1
|
Lampe GD, Liang AR, Zhang DJ, Fernández IS, Sternberg SH. Structure-guided engineering of type I-F CASTs for targeted gene insertion in human cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.19.613948. [PMID: 39345383 PMCID: PMC11429998 DOI: 10.1101/2024.09.19.613948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 10/01/2024]
Abstract
Conventional genome editing tools rely on DNA double-strand breaks (DSBs) and host recombination proteins to achieve large insertions, resulting in a heterogeneous mixture of undesirable editing outcomes. We recently leveraged a type I-F CRISPR-associated transposase (CAST) from the Pseudoalteromonas Tn 7016 transposon ( Pse CAST) for DSB-free, RNA-guided DNA integration in human cells, taking advantage of its programmability and large payload capacity. Pse CAST is the only characterized CAST system that has achieved human genomic DNA insertions, but multiple lines of evidence suggest that DNA binding may be a critical bottleneck that limits high-efficiency activity. Here we report structural determinants of target DNA recognition by the Pse CAST QCascade complex using single-particle cryogenic electron microscopy (cryoEM), which revealed novel subtype-specific interactions and RNA-DNA heteroduplex features. By combining our structural data with target DNA library screens and rationally engineered protein mutations, we uncovered CAST variants that exhibit increased integration efficiency and modified PAM stringency. Structure predictions of key interfaces in the transpososome holoenzyme also revealed opportunities for the design of hybrid CASTs, which we leveraged to build chimeric systems that combine high-activity DNA binding and DNA integration modules. Collectively, our work provides unique structural insights into type I-F CAST systems while showcasing multiple diverse strategies to investigate and engineer new RNA-guided transposase architectures for human genome editing applications.
Collapse
|
2
|
Hsieh SC, Peters JE. Natural and Engineered Guide RNA-Directed Transposition with CRISPR-Associated Tn7-Like Transposons. Annu Rev Biochem 2024; 93:139-161. [PMID: 38598855 PMCID: PMC11406308 DOI: 10.1146/annurev-biochem-030122-041908] [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] [Indexed: 04/12/2024]
Abstract
CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR-associated nuclease) defense systems have been naturally coopted for guide RNA-directed transposition on multiple occasions. In all cases, cooption occurred with diverse elements related to the bacterial transposon Tn7. Tn7 tightly controls transposition; the transposase is activated only when special targets are recognized by dedicated target-site selection proteins. Tn7 and the Tn7-like elements that coopted CRISPR-Cas systems evolved complementary targeting pathways: one that recognizes a highly conserved site in the chromosome and a second pathway that targets mobile plasmids capable of cell-to-cell transfer. Tn7 and Tn7-like elements deliver a single integration into the site they recognize and also control the orientation of the integration event, providing future potential for use as programmable gene-integration tools. Early work has shown that guide RNA-directed transposition systems can be adapted to diverse hosts, even within microbial communities, suggesting great potential for engineering these systems as powerful gene-editing tools.
Collapse
Affiliation(s)
- Shan-Chi Hsieh
- Department of Microbiology, Cornell University, Ithaca, New York, USA;
| | - Joseph E Peters
- Department of Microbiology, Cornell University, Ithaca, New York, USA;
| |
Collapse
|
3
|
Chang CW, Truong VA, Pham NN, Hu YC. RNA-guided genome engineering: paradigm shift towards transposons. Trends Biotechnol 2024; 42:970-985. [PMID: 38443218 DOI: 10.1016/j.tibtech.2024.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 02/05/2024] [Accepted: 02/06/2024] [Indexed: 03/07/2024]
Abstract
CRISPR-Cas systems revolutionized the genome engineering field but need to induce double-strand breaks (DSBs) and may be difficult to deliver due to their large protein size. Tn7-like transposons such as CRISPR-associated transposons (CASTs) can be repurposed for RNA-guided DSB-free integration, and obligate mobile element guided activity (OMEGA) proteins of the IS200/IS605 transposon family have been developed as hypercompact RNA-guided genome editing tools. CASTs and OMEGA are exciting, innovative genome engineering tools that can improve the precision and efficiency of editing. This review explores the recent developments and uses of CASTs and OMEGA in genome editing across prokaryotic and eukaryotic cells. The pros and cons of these transposon-based systems are deliberated in comparison to other CRISPR systems.
Collapse
Affiliation(s)
- Chin-Wei Chang
- Department of Chemical Engineering, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Vy Anh Truong
- Department of Chemical Engineering, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Nam Ngoc Pham
- Department of Chemical Engineering, National Tsing Hua University, Hsinchu 300, Taiwan
| | - Yu-Chen Hu
- Department of Chemical Engineering, National Tsing Hua University, Hsinchu 300, Taiwan; Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 300, Taiwan.
| |
Collapse
|
4
|
Zhao X, Gao Y, Gong Q, Zhang K, Li S. Elucidating the Architectural dynamics of MuB filaments in bacteriophage Mu DNA transposition. Nat Commun 2024; 15:6445. [PMID: 39085263 PMCID: PMC11292022 DOI: 10.1038/s41467-024-50722-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 07/18/2024] [Indexed: 08/02/2024] Open
Abstract
MuB is a non-specific DNA-binding protein and AAA+ ATPase that significantly influences the DNA transposition process of bacteriophage Mu, especially in target DNA selection for transposition. While studies have established the ATP-dependent formation of MuB filament as pivotal to this process, the high-resolution structure of a full-length MuB protomer and the underlying molecular mechanisms governing its oligomerization remain elusive. Here, we use cryo-EM to obtain a 3.4-Å resolution structure of the ATP(+)-DNA(+)-MuB helical filament, which encapsulates the DNA substrate within its axial channel. The structure categorizes MuB within the initiator clade of the AAA+ protein family and precisely locates the ATP and DNA binding sites. Further investigation into the oligomeric states of MuB show the existence of various forms of the filament. These findings lead to a mechanistic model where MuB forms opposite helical filaments along the DNA, exposing potential target sites on the bare DNA and then recruiting MuA, which stimulates MuB's ATPase activity and disrupts the previously formed helical structure. When this happens, MuB generates larger ring structures and dissociates from the DNA.
Collapse
Affiliation(s)
- Xiaolong Zhao
- Department of Urology, The First Affiliated Hospital of USTC, MOE Key Laboratory for Cellular Dynamics, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Yongxiang Gao
- Department of Urology, The First Affiliated Hospital of USTC, MOE Key Laboratory for Cellular Dynamics, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Qingguo Gong
- Department of Urology, The First Affiliated Hospital of USTC, MOE Key Laboratory for Cellular Dynamics, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Kaiming Zhang
- Department of Urology, The First Affiliated Hospital of USTC, MOE Key Laboratory for Cellular Dynamics, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.
| | - Shanshan Li
- Department of Urology, The First Affiliated Hospital of USTC, MOE Key Laboratory for Cellular Dynamics, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.
| |
Collapse
|
5
|
Shen Y, Krishnan SS, Petassi MT, Hancock MA, Peters JE, Guarné A. Assembly of the Tn7 targeting complex by a regulated stepwise process. Mol Cell 2024; 84:2368-2381.e6. [PMID: 38834067 PMCID: PMC11364213 DOI: 10.1016/j.molcel.2024.05.012] [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: 06/20/2023] [Revised: 01/08/2024] [Accepted: 05/12/2024] [Indexed: 06/06/2024]
Abstract
The Tn7 family of transposons is notable for its highly regulated integration mechanisms, including programmable RNA-guided transposition. The targeting pathways rely on dedicated target selection proteins from the TniQ family and the AAA+ adaptor TnsC to recruit and activate the transposase at specific target sites. Here, we report the cryoelectron microscopy (cryo-EM) structures of TnsC bound to the TniQ domain of TnsD from prototypical Tn7 and unveil key regulatory steps stemming from unique behaviors of ATP- versus ADP-bound TnsC. We show that TnsD recruits ADP-bound dimers of TnsC and acts as an exchange factor to release one protomer with exchange to ATP. This loading process explains how TnsC assembles a heptameric ring unidirectionally from the target site. This unique loading process results in functionally distinct TnsC protomers within the ring, providing a checkpoint for target immunity and explaining how insertions at programmed sites precisely occur in a specific orientation across Tn7 elements.
Collapse
Affiliation(s)
- Yao Shen
- Department of Biochemistry, McGill University, Montreal, QC H3G 0B1, Canada; Centre de recherche en biologie structurale (CRBS), McGill University, Montreal, QC H3G 0B1, Canada
| | - Shreya S Krishnan
- Department of Biochemistry, McGill University, Montreal, QC H3G 0B1, Canada; Centre de recherche en biologie structurale (CRBS), McGill University, Montreal, QC H3G 0B1, Canada
| | - Michael T Petassi
- Department of Microbiology, Cornell University, Ithaca, NY 14853, USA
| | - Mark A Hancock
- Centre de recherche en biologie structurale (CRBS), McGill University, Montreal, QC H3G 0B1, Canada; Department of Pharmacology and Therapeutics, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Joseph E Peters
- Department of Microbiology, Cornell University, Ithaca, NY 14853, USA
| | - Alba Guarné
- Department of Biochemistry, McGill University, Montreal, QC H3G 0B1, Canada; Centre de recherche en biologie structurale (CRBS), McGill University, Montreal, QC H3G 0B1, Canada.
| |
Collapse
|
6
|
Tenjo-Castaño F, Sofos N, Stutzke LS, Temperini P, Fuglsang A, Pape T, Mesa P, Montoya G. Conformational landscape of the type V-K CRISPR-associated transposon integration assembly. Mol Cell 2024; 84:2353-2367.e5. [PMID: 38834066 DOI: 10.1016/j.molcel.2024.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 03/11/2024] [Accepted: 05/07/2024] [Indexed: 06/06/2024]
Abstract
CRISPR-associated transposons (CASTs) are mobile genetic elements that co-opt CRISPR-Cas systems for RNA-guided DNA transposition. CASTs integrate large DNA cargos into the attachment (att) site independently of homology-directed repair and thus hold promise for eukaryotic genome engineering. However, the functional diversity and complexity of CASTs hinder an understanding of their mechanisms. Here, we present the high-resolution cryoelectron microscopy (cryo-EM) structure of the reconstituted ∼1 MDa post-transposition complex of the type V-K CAST, together with different assembly intermediates and diverse TnsC filament lengths, thus enabling the recapitulation of the integration complex formation. The results of mutagenesis experiments probing the roles of specific residues and TnsB-binding sites show that transposition activity can be enhanced and suggest that the distance between the PAM and att sites is determined by the lengths of the TnsB C terminus and the TnsC filament. This singular model of RNA-guided transposition provides a foundation for repurposing the system for genome-editing applications.
Collapse
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, Blegdamsvej 3B, 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, Blegdamsvej 3B, 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, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Piero Temperini
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 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, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Tillmann Pape
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark; Core Facility for Integrated Microscopy (CFIM), Faculty of Health and Medical Sciences University of Copenhagen; Blegdamsvej 3B, DK-2200 Copenhagen, Denmark
| | - Pablo Mesa
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 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, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
| |
Collapse
|
7
|
Villiger L, Joung J, Koblan L, Weissman J, Abudayyeh OO, Gootenberg JS. CRISPR technologies for genome, epigenome and transcriptome editing. Nat Rev Mol Cell Biol 2024; 25:464-487. [PMID: 38308006 DOI: 10.1038/s41580-023-00697-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/18/2023] [Indexed: 02/04/2024]
Abstract
Our ability to edit genomes lags behind our capacity to sequence them, but the growing understanding of CRISPR biology and its application to genome, epigenome and transcriptome engineering is narrowing this gap. In this Review, we discuss recent developments of various CRISPR-based systems that can transiently or permanently modify the genome and the transcriptome. The discovery of further CRISPR enzymes and systems through functional metagenomics has meaningfully broadened the applicability of CRISPR-based editing. Engineered Cas variants offer diverse capabilities such as base editing, prime editing, gene insertion and gene regulation, thereby providing a panoply of tools for the scientific community. We highlight the strengths and weaknesses of current CRISPR tools, considering their efficiency, precision, specificity, reliance on cellular DNA repair mechanisms and their applications in both fundamental biology and therapeutics. Finally, we discuss ongoing clinical trials that illustrate the potential impact of CRISPR systems on human health.
Collapse
Affiliation(s)
- Lukas Villiger
- McGovern Institute for Brain Research, Massachusetts Institute of Technology Cambridge, Cambridge, MA, USA
| | - Julia Joung
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Luke Koblan
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Jonathan Weissman
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Omar O Abudayyeh
- McGovern Institute for Brain Research, Massachusetts Institute of Technology Cambridge, Cambridge, MA, USA.
| | - Jonathan S Gootenberg
- McGovern Institute for Brain Research, Massachusetts Institute of Technology Cambridge, Cambridge, MA, USA.
| |
Collapse
|
8
|
Ganguly C, Rostami S, Long K, Aribam SD, Rajan R. Unity among the diverse RNA-guided CRISPR-Cas interference mechanisms. J Biol Chem 2024; 300:107295. [PMID: 38641067 PMCID: PMC11127173 DOI: 10.1016/j.jbc.2024.107295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 04/08/2024] [Accepted: 04/10/2024] [Indexed: 04/21/2024] Open
Abstract
CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR-associated) systems are adaptive immune systems that protect bacteria and archaea from invading mobile genetic elements (MGEs). The Cas protein-CRISPR RNA (crRNA) complex uses complementarity of the crRNA "guide" region to specifically recognize the invader genome. CRISPR effectors that perform targeted destruction of the foreign genome have emerged independently as multi-subunit protein complexes (Class 1 systems) and as single multi-domain proteins (Class 2). These different CRISPR-Cas systems can cleave RNA, DNA, and protein in an RNA-guided manner to eliminate the invader, and in some cases, they initiate programmed cell death/dormancy. The versatile mechanisms of the different CRISPR-Cas systems to target and destroy nucleic acids have been adapted to develop various programmable-RNA-guided tools and have revolutionized the development of fast, accurate, and accessible genomic applications. In this review, we present the structure and interference mechanisms of different CRISPR-Cas systems and an analysis of their unified features. The three types of Class 1 systems (I, III, and IV) have a conserved right-handed helical filamentous structure that provides a backbone for sequence-specific targeting while using unique proteins with distinct mechanisms to destroy the invader. Similarly, all three Class 2 types (II, V, and VI) have a bilobed architecture that binds the RNA-DNA/RNA hybrid and uses different nuclease domains to cleave invading MGEs. Additionally, we highlight the mechanistic similarities of CRISPR-Cas enzymes with other RNA-cleaving enzymes and briefly present the evolutionary routes of the different CRISPR-Cas systems.
Collapse
Affiliation(s)
- Chhandosee Ganguly
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma, USA
| | - Saadi Rostami
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma, USA
| | - Kole Long
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma, USA
| | - Swarmistha Devi Aribam
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma, USA
| | - Rakhi Rajan
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma, USA.
| |
Collapse
|
9
|
de la Gándara Á, Spínola-Amilibia M, Araújo-Bazán L, Núñez-Ramírez R, Berger JM, Arias-Palomo E. Molecular basis for transposase activation by a dedicated AAA+ ATPase. Nature 2024; 630:1003-1011. [PMID: 38926614 PMCID: PMC11208146 DOI: 10.1038/s41586-024-07550-6] [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: 08/11/2023] [Accepted: 05/09/2024] [Indexed: 06/28/2024]
Abstract
Transposases drive chromosomal rearrangements and the dissemination of drug-resistance genes and toxins1-3. Although some transposases act alone, many rely on dedicated AAA+ ATPase subunits that regulate site selectivity and catalytic function through poorly understood mechanisms. Using IS21 as a model transposase system, we show how an ATPase regulator uses nucleotide-controlled assembly and DNA deformation to enable structure-based site selectivity, transposase recruitment, and activation and integration. Solution and cryogenic electron microscopy studies show that the IstB ATPase self-assembles into an autoinhibited pentamer of dimers that tightly curves target DNA into a half-coil. Two of these decamers dimerize, which stabilizes the target nucleic acid into a kinked S-shaped configuration that engages the IstA transposase at the interface between the two IstB oligomers to form an approximately 1 MDa transpososome complex. Specific interactions stimulate regulator ATPase activity and trigger a large conformational change on the transposase that positions the catalytic site to perform DNA strand transfer. These studies help explain how AAA+ ATPase regulators-which are used by classical transposition systems such as Tn7, Mu and CRISPR-associated elements-can remodel their substrate DNA and cognate transposases to promote function.
Collapse
Affiliation(s)
| | | | - Lidia Araújo-Bazán
- Centro de Investigaciones Biológicas Margarita Salas, CSIC, Madrid, Spain
| | | | - James M Berger
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | | |
Collapse
|
10
|
Hwang J, Ye DY, Jung GY, Jang S. Mobile genetic element-based gene editing and genome engineering: Recent advances and applications. Biotechnol Adv 2024; 72:108343. [PMID: 38521283 DOI: 10.1016/j.biotechadv.2024.108343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 03/14/2024] [Accepted: 03/16/2024] [Indexed: 03/25/2024]
Abstract
Genome engineering has revolutionized several scientific fields, ranging from biochemistry and fundamental research to therapeutic uses and crop development. Diverse engineering toolkits have been developed and used to effectively modify the genome sequences of organisms. However, there is a lack of extensive reviews on genome engineering technologies based on mobile genetic elements (MGEs), which induce genetic diversity within host cells by changing their locations in the genome. This review provides a comprehensive update on the versatility of MGEs as powerful genome engineering tools that offers efficient solutions to challenges associated with genome engineering. MGEs, including DNA transposons, retrotransposons, retrons, and CRISPR-associated transposons, offer various advantages, such as a broad host range, genome-wide mutagenesis, efficient large-size DNA integration, multiplexing capabilities, and in situ single-stranded DNA generation. We focused on the components, mechanisms, and features of each MGE-based tool to highlight their cellular applications. Finally, we discussed the current challenges of MGE-based genome engineering and provided insights into the evolving landscape of this transformative technology. In conclusion, the combination of genome engineering with MGE demonstrates remarkable potential for addressing various challenges and advancing the field of genetic manipulation, and promises to revolutionize our ability to engineer and understand the genomes of diverse organisms.
Collapse
Affiliation(s)
- Jaeseong Hwang
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-gu, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Dae-Yeol Ye
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-gu, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Gyoo Yeol Jung
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-gu, Pohang, Gyeongbuk 37673, Republic of Korea; Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-gu, Pohang, Gyeongbuk 37673, Republic of Korea.
| | - Sungho Jang
- Department of Bioengineering and Nano-Bioengineering, Incheon National University, 119 Academy-ro, Yeonsu-gu, Incheon 22012, Republic of Korea; Division of Bioengineering, College of Life Sciences and Bioengineering, Incheon National University, 119 Academy-ro, Yeonsu-gu, Incheon 22012, Republic of Korea; Research Center for Bio Materials & Process Development, Incheon National University, 119 Academy-ro, Yeonsu-gu, Incheon 22012, Republic of Korea.
| |
Collapse
|
11
|
Arévalo S, Pérez Rico D, Abarca D, Dijkhuizen LW, Sarasa-Buisan C, Lindblad P, Flores E, Nierzwicki-Bauer S, Schluepmann H. Genome Engineering by RNA-Guided Transposition for Anabaena sp. PCC 7120. ACS Synth Biol 2024; 13:901-912. [PMID: 38445989 PMCID: PMC10949235 DOI: 10.1021/acssynbio.3c00583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 01/30/2024] [Accepted: 02/16/2024] [Indexed: 03/07/2024]
Abstract
In genome engineering, the integration of incoming DNA has been dependent on enzymes produced by dividing cells, which has been a bottleneck toward increasing DNA insertion frequencies and accuracy. Recently, RNA-guided transposition with CRISPR-associated transposase (CAST) was reported as highly effective and specific in Escherichia coli. Here, we developed Golden Gate vectors to test CAST in filamentous cyanobacteria and to show that it is effective in Anabaena sp. strain PCC 7120. The comparatively large plasmids containing CAST and the engineered transposon were successfully transferred into Anabaena via conjugation using either suicide or replicative plasmids. Single guide (sg) RNA encoding the leading but not the reverse complement strand of the target were effective with the protospacer-associated motif (PAM) sequence included in the sgRNA. In four out of six cases analyzed over two distinct target loci, the insertion site was exactly 63 bases after the PAM. CAST on a replicating plasmid was toxic, which could be used to cure the plasmid. In all six cases analyzed, only the transposon cargo defined by the sequence ranging from left and right elements was inserted at the target loci; therefore, RNA-guided transposition resulted from cut and paste. No endogenous transposons were remobilized by exposure to CAST enzymes. This work is foundational for genome editing by RNA-guided transposition in filamentous cyanobacteria, whether in culture or in complex communities.
Collapse
Affiliation(s)
- Sergio Arévalo
- Biology
Department, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- Microbial
Chemistry, Department of Chemistry-Ångström Laboratory, Uppsala University, Lägerhyddsvägen 1, 751
20 Uppsala, Sweden
- Instituto
de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad
de Sevilla, Avenida Americo Vespucio 49, Sevilla 41092, Spain
- Department
of Biological Sciences, Rensselaer Polytechnic
Institute, 110 Eighth
Street, Troy, New York 12180-3590, United
States
| | - Daniel Pérez Rico
- Biology
Department, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Dolores Abarca
- Biology
Department, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Laura W. Dijkhuizen
- Biology
Department, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Cristina Sarasa-Buisan
- Instituto
de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad
de Sevilla, Avenida Americo Vespucio 49, Sevilla 41092, Spain
| | - Peter Lindblad
- Microbial
Chemistry, Department of Chemistry-Ångström Laboratory, Uppsala University, Lägerhyddsvägen 1, 751
20 Uppsala, Sweden
| | - Enrique Flores
- Instituto
de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad
de Sevilla, Avenida Americo Vespucio 49, Sevilla 41092, Spain
| | - Sandra Nierzwicki-Bauer
- Department
of Biological Sciences, Rensselaer Polytechnic
Institute, 110 Eighth
Street, Troy, New York 12180-3590, United
States
| | - Henriette Schluepmann
- Biology
Department, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| |
Collapse
|
12
|
Chen X, Du J, Yun S, Xue C, Yao Y, Rao S. Recent advances in CRISPR-Cas9-based genome insertion technologies. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102138. [PMID: 38379727 PMCID: PMC10878794 DOI: 10.1016/j.omtn.2024.102138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Programmable genome insertion (or knock-in) is vital for both fundamental and translational research. The continuously expanding number of CRISPR-based genome insertion strategies demonstrates the ongoing development in this field. Common methods for site-specific genome insertion rely on cellular double-strand breaks repair pathways, such as homology-directed repair, non-homologous end-joining, and microhomology-mediated end joining. Recent advancements have further expanded the toolbox of programmable genome insertion techniques, including prime editing, integrase coupled with programmable nuclease, and CRISPR-associated transposon. These tools possess their own capabilities and limitations, promoting tremendous efforts to enhance editing efficiency, broaden targeting scope and improve editing specificity. In this review, we first summarize recent advances in programmable genome insertion techniques. We then elaborate on the cons and pros of each technique to assist researchers in making informed choices when using these tools. Finally, we identify opportunities for future improvements and applications in basic research and therapeutics.
Collapse
Affiliation(s)
- Xinwen Chen
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China
- Tianjin Institutes of Health Science, Tianjin 301600, China
| | - Jingjing Du
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China
- Tianjin Institutes of Health Science, Tianjin 301600, China
| | - Shaowei Yun
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China
- Tianjin Institutes of Health Science, Tianjin 301600, China
| | - Chaoyou Xue
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin 300308, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yao Yao
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China
- Tianjin Institutes of Health Science, Tianjin 301600, China
| | - Shuquan Rao
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China
- Tianjin Institutes of Health Science, Tianjin 301600, China
| |
Collapse
|
13
|
Chia SPS, Pang JKS, Soh BS. Current RNA strategies in treating cardiovascular diseases. Mol Ther 2024; 32:580-608. [PMID: 38291757 PMCID: PMC10928165 DOI: 10.1016/j.ymthe.2024.01.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 12/22/2023] [Accepted: 01/23/2024] [Indexed: 02/01/2024] Open
Abstract
Cardiovascular disease (CVD) continues to impose a significant global health burden, necessitating the exploration of innovative treatment strategies. Ribonucleic acid (RNA)-based therapeutics have emerged as a promising avenue to address the complex molecular mechanisms underlying CVD pathogenesis. We present a comprehensive review of the current state of RNA therapeutics in the context of CVD, focusing on the diverse modalities that bring about transient or permanent modifications by targeting the different stages of the molecular biology central dogma. Considering the immense potential of RNA therapeutics, we have identified common gene targets that could serve as potential interventions for prevalent Mendelian CVD caused by single gene mutations, as well as acquired CVDs developed over time due to various factors. These gene targets offer opportunities to develop RNA-based treatments tailored to specific genetic and molecular pathways, presenting a novel and precise approach to address the complex pathogenesis of both types of cardiovascular conditions. Additionally, we discuss the challenges and opportunities associated with delivery strategies to achieve targeted delivery of RNA therapeutics to the cardiovascular system. This review highlights the immense potential of RNA-based interventions as a novel and precise approach to combat CVD, paving the way for future advancements in cardiovascular therapeutics.
Collapse
Affiliation(s)
- Shirley Pei Shan Chia
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A∗STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore; Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore 117558, Singapore
| | - Jeremy Kah Sheng Pang
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A∗STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore
| | - Boon-Seng Soh
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A∗STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore; Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore 117558, Singapore.
| |
Collapse
|
14
|
Gelsinger DR, Vo PLH, Klompe SE, Ronda C, Wang HH, Sternberg SH. Bacterial genome engineering using CRISPR-associated transposases. Nat Protoc 2024; 19:752-790. [PMID: 38216671 DOI: 10.1038/s41596-023-00927-3] [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: 02/17/2023] [Accepted: 10/02/2023] [Indexed: 01/14/2024]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR)-associated transposases have the potential to transform the technology landscape for kilobase-scale genome engineering, by virtue of their ability to integrate large genetic payloads with high accuracy, easy programmability and no requirement for homologous recombination machinery. These transposons encode efficient, CRISPR RNA-guided transposases that execute genomic insertions in Escherichia coli at efficiencies approaching ~100%. Moreover, they generate multiplexed edits when programmed with multiple guides, and function robustly in diverse Gram-negative bacterial species. Here we present a detailed protocol for engineering bacterial genomes using CRISPR-associated transposase (CAST) systems, including guidelines on the available vectors, customization of guide RNAs and DNA payloads, selection of common delivery methods, and genotypic analysis of integration events. We further describe a computational CRISPR RNA design algorithm to avoid potential off-targets, and a CRISPR array cloning pipeline for performing multiplexed DNA insertions. The method presented here allows the isolation of clonal strains containing a novel genomic integration event of interest within 1-2 weeks using available plasmid constructs and standard molecular biology techniques.
Collapse
Affiliation(s)
- Diego Rivera Gelsinger
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
- Department of Systems Biology, Columbia University, New York, NY, USA
| | - Phuc Leo H Vo
- Department of Molecular Pharmacology and Therapeutics, Columbia University, New York, NY, USA
- Vertex Pharmaceuticals, Inc, Boston, MA, USA
| | - Sanne E Klompe
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
- Department of Genomes and Genetics, Institut Pasteur, Paris, France
| | - Carlotta Ronda
- Department of Systems Biology, Columbia University, New York, NY, USA
- Innovative Genomics Institute, University of California Berkeley, Berkeley, CA, USA
| | - Harris H Wang
- Department of Systems Biology, Columbia University, New York, NY, USA
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Samuel H Sternberg
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
| |
Collapse
|
15
|
Zhang J, Li F, Liu D, Liu Q, Song H. Engineering extracellular electron transfer pathways of electroactive microorganisms by synthetic biology for energy and chemicals production. Chem Soc Rev 2024; 53:1375-1446. [PMID: 38117181 DOI: 10.1039/d3cs00537b] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
The excessive consumption of fossil fuels causes massive emission of CO2, leading to climate deterioration and environmental pollution. The development of substitutes and sustainable energy sources to replace fossil fuels has become a worldwide priority. Bio-electrochemical systems (BESs), employing redox reactions of electroactive microorganisms (EAMs) on electrodes to achieve a meritorious combination of biocatalysis and electrocatalysis, provide a green and sustainable alternative approach for bioremediation, CO2 fixation, and energy and chemicals production. EAMs, including exoelectrogens and electrotrophs, perform extracellular electron transfer (EET) (i.e., outward and inward EET), respectively, to exchange energy with the environment, whose rate determines the efficiency and performance of BESs. Therefore, we review the synthetic biology strategies developed in the last decade for engineering EAMs to enhance the EET rate in cell-electrode interfaces for facilitating the production of electricity energy and value-added chemicals, which include (1) progress in genetic manipulation and editing tools to achieve the efficient regulation of gene expression, knockout, and knockdown of EAMs; (2) synthetic biological engineering strategies to enhance the outward EET of exoelectrogens to anodes for electricity power production and anodic electro-fermentation (AEF) for chemicals production, including (i) broadening and strengthening substrate utilization, (ii) increasing the intracellular releasable reducing equivalents, (iii) optimizing c-type cytochrome (c-Cyts) expression and maturation, (iv) enhancing conductive nanowire biosynthesis and modification, (v) promoting electron shuttle biosynthesis, secretion, and immobilization, (vi) engineering global regulators to promote EET rate, (vii) facilitating biofilm formation, and (viii) constructing cell-material hybrids; (3) the mechanisms of inward EET, CO2 fixation pathway, and engineering strategies for improving the inward EET of electrotrophic cells for CO2 reduction and chemical production, including (i) programming metabolic pathways of electrotrophs, (ii) rewiring bioelectrical circuits for enhancing inward EET, and (iii) constructing microbial (photo)electrosynthesis by cell-material hybridization; (4) perspectives on future challenges and opportunities for engineering EET to develop highly efficient BESs for sustainable energy and chemical production. We expect that this review will provide a theoretical basis for the future development of BESs in energy harvesting, CO2 fixation, and chemical synthesis.
Collapse
Affiliation(s)
- Junqi Zhang
- Frontier Science Center for Synthetic Biology (Ministry of Education), Key Laboratory of Systems Bioengineering, and School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
| | - Feng Li
- Frontier Science Center for Synthetic Biology (Ministry of Education), Key Laboratory of Systems Bioengineering, and School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
| | - Dingyuan Liu
- Frontier Science Center for Synthetic Biology (Ministry of Education), Key Laboratory of Systems Bioengineering, and School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
| | - Qijing Liu
- Frontier Science Center for Synthetic Biology (Ministry of Education), Key Laboratory of Systems Bioengineering, and School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
| | - Hao Song
- Frontier Science Center for Synthetic Biology (Ministry of Education), Key Laboratory of Systems Bioengineering, and School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
| |
Collapse
|
16
|
Lampe GD, King RT, Halpin-Healy TS, Klompe SE, Hogan MI, Vo PLH, Tang S, Chavez A, Sternberg SH. Targeted DNA integration in human cells without double-strand breaks using CRISPR-associated transposases. Nat Biotechnol 2024; 42:87-98. [PMID: 36991112 PMCID: PMC10620015 DOI: 10.1038/s41587-023-01748-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 03/13/2023] [Indexed: 03/31/2023]
Abstract
Conventional genome engineering with CRISPR-Cas9 creates double-strand breaks (DSBs) that lead to undesirable byproducts and reduce product purity. Here we report an approach for programmable integration of large DNA sequences in human cells that avoids the generation of DSBs by using Type I-F CRISPR-associated transposases (CASTs). We optimized DNA targeting by the QCascade complex through protein design and developed potent transcriptional activators by exploiting the multi-valent recruitment of the AAA+ ATPase TnsC to genomic sites targeted by QCascade. After initial detection of plasmid-based integration, we screened 15 additional CAST systems from a wide range of bacterial hosts, identified a homolog from Pseudoalteromonas that exhibits improved activity and further increased integration efficiencies. Finally, we discovered that bacterial ClpX enhances genomic integration by multiple orders of magnitude, likely by promoting active disassembly of the post-integration CAST complex, akin to its known role in Mu transposition. Our work highlights the ability to reconstitute complex, multi-component machineries in human cells and establishes a strong foundation to exploit CRISPR-associated transposases for eukaryotic genome engineering.
Collapse
Affiliation(s)
- George D Lampe
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Rebeca T King
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Tyler S Halpin-Healy
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
- Regeneron Pharmaceuticals, Inc., Tarrytown, NY, USA
| | - Sanne E Klompe
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
- Department of Genomes and Genetics, Institut Pasteur, Paris, France
| | - Marcus I Hogan
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Phuc Leo H Vo
- Department of Molecular Pharmacology and Therapeutics, Columbia University, New York, NY, USA
- Vertex Pharmaceuticals, Inc., Boston, MA, USA
| | - Stephen Tang
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Alejandro Chavez
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA
| | - Samuel H Sternberg
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
| |
Collapse
|
17
|
Schmitz M, Querques I. DNA on the move: mechanisms, functions and applications of transposable elements. FEBS Open Bio 2024; 14:13-22. [PMID: 38041553 PMCID: PMC10761935 DOI: 10.1002/2211-5463.13743] [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: 03/27/2023] [Revised: 10/24/2023] [Accepted: 11/30/2023] [Indexed: 12/03/2023] Open
Abstract
Transposons are mobile genetic elements that have invaded all domains of life by moving between and within their host genomes. Due to their mobility (or transposition), transposons facilitate horizontal gene transfer in bacteria and foster the evolution of new molecular functions in prokaryotes and eukaryotes. As transposition can lead to detrimental genomic rearrangements, organisms have evolved a multitude of molecular strategies to control transposons, including genome defense mechanisms provided by CRISPR-Cas systems. Apart from their biological impacts on genomes, DNA transposons have been leveraged as efficient gene insertion vectors in basic research, transgenesis and gene therapy. However, the close to random insertion profile of transposon-based tools limits their programmability and safety. Despite recent advances brought by the development of CRISPR-associated genome editing nucleases, a strategy for efficient insertion of large, multi-kilobase transgenes at user-defined genomic sites is currently challenging. The discovery and experimental characterization of bacterial CRISPR-associated transposons (CASTs) led to the attractive hypothesis that these systems could be repurposed as programmable, site-specific gene integration technologies. Here, we provide a broad overview of the molecular mechanisms underpinning DNA transposition and of its biological and technological impact. The second focus of the article is to describe recent mechanistic and functional analyses of CAST transposition. Finally, current challenges and desired future advances of CAST-based genome engineering applications are briefly discussed.
Collapse
Affiliation(s)
| | - Irma Querques
- Department of BiochemistryUniversity of ZurichSwitzerland
- Max Perutz Labs, Vienna Biocenter Campus (VBC)Austria
- Department of Structural and Computational Biology, Center for Molecular BiologyUniversity of ViennaAustria
| |
Collapse
|
18
|
Tenjo-Castaño F, Montoya G, Carabias A. Transposons and CRISPR: Rewiring Gene Editing. Biochemistry 2023; 62:3521-3532. [PMID: 36130724 PMCID: PMC10734217 DOI: 10.1021/acs.biochem.2c00379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/11/2022] [Indexed: 11/30/2022]
Abstract
CRISPR-Cas is driving a gene editing revolution because of its simple reprogramming. However, off-target effects and dependence on the double-strand break repair pathways impose important limitations. Because homology-directed repair acts primarily in actively dividing cells, many of the current gene correction/replacement approaches are restricted to a minority of cell types. Furthermore, current approaches display low efficiency upon insertion of large DNA cargos (e.g., sequences containing multiple gene circuits with tunable functionalities). Recent research has revealed new links between CRISPR-Cas systems and transposons providing new scaffolds that might overcome some of these limitations. Here, we comment on two new transposon-associated RNA-guided mechanisms considering their potential as new gene editing solutions. Initially, we focus on a group of small RNA-guided endonucleases of the IS200/IS605 family of transposons, which likely evolved into class 2 CRISPR effector nucleases (Cas9s and Cas12s). We explore the diversity of these nucleases (named OMEGA, obligate mobile element-guided activity) and analyze their similarities with class 2 gene editors. OMEGA nucleases can perform gene editing in human cells and constitute promising candidates for the design of new compact RNA-guided platforms. Then, we address the co-option of the RNA-guided activity of different CRISPR effector nucleases by a specialized group of Tn7-like transposons to target transposon integration. We describe the various mechanisms used by these RNA-guided transposons for target site selection and integration. Finally, we assess the potential of these new systems to circumvent some of the current gene editing challenges.
Collapse
Affiliation(s)
- Francisco Tenjo-Castaño
- Structural Molecular Biology Group,
Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3-B, Copenhagen 2200, Denmark
| | - Guillermo Montoya
- Structural Molecular Biology Group,
Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3-B, Copenhagen 2200, Denmark
| | - Arturo Carabias
- Structural Molecular Biology Group,
Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3-B, Copenhagen 2200, Denmark
| |
Collapse
|
19
|
Tou CJ, Kleinstiver BP. Recent Advances in Double-Strand Break-Free Kilobase-Scale Genome Editing Technologies. Biochemistry 2023; 62:3493-3499. [PMID: 36049184 PMCID: PMC10239562 DOI: 10.1021/acs.biochem.2c00311] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Genome editing approaches have transformed the ability to make user-defined changes to genomes in both ex vivo and in vivo contexts. Despite the abundant development of technologies that permit the installation of nucleotide-level changes, until recently, larger-scale sequence edits via technologies independent of DNA double-strand breaks (DSBs) had remained less explored. Here, we review recent advances toward DSB-free technologies that enable kilobase-scale modifications including insertions, deletions, inversions, replacements, and others. These technologies provide new capabilities for users, while offering hope for the simplification of putative therapeutic strategies by moving away from small mutation-specific edits and toward more generalizable kilobase-scale approaches.
Collapse
Affiliation(s)
- Connor J. Tou
- Biological Engineering Program, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Pathology, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Benjamin P. Kleinstiver
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Pathology, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Pathology, Harvard Medical School, Boston, MA, 02115, USA
| |
Collapse
|
20
|
Dhingra Y, Sashital DG. A tool for more specific DNA integration. Science 2023; 382:768-769. [PMID: 37972178 DOI: 10.1126/science.adl0863] [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] [Indexed: 11/19/2023]
Abstract
The efficiency of targeted DNA insertion by CRISPR transposons is improved.
Collapse
Affiliation(s)
- Yukti Dhingra
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, USA
| | - Dipali G Sashital
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, USA
| |
Collapse
|
21
|
George JT, Acree C, Park JU, Kong M, Wiegand T, Pignot YL, Kellogg EH, Greene EC, Sternberg SH. Mechanism of target site selection by type V-K CRISPR-associated transposases. Science 2023; 382:eadj8543. [PMID: 37972161 PMCID: PMC10771339 DOI: 10.1126/science.adj8543] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 09/23/2023] [Indexed: 11/19/2023]
Abstract
CRISPR-associated transposases (CASTs) repurpose nuclease-deficient CRISPR effectors to catalyze RNA-guided transposition of large genetic payloads. Type V-K CASTs offer potential technology advantages but lack accuracy, and the molecular basis for this drawback has remained elusive. Here, we reveal that type V-K CASTs maintain an RNA-independent, "untargeted" transposition pathway alongside RNA-dependent integration, driven by the local availability of TnsC filaments. Using cryo-electron microscopy, single-molecule experiments, and high-throughput sequencing, we found that a minimal, CRISPR-less transpososome preferentially directs untargeted integration at AT-rich sites, with additional local specificity imparted by TnsB. By exploiting this knowledge, we suppressed untargeted transposition and increased type V-K CAST specificity up to 98.1% in cells without compromising on-target integration efficiency. These findings will inform further engineering of CAST systems for accurate, kilobase-scale genome engineering applications.
Collapse
Affiliation(s)
- Jerrin Thomas George
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Christopher Acree
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Jung-Un Park
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Muwen Kong
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Tanner Wiegand
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Yanis Luca Pignot
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Elizabeth H. Kellogg
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Eric C. Greene
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Samuel H. Sternberg
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| |
Collapse
|
22
|
Wang S, Gabel C, Siddique R, Klose T, Chang L. Molecular mechanism for Tn7-like transposon recruitment by a type I-B CRISPR effector. Cell 2023; 186:4204-4215.e19. [PMID: 37557170 PMCID: PMC11027886 DOI: 10.1016/j.cell.2023.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 04/23/2023] [Accepted: 07/10/2023] [Indexed: 08/11/2023]
Abstract
Tn7-like transposons have co-opted CRISPR-Cas systems to facilitate the movement of their own DNA. These CRISPR-associated transposons (CASTs) are promising tools for programmable gene knockin. A key feature of CASTs is their ability to recruit Tn7-like transposons to nuclease-deficient CRISPR effectors. However, how Tn7-like transposons are recruited by diverse CRISPR effectors remains poorly understood. Here, we present the cryo-EM structure of a recruitment complex comprising the Cascade complex, TniQ, TnsC, and the target DNA in the type I-B CAST from Peltigera membranacea cyanobiont 210A. Target DNA recognition by Cascade induces conformational changes in Cas6 and primes TniQ recruitment through its C-terminal domain. The N-terminal domain of TniQ is bound to the seam region of the TnsC spiral heptamer. Our findings provide insights into the diverse mechanisms for the recruitment of Tn7-like transposons to CRISPR effectors and will aid in the development of CASTs as gene knockin tools.
Collapse
Affiliation(s)
- Shukun Wang
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Clinton Gabel
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Romana Siddique
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Thomas Klose
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Leifu Chang
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; Purdue Institute for Cancer Research, Purdue University, West Lafayette, IN 47907, USA.
| |
Collapse
|
23
|
George JT, Acree C, Park JU, Kong M, Wiegand T, Pignot YL, Kellogg EH, Greene EC, Sternberg SH. Mechanism of target site selection by type V-K CRISPR-associated transposases. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.14.548620. [PMID: 37503092 PMCID: PMC10370016 DOI: 10.1101/2023.07.14.548620] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Unlike canonical CRISPR-Cas systems that rely on RNA-guided nucleases for target cleavage, CRISPR-associated transposases (CASTs) repurpose nuclease-deficient CRISPR effectors to facilitate RNA-guided transposition of large genetic payloads. Type V-K CASTs offer several potential upsides for genome engineering, due to their compact size, easy programmability, and unidirectional integration. However, these systems are substantially less accurate than type I-F CASTs, and the molecular basis for this difference has remained elusive. Here we reveal that type V-K CASTs undergo two distinct mobilization pathways with remarkably different specificities: RNA-dependent and RNA-independent transposition. Whereas RNA-dependent transposition relies on Cas12k for accurate target selection, RNA-independent integration events are untargeted and primarily driven by the local availability of TnsC filaments. The cryo-EM structure of the untargeted complex reveals a TnsB-TnsC-TniQ transpososome that encompasses two turns of a TnsC filament and otherwise resembles major architectural aspects of the Cas12k-containing transpososome. Using single-molecule experiments and genome-wide meta-analyses, we found that AT-rich sites are preferred substrates for untargeted transposition and that the TnsB transposase also imparts local specificity, which collectively determine the precise insertion site. Knowledge of these motifs allowed us to direct untargeted transposition events to specific hotspot regions of a plasmid. Finally, by exploiting TnsB's preference for on-target integration and modulating the availability of TnsC, we suppressed RNA-independent transposition events and increased type V-K CAST specificity up to 98.1%, without compromising the efficiency of on-target integration. Collectively, our results reveal the importance of dissecting target site selection mechanisms and highlight new opportunities to leverage CAST systems for accurate, kilobase-scale genome engineering applications.
Collapse
Affiliation(s)
- Jerrin Thomas George
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Christopher Acree
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
- Present address: Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37212, USA
| | - Jung-Un Park
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
- Future address: Department of Structural Biology. St Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Muwen Kong
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Tanner Wiegand
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Yanis Luca Pignot
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
- Present address: Department of Biochemistry, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Elizabeth H. Kellogg
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
- Future address: Department of Structural Biology. St Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Eric C. Greene
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Samuel H. Sternberg
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| |
Collapse
|
24
|
Zeng T, Yin J, Liu Z, Li Z, Zhang Y, Lv Y, Lu ML, Luo M, Chen M, Xiao Y. Mechanistic insights into transposon cleavage and integration by TnsB of ShCAST system. Cell Rep 2023; 42:112698. [PMID: 37379212 DOI: 10.1016/j.celrep.2023.112698] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 04/02/2023] [Accepted: 06/09/2023] [Indexed: 06/30/2023] Open
Abstract
The type V-K CRISPR-associated transposons (CASTs) allow RNA-guided DNA integration and have great potential as a programmable site-specific gene insertion tool. Although all core components have been independently characterized structurally, the mechanism of how the transposase TnsB associates with AAA+ ATPase TnsC and catalyzes donor DNA cleavage and integration remains ambiguous. In this study, we demonstrate that TniQ-dCas9 fusion can direct site-specific transposition by TnsB/TnsC in ShCAST. TnsB is a 3'-5' exonuclease that specifically cleaves donor DNA at the end of the terminal repeats and integrates the left end prior to the right end. The nucleotide preference and the cleavage site of TnsB are markedly different from those of the well-documented MuA. We also find that TnsB/TnsC association is enhanced in a half-integration state. Overall, our results provide valuable insights into the mechanism and application expansion of CRISPR-mediated site-specific transposition by TnsB/TnsC.
Collapse
Affiliation(s)
- Ting Zeng
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China; Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Jie Yin
- Department of Biochemistry, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China
| | - Ziwen Liu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China; Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Zhaoxing Li
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China; Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Yu Zhang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China; Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Yang Lv
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China; Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Mei-Ling Lu
- Department of Biochemistry, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China
| | - Min Luo
- Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Meirong Chen
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China; Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China.
| | - Yibei Xiao
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China; Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China; Chongqing Innovation Institute of China Pharmaceutical University, Chongqing 401135, China.
| |
Collapse
|
25
|
Park JU, Petassi MT, Hsieh SC, Mehrotra E, Schuler G, Budhathoki J, Truong VH, Thyme SB, Ke A, Kellogg EH, Peters JE. Multiple adaptations underly co-option of a CRISPR surveillance complex for RNA-guided DNA transposition. Mol Cell 2023; 83:1827-1838.e6. [PMID: 37267904 PMCID: PMC10693918 DOI: 10.1016/j.molcel.2023.05.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 02/23/2023] [Accepted: 05/03/2023] [Indexed: 06/04/2023]
Abstract
CRISPR-associated transposons (CASTs) are natural RNA-directed transposition systems. We demonstrate that transposon protein TniQ plays a central role in promoting R-loop formation by RNA-guided DNA-targeting modules. TniQ residues, proximal to CRISPR RNA (crRNA), are required for recognizing different crRNA categories, revealing an unappreciated role of TniQ to direct transposition into different classes of crRNA targets. To investigate adaptations allowing CAST elements to utilize attachment sites inaccessible to CRISPR-Cas surveillance complexes, we compared and contrasted PAM sequence requirements in both I-F3b CAST and I-F1 CRISPR-Cas systems. We identify specific amino acids that enable a wider range of PAM sequences to be accommodated in I-F3b CAST elements compared with I-F1 CRISPR-Cas, enabling CAST elements to access attachment sites as sequences drift and evade host surveillance. Together, this evidence points to the central role of TniQ in facilitating the acquisition of CRISPR effector complexes for RNA-guided DNA transposition.
Collapse
Affiliation(s)
- Jung-Un Park
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Michael T Petassi
- Department of Microbiology, Cornell University, Ithaca, NY 14853, USA
| | - Shan-Chi Hsieh
- Department of Microbiology, Cornell University, Ithaca, NY 14853, USA
| | - Eshan Mehrotra
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Gabriel Schuler
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Jagat Budhathoki
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Vinh H Truong
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Summer B Thyme
- Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Ailong Ke
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Elizabeth H Kellogg
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA.
| | - Joseph E Peters
- Department of Microbiology, Cornell University, Ithaca, NY 14853, USA.
| |
Collapse
|
26
|
Faure G, Saito M, Benler S, Peng I, Wolf YI, Strecker J, Altae-Tran H, Neumann E, Li D, Makarova KS, Macrae RK, Koonin EV, Zhang F. Modularity and diversity of target selectors in Tn7 transposons. Mol Cell 2023:S1097-2765(23)00367-2. [PMID: 37267947 DOI: 10.1016/j.molcel.2023.05.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 01/17/2023] [Accepted: 05/09/2023] [Indexed: 06/04/2023]
Abstract
To spread, transposons must integrate into target sites without disruption of essential genes while avoiding host defense systems. Tn7-like transposons employ multiple mechanisms for target-site selection, including protein-guided targeting and, in CRISPR-associated transposons (CASTs), RNA-guided targeting. Combining phylogenomic and structural analyses, we conducted a broad survey of target selectors, revealing diverse mechanisms used by Tn7 to recognize target sites, including previously uncharacterized target-selector proteins found in newly discovered transposable elements (TEs). We experimentally characterized a CAST I-D system and a Tn6022-like transposon that uses TnsF, which contains an inactivated tyrosine recombinase domain, to target the comM gene. Additionally, we identified a non-Tn7 transposon, Tsy, encoding a homolog of TnsF with an active tyrosine recombinase domain, which we show also inserts into comM. Our findings show that Tn7 transposons employ modular architecture and co-opt target selectors from various sources to optimize target selection and drive transposon spread.
Collapse
Affiliation(s)
- Guilhem Faure
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Makoto Saito
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Sean Benler
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD 20894, USA
| | - Iris Peng
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Yuri I Wolf
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD 20894, USA
| | - Jonathan Strecker
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Han Altae-Tran
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Edwin Neumann
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - David Li
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Kira S Makarova
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD 20894, USA
| | - Rhiannon K Macrae
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD 20894, USA.
| | - Feng Zhang
- Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| |
Collapse
|
27
|
Alalmaie A, Diaf S, Khashan R. Insight into the molecular mechanism of the transposon-encoded type I-F CRISPR-Cas system. J Genet Eng Biotechnol 2023; 21:60. [PMID: 37191877 DOI: 10.1186/s43141-023-00507-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 04/20/2023] [Indexed: 05/17/2023]
Abstract
CRISPR-Cas9 is a popular gene-editing tool that allows researchers to introduce double-strand breaks to edit parts of the genome. CRISPR-Cas9 system is used more than other gene-editing tools because it is simple and easy to customize. However, Cas9 may produce unintended double-strand breaks in DNA, leading to off-target effects. There have been many improvements in the CRISPR-Cas system to control the off-target effect and improve the efficiency. The presence of a nuclease-deficient CRISPR-Cas system in several bacterial Tn7-like transposons inspires researchers to repurpose to direct the insertion of Tn7-like transposons instead of cleaving the target DNA, which will eventually limit the risk of off-target effects. Two transposon-encoded CRISPR-Cas systems have been experimentally confirmed. The first system, found in Tn7 like-transposon (Tn6677), is associated with the variant type I-F CRISPR-Cas system. The second one, found in Tn7 like-transposon (Tn5053), is related to the variant type V-K CRISPR-Cas system. This review describes the molecular and structural mechanisms of DNA targeting by the transposon-encoded type I-F CRISPR-Cas system, from assembly around the CRISPR-RNA (crRNA) to the initiation of transposition.
Collapse
Affiliation(s)
- Amnah Alalmaie
- Department of Pharmaceutical Sciences, Philadelphia College of Pharmacy, Saint Joseph University, Philadelphia, PA, 19131, USA
| | - Saousen Diaf
- Department of Pharmaceutical Sciences, Philadelphia College of Pharmacy, Saint Joseph University, Philadelphia, PA, 19131, USA
| | - Raed Khashan
- Department of Pharmaceutical Sciences, Division of Pharmaceutical Sciences, Long Island University, Brooklyn, NY, 11201, USA.
| |
Collapse
|
28
|
Gelsinger DR, Vo PLH, Klompe SE, Ronda C, Wang H, Sternberg SH. Bacterial genome engineering using CRISPR RNA-guided transposases. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.18.533263. [PMID: 36993567 PMCID: PMC10055292 DOI: 10.1101/2023.03.18.533263] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
Abstract
CRISPR-associated transposons (CASTs) have the potential to transform the technology landscape for kilobase-scale genome engineering, by virtue of their ability to integrate large genetic payloads with high accuracy, easy programmability, and no requirement for homologous recombination machinery. These transposons encode efficient, CRISPR RNA-guided transposases that execute genomic insertions in E. coli at efficiencies approaching ~100%, generate multiplexed edits when programmed with multiple guides, and function robustly in diverse Gram-negative bacterial species. Here we present a detailed protocol for engineering bacterial genomes using CAST systems, including guidelines on the available homologs and vectors, customization of guide RNAs and DNA payloads, selection of common delivery methods, and genotypic analysis of integration events. We further describe a computational crRNA design algorithm to avoid potential off-targets and CRISPR array cloning pipeline for DNA insertion multiplexing. Starting from available plasmid constructs, the isolation of clonal strains containing a novel genomic integration event-of-interest can be achieved in 1 week using standard molecular biology techniques.
Collapse
Affiliation(s)
- Diego R Gelsinger
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Phuc Leo H Vo
- Department of Molecular Pharmacology and Therapeutics, Columbia University, New York, NY, USA
| | - Sanne E Klompe
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Carlotta Ronda
- Department of Systems Biology, Columbia University, New York, NY, USA
| | - Harris Wang
- Department of Systems Biology, Columbia University, New York, NY, USA
| | - Samuel H Sternberg
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| |
Collapse
|
29
|
Lampe GD, King RT, Halpin-Healy TS, Klompe SE, Hogan MI, Vo PLH, Tang S, Chavez A, Sternberg SH. Targeted DNA integration in human cells without double-strand breaks using CRISPR RNA-guided transposases. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.17.533036. [PMID: 36993517 PMCID: PMC10055298 DOI: 10.1101/2023.03.17.533036] [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: 06/19/2023]
Abstract
Traditional genome-editing reagents such as CRISPR-Cas9 achieve targeted DNA modification by introducing double-strand breaks (DSBs), thereby stimulating localized DNA repair by endogenous cellular repair factors. While highly effective at generating heterogenous knockout mutations, this approach suffers from undesirable byproducts and an inability to control product purity. Here we develop a system in human cells for programmable, DSB-free DNA integration using Type I CRISPR-associated transposons (CASTs). To adapt our previously described CAST systems, we optimized DNA targeting by the QCascade complex through a comprehensive assessment of protein design, and we developed potent transcriptional activators by exploiting the multi-valent recruitment of the AAA+ ATPase, TnsC, to genomic sites targeted by QCascade. After initial detection of plasmid-based transposition, we screened 15 homologous CAST systems from a wide range of bacterial hosts, identified a CAST homolog from Pseudoalteromonas that exhibited improved activity, and increased integration efficiencies through parameter optimization. We further discovered that bacterial ClpX enhances genomic integration by multiple orders of magnitude, and we propose that this critical accessory factor functions to drive active disassembly of the post-transposition CAST complex, akin to its demonstrated role in Mu transposition. Our work highlights the ability to functionally reconstitute complex, multi-component machineries in human cells, and establishes a strong foundation to realize the full potential of CRISPR-associated transposons for human genome engineering.
Collapse
Affiliation(s)
- George D Lampe
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Rebeca T King
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Tyler S Halpin-Healy
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Sanne E Klompe
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Marcus I Hogan
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Phuc Leo H Vo
- Department of Molecular Pharmacology and Therapeutics, Columbia University, New York, NY, USA
| | - Stephen Tang
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Alejandro Chavez
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Samuel H Sternberg
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| |
Collapse
|
30
|
Metabolic engineering of Escherichia coli to enhance protein production by coupling ShCAST-based optimized transposon system and CRISPR interference. J Taiwan Inst Chem Eng 2023. [DOI: 10.1016/j.jtice.2023.104746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
|
31
|
Ziemann M, Reimann V, Liang Y, Shi Y, Ma H, Xie Y, Li H, Zhu T, Lu X, Hess WR. CvkR is a MerR-type transcriptional repressor of class 2 type V-K CRISPR-associated transposase systems. Nat Commun 2023; 14:924. [PMID: 36801863 PMCID: PMC9938897 DOI: 10.1038/s41467-023-36542-9] [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: 05/27/2022] [Accepted: 02/06/2023] [Indexed: 02/20/2023] Open
Abstract
Certain CRISPR-Cas elements integrate into Tn7-like transposons, forming CRISPR-associated transposon (CAST) systems. How the activity of these systems is controlled in situ has remained largely unknown. Here we characterize the MerR-type transcriptional regulator Alr3614 that is encoded by one of the CAST (AnCAST) system genes in the genome of cyanobacterium Anabaena sp. PCC 7120. We identify a number of Alr3614 homologs across cyanobacteria and suggest naming these regulators CvkR for Cas V-K repressors. Alr3614/CvkR is translated from leaderless mRNA and represses the AnCAST core modules cas12k and tnsB directly, and indirectly the abundance of the tracr-CRISPR RNA. We identify a widely conserved CvkR binding motif 5'-AnnACATnATGTnnT-3'. Crystal structure of CvkR at 1.6 Å resolution reveals that it comprises distinct dimerization and potential effector-binding domains and that it assembles into a homodimer, representing a discrete structural subfamily of MerR regulators. CvkR repressors are at the core of a widely conserved regulatory mechanism that controls type V-K CAST systems.
Collapse
Affiliation(s)
- Marcus Ziemann
- Faculty of Biology, Institute of Biology III, Genetics and Experimental Bioinformatics, University of Freiburg, Schänzlestr. 1, Freiburg, D-79104, Germany
| | - Viktoria Reimann
- Faculty of Biology, Institute of Biology III, Genetics and Experimental Bioinformatics, University of Freiburg, Schänzlestr. 1, Freiburg, D-79104, Germany
| | - Yajing Liang
- Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT), Chinese Academy of Sciences, No.189 Songling Road, Qingdao, 266101, China.,Shandong Energy Institute, Qingdao, 266101, China.,Qingdao New Energy Shandong Laboratory, Qingdao, 266101, China
| | - Yue Shi
- Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT), Chinese Academy of Sciences, No.189 Songling Road, Qingdao, 266101, China.,Shandong Energy Institute, Qingdao, 266101, China.,Qingdao New Energy Shandong Laboratory, Qingdao, 266101, China
| | - Honglei Ma
- Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT), Chinese Academy of Sciences, No.189 Songling Road, Qingdao, 266101, China.,Shandong Energy Institute, Qingdao, 266101, China.,Qingdao New Energy Shandong Laboratory, Qingdao, 266101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yuman Xie
- Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT), Chinese Academy of Sciences, No.189 Songling Road, Qingdao, 266101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hui Li
- Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT), Chinese Academy of Sciences, No.189 Songling Road, Qingdao, 266101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Tao Zhu
- Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT), Chinese Academy of Sciences, No.189 Songling Road, Qingdao, 266101, China. .,Shandong Energy Institute, Qingdao, 266101, China. .,Qingdao New Energy Shandong Laboratory, Qingdao, 266101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Xuefeng Lu
- Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT), Chinese Academy of Sciences, No.189 Songling Road, Qingdao, 266101, China. .,Shandong Energy Institute, Qingdao, 266101, China. .,Qingdao New Energy Shandong Laboratory, Qingdao, 266101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China. .,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China.
| | - Wolfgang R Hess
- Faculty of Biology, Institute of Biology III, Genetics and Experimental Bioinformatics, University of Freiburg, Schänzlestr. 1, Freiburg, D-79104, Germany.
| |
Collapse
|
32
|
Hsieh SC, Peters JE. Discovery and characterization of novel type I-D CRISPR-guided transposons identified among diverse Tn7-like elements in cyanobacteria. Nucleic Acids Res 2023; 51:765-782. [PMID: 36537206 PMCID: PMC9881144 DOI: 10.1093/nar/gkac1216] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 12/01/2022] [Accepted: 12/06/2022] [Indexed: 12/24/2022] Open
Abstract
CRISPR-Cas defense systems have been naturally coopted for guide RNA-directed transposition by Tn7 family bacterial transposons. We find cyanobacterial genomes are rich in Tn7-like elements, including most of the known guide RNA-directed transposons, the type V-K, I-B1, and I-B2 CRISPR-Cas based systems. We discovered and characterized an example of a type I-D CRISPR-Cas system which was naturally coopted for guide RNA-directed transposition. Multiple novel adaptations were found specific to the I-D subtype, including natural inactivation of the Cas10 nuclease. The type I-D CRISPR-Cas transposition system showed flexibility in guide RNA length requirements and could be engineered to function with ribozyme-based self-processing guide RNAs removing the requirement for Cas6 in the heterologous system. The type I-D CRISPR-Cas transposon also has naturally fused transposase proteins that are functional for cut-and-paste transposition. Multiple attributes of the type I-D system offer unique possibilities for future work in gene editing. Our bioinformatic analysis also revealed a broader understanding of the evolution of Tn7-like elements. Extensive swapping of targeting systems was identified among Tn7-like elements in cyanobacteria and multiple examples of convergent evolution, including systems targeting integration into genes required for natural transformation.
Collapse
Affiliation(s)
- Shan-Chi Hsieh
- Department of Microbiology, Cornell University, Ithaca, NY 14853 USA
| | - Joseph E Peters
- Department of Microbiology, Cornell University, Ithaca, NY 14853 USA
| |
Collapse
|
33
|
Precise cut-and-paste DNA insertion using engineered type V-K CRISPR-associated transposases. Nat Biotechnol 2023:10.1038/s41587-022-01574-x. [PMID: 36593413 DOI: 10.1038/s41587-022-01574-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 10/14/2022] [Indexed: 01/03/2023]
Abstract
CRISPR-associated transposases (CASTs) enable recombination-independent, multi-kilobase DNA insertions at RNA-programmed genomic locations. However, the utility of type V-K CASTs is hindered by high off-target integration and a transposition mechanism that results in a mixture of desired simple cargo insertions and undesired plasmid cointegrate products. Here we overcome both limitations by engineering new CASTs with improved integration product purity and genome-wide specificity. To do so, we engineered a nicking homing endonuclease fusion to TnsB (named HELIX) to restore the 5' nicking capability needed for cargo excision on the DNA donor. HELIX enables cut-and-paste DNA insertion with up to 99.4% simple insertion product purity, while retaining robust integration efficiencies on genomic targets. HELIX has substantially higher on-target specificity than canonical CASTs, and we identify several novel factors that further regulate targeted and genome-wide integration. Finally, we extend HELIX to other type V-K orthologs and demonstrate the feasibility of HELIX-mediated integration in human cell contexts.
Collapse
|
34
|
First full views of a CRISPR-guided system for gene insertion. Nature 2023; 613:634-635. [PMID: 36631579 DOI: 10.1038/d41586-022-04584-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
35
|
Park JU, Tsai AWL, Rizo AN, Truong VH, Wellner TX, Schargel RD, Kellogg EH. Structures of the holo CRISPR RNA-guided transposon integration complex. Nature 2023; 613:775-782. [PMID: 36442503 PMCID: PMC9876797 DOI: 10.1038/s41586-022-05573-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/17/2022] [Indexed: 11/30/2022]
Abstract
CRISPR-associated transposons (CAST) are programmable mobile genetic elements that insert large DNA cargos using an RNA-guided mechanism1-3. CAST elements contain multiple conserved proteins: a CRISPR effector (Cas12k or Cascade), a AAA+ regulator (TnsC), a transposase (TnsA-TnsB) and a target-site-associated factor (TniQ). These components are thought to cooperatively integrate DNA via formation of a multisubunit transposition integration complex (transpososome). Here we reconstituted the approximately 1 MDa type V-K CAST transpososome from Scytonema hofmannii (ShCAST) and determined its structure using single-particle cryo-electon microscopy. The architecture of this transpososome reveals modular association between the components. Cas12k forms a complex with ribosomal subunit S15 and TniQ, stabilizing formation of a full R-loop. TnsC has dedicated interaction interfaces with TniQ and TnsB. Of note, we observe TnsC-TnsB interactions at the C-terminal face of TnsC, which contribute to the stimulation of ATPase activity. Although the TnsC oligomeric assembly deviates slightly from the helical configuration found in isolation, the TnsC-bound target DNA conformation differs markedly in the transpososome. As a consequence, TnsC makes new protein-DNA interactions throughout the transpososome that are important for transposition activity. Finally, we identify two distinct transpososome populations that differ in their DNA contacts near TniQ. This suggests that associations with the CRISPR effector can be flexible. This ShCAST transpososome structure enhances our understanding of CAST transposition systems and suggests ways to improve CAST transposition for precision genome-editing applications.
Collapse
Affiliation(s)
- Jung-Un Park
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Amy Wei-Lun Tsai
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Alexandrea N Rizo
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Vinh H Truong
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Tristan X Wellner
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Richard D Schargel
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Elizabeth H Kellogg
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA.
| |
Collapse
|
36
|
Schmitz M, Querques I, Oberli S, Chanez C, Jinek M. Structural basis for the assembly of the type V CRISPR-associated transposon complex. Cell 2022; 185:4999-5010.e17. [PMID: 36435179 PMCID: PMC9798831 DOI: 10.1016/j.cell.2022.11.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 09/26/2022] [Accepted: 11/09/2022] [Indexed: 11/27/2022]
Abstract
CRISPR-Cas systems have been co-opted by Tn7-like transposable elements to direct RNA-guided transposition. Type V-K CRISPR-associated transposons rely on the concerted activities of the pseudonuclease Cas12k, the AAA+ ATPase TnsC, the Zn-finger protein TniQ, and the transposase TnsB. Here we present a cryo-electron microscopic structure of a target DNA-bound Cas12k-transposon recruitment complex comprised of RNA-guided Cas12k, TniQ, a polymeric TnsC filament and, unexpectedly, the ribosomal protein S15. Complex assembly, mediated by a network of interactions involving the guide RNA, TniQ, and S15, results in R-loop completion. TniQ contacts two TnsC protomers at the Cas12k-proximal filament end, likely nucleating its polymerization. Transposition activity assays corroborate our structural findings, implying that S15 is a bona fide component of the type V crRNA-guided transposon machinery. Altogether, our work uncovers key mechanistic aspects underpinning RNA-mediated assembly of CRISPR-associated transposons to guide their development as programmable tools for site-specific insertion of large DNA payloads.
Collapse
Affiliation(s)
- Michael Schmitz
- Department of Biochemistry, University of Zurich, Zurich 8057, Switzerland
| | - Irma Querques
- Department of Biochemistry, University of Zurich, Zurich 8057, Switzerland
| | - Seraina Oberli
- Department of Biochemistry, University of Zurich, Zurich 8057, Switzerland
| | - Christelle Chanez
- Department of Biochemistry, University of Zurich, Zurich 8057, Switzerland
| | - Martin Jinek
- Department of Biochemistry, University of Zurich, Zurich 8057, Switzerland.
| |
Collapse
|
37
|
Wang JY, Pausch P, Doudna JA. Structural biology of CRISPR-Cas immunity and genome editing enzymes. Nat Rev Microbiol 2022; 20:641-656. [PMID: 35562427 DOI: 10.1038/s41579-022-00739-4] [Citation(s) in RCA: 62] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/11/2022] [Indexed: 12/20/2022]
Abstract
CRISPR-Cas systems provide resistance against foreign mobile genetic elements and have a wide range of genome editing and biotechnological applications. In this Review, we examine recent advances in understanding the molecular structures and mechanisms of enzymes comprising bacterial RNA-guided CRISPR-Cas immune systems and deployed for wide-ranging genome editing applications. We explore the adaptive and interference aspects of CRISPR-Cas function as well as open questions about the molecular mechanisms responsible for genome targeting. These structural insights reflect close evolutionary links between CRISPR-Cas systems and mobile genetic elements, including the origins and evolution of CRISPR-Cas systems from DNA transposons, retrotransposons and toxin-antitoxin modules. We discuss how the evolution and structural diversity of CRISPR-Cas systems explain their functional complexity and utility as genome editing tools.
Collapse
Affiliation(s)
- Joy Y Wang
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Patrick Pausch
- VU LSC-EMBL Partnership for Genome Editing Technologies, Life Sciences Center, Vilnius University, Vilnius, Lithuania.
| | - Jennifer A Doudna
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA.
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA.
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, USA.
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA.
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, CA, USA.
- MBIB Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Gladstone Institutes, University of California, San Francisco, San Francisco, CA, USA.
- Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA.
| |
Collapse
|
38
|
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.
Collapse
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.
| |
Collapse
|
39
|
Mitrofanov A, Ziemann M, Alkhnbashi OS, Hess WR, Backofen R. CRISPRtracrRNA: robust approach for CRISPR tracrRNA detection. Bioinformatics 2022; 38:ii42-ii48. [PMID: 36124799 PMCID: PMC9486595 DOI: 10.1093/bioinformatics/btac466] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
MOTIVATION The CRISPR-Cas9 system is a Type II CRISPR system that has rapidly become the most versatile and widespread tool for genome engineering. It consists of two components, the Cas9 effector protein, and a single guide RNA that combines the spacer (for identifying the target) with the tracrRNA, a trans-activating small RNA required for both crRNA maturation and interference. While there are well-established methods for screening Cas effector proteins and CRISPR arrays, the detection of tracrRNA remains the bottleneck in detecting Class 2 CRISPR systems. RESULTS We introduce a new pipeline CRISPRtracrRNA for screening and evaluation of tracrRNA candidates in genomes. This pipeline combines evidence from different components of the Cas9-sgRNA complex. The core is a newly developed structural model via covariance models from a sequence-structure alignment of experimentally validated tracrRNAs. As additional evidence, we determine the terminator signal (required for the tracrRNA transcription) and the RNA-RNA interaction between the CRISPR array repeat and the 5'-part of the tracrRNA. Repeats are detected via an ML-based approach (CRISPRidenify). Providing further evidence, we detect the cassette containing the Cas9 (Type II CRISPR systems) and Cas12 (Type V CRISPR systems) effector protein. Our tool is the first for detecting tracrRNA for Type V systems. AVAILABILITY AND IMPLEMENTATION The implementation of the CRISPRtracrRNA is available on GitHub upon requesting the access permission, (https://github.com/BackofenLab/CRISPRtracrRNA). Data generated in this study can be obtained upon request to the corresponding person: Rolf Backofen (backofen@informatik.uni-freiburg.de). SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
Collapse
Affiliation(s)
| | | | | | - Wolfgang R Hess
- Faculty of Biology, Genetics and Experimental Bioinformatics, University of Freiburg, Freiburg, Germany
| | | |
Collapse
|
40
|
Hoffmann FT, Kim M, Beh LY, Wang J, Vo PLH, Gelsinger DR, George JT, Acree C, Mohabir JT, Fernández IS, Sternberg SH. Selective TnsC recruitment enhances the fidelity of RNA-guided transposition. Nature 2022; 609:384-393. [PMID: 36002573 PMCID: PMC10583602 DOI: 10.1038/s41586-022-05059-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 06/29/2022] [Indexed: 01/25/2023]
Abstract
Bacterial transposons are pervasive mobile genetic elements that use distinct DNA-binding proteins for horizontal transmission. For example, Escherichia coli Tn7 homes to a specific attachment site using TnsD1, whereas CRISPR-associated transposons use type I or type V Cas effectors to insert downstream of target sites specified by guide RNAs2,3. Despite this targeting diversity, transposition invariably requires TnsB, a DDE-family transposase that catalyses DNA excision and insertion, and TnsC, a AAA+ ATPase that is thought to communicate between transposase and targeting proteins4. How TnsC mediates this communication and thereby regulates transposition fidelity has remained unclear. Here we use chromatin immunoprecipitation with sequencing to monitor in vivo formation of the type I-F RNA-guided transpososome, enabling us to resolve distinct protein recruitment events before integration. DNA targeting by the TniQ-Cascade complex is surprisingly promiscuous-hundreds of genomic off-target sites are sampled, but only a subset of those sites is licensed for TnsC and TnsB recruitment, revealing a crucial proofreading checkpoint. To advance the mechanistic understanding of interactions responsible for transpososome assembly, we determined structures of TnsC using cryogenic electron microscopy and found that ATP binding drives the formation of heptameric rings that thread DNA through the central pore, thereby positioning the substrate for downstream integration. Collectively, our results highlight the molecular specificity imparted by consecutive factor binding to genomic target sites during RNA-guided transposition, and provide a structural roadmap to guide future engineering efforts.
Collapse
Affiliation(s)
- Florian T Hoffmann
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Minjoo Kim
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
- Department of Biomedical Engineering, New York University Tandon School of Engineering, New York, NY, USA
| | - Leslie Y Beh
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
- Illumina Singapore Pte, Ltd., Singapore, Singapore
| | - Jing Wang
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
- The National Resource for Automated Molecular Microscopy, Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
| | - Phuc Leo H Vo
- Department of Molecular Pharmacology and Therapeutics, Columbia University, New York, NY, USA
- Vertex Pharmaceuticals, Boston, MA, USA
| | - Diego R Gelsinger
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Jerrin Thomas George
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Christopher Acree
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Jason T Mohabir
- Department of Computer Science, Columbia University, New York, NY, USA
- Genomic Center for Infectious Diseases, Broad Institute, Cambridge, MA, USA
| | - Israel S Fernández
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, USA.
| | - Samuel H Sternberg
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
| |
Collapse
|
41
|
Park JU, Tsai AWL, Chen TH, Peters JE, Kellogg EH. Mechanistic details of CRISPR-associated transposon recruitment and integration revealed by cryo-EM. Proc Natl Acad Sci U S A 2022; 119:e2202590119. [PMID: 35914146 PMCID: PMC9371665 DOI: 10.1073/pnas.2202590119] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 06/04/2022] [Indexed: 11/18/2022] Open
Abstract
CRISPR-associated transposons (CASTs) are Tn7-like elements that are capable of RNA-guided DNA integration. Although structural data are known for nearly all core transposition components, the transposase component, TnsB, remains uncharacterized. Using cryo-electron microscopy (cryo-EM) structure determination, we reveal the conformation of TnsB during transposon integration for the type V-K CAST system from Scytonema hofmanni (ShCAST). Our structure of TnsB is a tetramer, revealing strong mechanistic relationships with the overall architecture of RNaseH transposases/integrases in general, and in particular the MuA transposase from bacteriophage Mu. However, key structural differences in the C-terminal domains indicate that TnsB's tetrameric architecture is stabilized by a different set of protein-protein interactions compared with MuA. We describe the base-specific interactions along the TnsB binding site, which explain how different CAST elements can function on cognate mobile elements independent of one another. We observe that melting of the 5' nontransferred strand of the transposon end is a structural feature stabilized by TnsB and furthermore is crucial for donor-DNA integration. Although not observed in the TnsB strand-transfer complex, the C-terminal end of TnsB serves a crucial role in transposase recruitment to the target site. The C-terminal end of TnsB adopts a short, structured 15-residue "hook" that decorates TnsC filaments. Unlike full-length TnsB, C-terminal fragments do not appear to stimulate filament disassembly using two different assays, suggesting that additional interactions between TnsB and TnsC are required for redistributing TnsC to appropriate targets. The structural information presented here will help guide future work in modifying these important systems as programmable gene integration tools.
Collapse
Affiliation(s)
- Jung-Un Park
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Amy Wei-Lun Tsai
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Tiffany H Chen
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| | - Joseph E Peters
- Department of Microbiology, Cornell University, Ithaca, NY 14853
| | - Elizabeth H Kellogg
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853
| |
Collapse
|
42
|
Cheng ZH, Wu J, Liu JQ, Min D, Liu DF, Li WW, Yu HQ. Repurposing CRISPR RNA-guided integrases system for one-step, efficient genomic integration of ultra-long DNA sequences. Nucleic Acids Res 2022; 50:7739-7750. [PMID: 35776123 PMCID: PMC9303307 DOI: 10.1093/nar/gkac554] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 06/14/2022] [Accepted: 06/16/2022] [Indexed: 01/26/2023] Open
Abstract
Genomic integration techniques offer opportunities for generation of engineered microorganisms with improved or even entirely new functions but are currently limited by inability for efficient insertion of long genetic payloads due to multiplexing. Herein, using Shewanella oneidensis MR-1 as a model, we developed an optimized CRISPR-associated transposase from cyanobacteria Scytonema hofmanni (ShCAST system), which enables programmable, RNA-guided transposition of ultra-long DNA sequences (30 kb) onto bacterial chromosomes at ∼100% efficiency in a single orientation. In this system, a crRNA (CRISPR RNA) was used to target multicopy loci like insertion-sequence elements or combining I-SceI endonuclease, thereby allowing efficient single-step multiplexed or iterative DNA insertions. The engineered strain exhibited drastically improved substrate diversity and extracellular electron transfer ability, verifying the success of this system. Our work greatly expands the application range and flexibility of genetic engineering techniques and may be readily extended to other bacteria for better controlling various microbial processes.
Collapse
Affiliation(s)
- Zhou-Hua Cheng
- School of Life Sciences, University of Science and Technology of China, Hefei, 230026, China
| | - Jie Wu
- Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Jia-Qi Liu
- Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Di Min
- Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Dong-Feng Liu
- School of Life Sciences, University of Science and Technology of China, Hefei, 230026, China.,Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Wen-Wei Li
- Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Han-Qing Yu
- Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| |
Collapse
|
43
|
Wimmer F, Mougiakos I, Englert F, Beisel CL. Rapid cell-free characterization of multi-subunit CRISPR effectors and transposons. Mol Cell 2022; 82:1210-1224.e6. [PMID: 35216669 DOI: 10.1016/j.molcel.2022.01.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 11/30/2021] [Accepted: 01/26/2022] [Indexed: 11/25/2022]
Abstract
CRISPR-Cas biology and technologies have been largely shaped to date by the characterization and use of single-effector nucleases. By contrast, multi-subunit effectors dominate natural systems, represent emerging technologies, and were recently associated with RNA-guided DNA transposition. This disconnect stems from the challenge of working with multiple protein subunits in vitro and in vivo. Here, we apply cell-free transcription-translation (TXTL) systems to radically accelerate the characterization of multi-subunit CRISPR effectors and transposons. Numerous DNA constructs can be combined in one TXTL reaction, yielding defined biomolecular readouts in hours. Using TXTL, we mined phylogenetically diverse I-E effectors, interrogated extensively self-targeting I-C and I-F systems, and elucidated targeting rules for I-B and I-F CRISPR transposons using only DNA-binding components. We further recapitulated DNA transposition in TXTL, which helped reveal a distinct branch of I-B CRISPR transposons. These capabilities will facilitate the study and exploitation of the broad yet underexplored diversity of CRISPR-Cas systems and transposons.
Collapse
Affiliation(s)
- Franziska Wimmer
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Ioannis Mougiakos
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Frank Englert
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Chase L Beisel
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany; Medical Faculty, University of Würzburg, 97080 Würzburg, Germany.
| |
Collapse
|
44
|
Nambiar TS, Baudrier L, Billon P, Ciccia A. CRISPR-based genome editing through the lens of DNA repair. Mol Cell 2022; 82:348-388. [PMID: 35063100 PMCID: PMC8887926 DOI: 10.1016/j.molcel.2021.12.026] [Citation(s) in RCA: 77] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/18/2021] [Accepted: 12/20/2021] [Indexed: 01/22/2023]
Abstract
Genome editing technologies operate by inducing site-specific DNA perturbations that are resolved by cellular DNA repair pathways. Products of genome editors include DNA breaks generated by CRISPR-associated nucleases, base modifications induced by base editors, DNA flaps created by prime editors, and integration intermediates formed by site-specific recombinases and transposases associated with CRISPR systems. Here, we discuss the cellular processes that repair CRISPR-generated DNA lesions and describe strategies to obtain desirable genomic changes through modulation of DNA repair pathways. Advances in our understanding of the DNA repair circuitry, in conjunction with the rapid development of innovative genome editing technologies, promise to greatly enhance our ability to improve food production, combat environmental pollution, develop cell-based therapies, and cure genetic and infectious diseases.
Collapse
Affiliation(s)
- Tarun S Nambiar
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Lou Baudrier
- Department of Biochemistry and Molecular Biology, Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive N.W., Calgary, Alberta T2N 4N1, Canada
| | - Pierre Billon
- Department of Biochemistry and Molecular Biology, Robson DNA Science Centre, Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive N.W., Calgary, Alberta T2N 4N1, Canada.
| | - Alberto Ciccia
- Department of Genetics and Development, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA.
| |
Collapse
|
45
|
Cargo Genes of Tn 7-Like Transposons Comprise an Enormous Diversity of Defense Systems, Mobile Genetic Elements, and Antibiotic Resistance Genes. mBio 2021; 12:e0293821. [PMID: 34872347 PMCID: PMC8649781 DOI: 10.1128/mbio.02938-21] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Transposition is a major mechanism of horizontal gene mobility in prokaryotes. However, exploration of the genes mobilized by transposons (cargo) is hampered by the difficulty in delineating integrated transposons from their surrounding genetic context. Here, we present a computational approach that allowed us to identify the boundaries of 6,549 Tn7-like transposons. We found that 96% of these transposons carry at least one cargo gene. Delineation of distinct communities in a gene-sharing network demonstrates how transposons function as a conduit of genes between phylogenetically distant hosts. Comparative analysis of the cargo genes reveals significant enrichment of mobile genetic elements (MGEs) nested within Tn7-like transposons, such as insertion sequences and toxin-antitoxin modules, and of genes involved in recombination, anti-MGE defense, and antibiotic resistance. More unexpectedly, cargo also includes genes encoding central carbon metabolism enzymes. Twenty-two Tn7-like transposons carry both an anti-MGE defense system and antibiotic resistance genes, illustrating how bacteria can overcome these combined pressures upon acquisition of a single transposon. This work substantially expands the distribution of Tn7-like transposons, defines their evolutionary relationships, and provides a large-scale functional classification of prokaryotic genes mobilized by transposition.
Collapse
|
46
|
Rybarski JR, Hu K, Hill AM, Wilke CO, Finkelstein IJ. Metagenomic discovery of CRISPR-associated transposons. Proc Natl Acad Sci U S A 2021; 118:e2112279118. [PMID: 34845024 PMCID: PMC8670466 DOI: 10.1073/pnas.2112279118] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 10/26/2021] [Indexed: 12/26/2022] Open
Abstract
CRISPR-associated Tn7 transposons (CASTs) co-opt cas genes for RNA-guided transposition. CASTs are exceedingly rare in genomic databases; recent surveys have reported Tn7-like transposons that co-opt Type I-F, I-B, and V-K CRISPR effectors. Here, we expand the diversity of reported CAST systems via a bioinformatic search of metagenomic databases. We discover architectures for all known CASTs, including arrangements of the Cascade effectors, target homing modalities, and minimal V-K systems. We also describe families of CASTs that have co-opted the Type I-C and Type IV CRISPR-Cas systems. Our search for non-Tn7 CASTs identifies putative candidates that include a nuclease dead Cas12. These systems shed light on how CRISPR systems have coevolved with transposases and expand the programmable gene-editing toolkit.
Collapse
Affiliation(s)
- James R Rybarski
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712
| | - Kuang Hu
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712
| | - Alexis M Hill
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712
| | - Claus O Wilke
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712;
| | - Ilya J Finkelstein
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712;
- Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX 78712
| |
Collapse
|
47
|
Xiao R, Wang S, Han R, Li Z, Gabel C, Mukherjee IA, Chang L. Structural basis of target DNA recognition by CRISPR-Cas12k for RNA-guided DNA transposition. Mol Cell 2021; 81:4457-4466.e5. [PMID: 34450043 PMCID: PMC8571069 DOI: 10.1016/j.molcel.2021.07.043] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 07/15/2021] [Accepted: 07/29/2021] [Indexed: 02/08/2023]
Abstract
The type V-K CRISPR-Cas system, featured by Cas12k effector with a naturally inactivated RuvC domain and associated with Tn7-like transposon for RNA-guided DNA transposition, is a promising tool for precise DNA insertion. To reveal the mechanism underlying target DNA recognition, we determined a cryoelectron microscopy (cryo-EM) structure of Cas12k from cyanobacteria Scytonema hofmanni in complex with a single guide RNA (sgRNA) and a double-stranded target DNA. Coupled with mutagenesis and in vitro DNA transposition assay, our results revealed mechanisms for the recognition of the GGTT protospacer adjacent motif (PAM) sequence and the structural elements of Cas12k critical for RNA-guided DNA transposition. These structural and mechanistic insights should aid in the development of type V-K CRISPR-transposon systems as tools for genome editing.
Collapse
Affiliation(s)
- Renjian Xiao
- Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907, USA
| | - Shukun Wang
- Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907, USA
| | - Ruijie Han
- Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907, USA
| | - Zhuang Li
- Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907, USA
| | - Clinton Gabel
- Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907, USA
| | - Indranil Arun Mukherjee
- Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907, USA
| | - Leifu Chang
- Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907, USA; Purdue University Center for Cancer Research, Purdue University, 915 W. State Street, West Lafayette, IN 47907, USA.
| |
Collapse
|
48
|
Querques I, Schmitz M, Oberli S, Chanez C, Jinek M. Target site selection and remodelling by type V CRISPR-transposon systems. Nature 2021; 599:497-502. [PMID: 34759315 PMCID: PMC7613401 DOI: 10.1038/s41586-021-04030-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 09/16/2021] [Indexed: 11/09/2022]
Abstract
Canonical CRISPR-Cas systems provide adaptive immunity against mobile genetic elements1. However, type I-F, I-B and V-K systems have been adopted by Tn7-like transposons to direct RNA-guided transposon insertion2-7. Type V-K CRISPR-associated transposons rely on the pseudonuclease Cas12k, the transposase TnsB, the AAA+ ATPase TnsC and the zinc-finger protein TniQ7, but the molecular mechanism of RNA-directed DNA transposition has remained elusive. Here we report cryo-electron microscopic structures of a Cas12k-guide RNA-target DNA complex and a DNA-bound, polymeric TnsC filament from the CRISPR-associated transposon system of the photosynthetic cyanobacterium Scytonema hofmanni. The Cas12k complex structure reveals an intricate guide RNA architecture and critical interactions mediating RNA-guided target DNA recognition. TnsC helical filament assembly is ATP-dependent and accompanied by structural remodelling of the bound DNA duplex. In vivo transposition assays corroborate key features of the structures, and biochemical experiments show that TniQ restricts TnsC polymerization, while TnsB interacts directly with TnsC filaments to trigger their disassembly upon ATP hydrolysis. Together, these results suggest that RNA-directed target selection by Cas12k primes TnsC polymerization and DNA remodelling, generating a recruitment platform for TnsB to catalyse site-specific transposon insertion. Insights from this work will inform the development of CRISPR-associated transposons as programmable site-specific gene insertion tools.
Collapse
Affiliation(s)
- Irma Querques
- Department of Biochemistry, University of Zurich, Zurich, 8057, Switzerland
| | - Michael Schmitz
- Department of Biochemistry, University of Zurich, Zurich, 8057, Switzerland
| | - Seraina Oberli
- Department of Biochemistry, University of Zurich, Zurich, 8057, Switzerland
| | - Christelle Chanez
- Department of Biochemistry, University of Zurich, Zurich, 8057, Switzerland
| | - Martin Jinek
- Department of Biochemistry, University of Zurich, Zurich, Switzerland.
| |
Collapse
|