result in the different integrase-DNA stoichiometries across Retroviridae.
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Affiliation(s)
- Alan N Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Medicine, Harvard Medical School, Boston, MA 02115, USA.
| | - Peter Cherepanov
- Chromatin Structure and Mobile DNA, The Francis Crick Institute, London NW1 1AT, UK; Department of Medicine, Imperial College London, St-Mary's Campus, Norfolk Place, London W2 1PG, UK.
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