1
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Tang N, Wu Z, Gao Y, Chen W, Wang Z, Su M, Ji W, Ji Q. Molecular Basis and Genome Editing Applications of a Compact Eubacterium ventriosum CRISPR-Cas9 System. ACS Synth Biol 2024; 13:269-281. [PMID: 38061052 DOI: 10.1021/acssynbio.3c00501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
CRISPR-Cas9 systems have been widely harnessed for diverse genome editing applications because of their ease of use and high efficiency. However, the large molecular sizes and strict PAM requirements of commonly used CRISPR-Cas9 systems restrict their broad applications in therapeutics. Here, we report the molecular basis and genome editing applications of a novel compact type II-A Eubacterium ventriosum CRISPR-Cas9 system (EvCas9) with 1107 residues and distinct 5'-NNGDGN-3' (where D represents A, T, or G) PAM specificity. We determine the cryo-EM structure of EvCas9 in a complex with an sgRNA and a target DNA, revealing the detailed PAM recognition and sgRNA and target DNA association mechanisms. Additionally, we demonstrate the robust genome editing capacity of EvCas9 in bacteria and human cells with superior fidelity compared to SaCas9 and SpCas9, and we engineer it to be efficient base editors by fusing a cytidine or adenosine deaminase. Collectively, our results facilitate further understanding of CRISPR-Cas9 working mechanisms and expand the compact CRISPR-Cas9 toolbox.
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Affiliation(s)
- Na Tang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Zhaowei Wu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yan Gao
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Weizhong Chen
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Zixiao Wang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Mengjiao Su
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Wenxin Ji
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Quanjiang Ji
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Gene Editing Center, School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
- Shanghai Clinical Research and Trial Center, Shanghai 201210, China
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2
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Matveeva A, Ryabchenko A, Petrova V, Prokhorova D, Zhuravlev E, Zakabunin A, Tikunov A, Stepanov G. Expression and Functional Analysis of the Compact Thermophilic Anoxybacillus flavithermus Cas9 Nuclease. Int J Mol Sci 2023; 24:17121. [PMID: 38069443 PMCID: PMC10707453 DOI: 10.3390/ijms242317121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 11/30/2023] [Accepted: 12/01/2023] [Indexed: 12/18/2023] Open
Abstract
Research on Cas9 nucleases from different organisms holds great promise for advancing genome engineering and gene therapy tools, as it could provide novel structural insights into CRISPR editing mechanisms, expanding its application area in biology and medicine. The subclass of thermophilic Cas9 nucleases is actively expanding due to the advances in genome sequencing allowing for the meticulous examination of various microorganisms' genomes in search of the novel CRISPR systems. The most prominent thermophilic Cas9 effectors known to date are GeoCas9, ThermoCas9, IgnaviCas9, AceCas9, and others. These nucleases are characterized by a varying temperature range of the activity and stringent PAM preferences; thus, further diversification of the naturally occurring thermophilic Cas9 subclass presents an intriguing task. This study focuses on generating a construct to express a compact Cas9 nuclease (AnoCas9) from the thermophilic microorganism Anoxybacillus flavithermus displaying the nuclease activity in the 37-60 °C range and the PAM preference of 5'-NNNNCDAA-3' in vitro. Here, we highlight the close relation of AnoCas9 to the GeoCas9 family of compact thermophilic Cas9 effectors. AnoCas9, beyond broadening the repertoire of Cas9 nucleases, suggests application in areas requiring the presence of thermostable CRISPR/Cas systems in vitro, such as sequencing libraries' enrichment, allele-specific isothermal PCR, and others.
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Affiliation(s)
| | | | | | | | | | | | | | - Grigory Stepanov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia; (A.M.); (V.P.); (E.Z.); (A.T.)
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3
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Yang Z, Li Z, Li B, Bu R, Tan GY, Wang Z, Yan H, Xin Z, Zhang G, Li M, Xiang H, Zhang L, Wang W. A thermostable type I-B CRISPR-Cas system for orthogonal and multiplexed genetic engineering. Nat Commun 2023; 14:6193. [PMID: 37794017 PMCID: PMC10551041 DOI: 10.1038/s41467-023-41973-5] [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: 04/19/2023] [Accepted: 09/26/2023] [Indexed: 10/06/2023] Open
Abstract
Thermophilic cell factories have remarkably broad potential for industrial applications, but are limited by a lack of genetic manipulation tools and recalcitrance to transformation. Here, we identify a thermophilic type I-B CRISPR-Cas system from Parageobacillus thermoglucosidasius and find it displays highly efficient transcriptional repression or DNA cleavage activity that can be switched by adjusting crRNA length to less than or greater than 26 bp, respectively, without ablating Cas3 nuclease. We then develop an orthogonal tool for genome editing and transcriptional repression using this type I-B system in both thermophile and mesophile hosts. Empowered by this tool, we design a strategy to screen the genome-scale targets involved in transformation efficiency and established dynamically controlled supercompetent P. thermoglucosidasius cells with high efficiency ( ~ 108 CFU/μg DNA) by temporal multiplexed repression. We also demonstrate the construction of thermophilic riboflavin cell factory with hitherto highest titers in high temperature fermentation by genome-scale identification and combinatorial manipulation of multiple targets. This work enables diverse high-efficiency genetic manipulation in P. thermoglucosidasius and facilitates the engineering of thermophilic cell factories.
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Affiliation(s)
- Zhiheng Yang
- State Key Laboratory of Bioreactor Engineering, and School of Biotechnology, East China University of Science and Technology (ECUST), 200237, Shanghai, China
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China
| | - Zilong Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China
| | - Bixiao Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China
| | - Ruihong Bu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China
- School of Medicine and Pharmacy, Ocean University of China, 266003, Qingdao, China
| | - Gao-Yi Tan
- State Key Laboratory of Bioreactor Engineering, and School of Biotechnology, East China University of Science and Technology (ECUST), 200237, Shanghai, China
| | - Zhengduo Wang
- State Key Laboratory of Bioreactor Engineering, and School of Biotechnology, East China University of Science and Technology (ECUST), 200237, Shanghai, China
| | - Hao Yan
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China
| | - Zhenguo Xin
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China
| | - Guojian Zhang
- School of Medicine and Pharmacy, Ocean University of China, 266003, Qingdao, China
| | - Ming Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Hua Xiang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Lixin Zhang
- State Key Laboratory of Bioreactor Engineering, and School of Biotechnology, East China University of Science and Technology (ECUST), 200237, Shanghai, China.
| | - Weishan Wang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China.
- University of Chinese Academy of Sciences, 100049, Beijing, China.
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4
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Das A, Rai J, Roth MO, Shu Y, Medina ML, Barakat MR, Li H. Coupled catalytic states and the role of metal coordination in Cas9. Nat Catal 2023; 6:969-977. [PMID: 38348449 PMCID: PMC10861241 DOI: 10.1038/s41929-023-01031-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 08/29/2023] [Indexed: 02/15/2024]
Abstract
Controlling the activity of the CRISPR-Cas9 system is essential to its safe adoption for clinical and research applications. Although the conformational dynamics of Cas9 are known to control its enzymatic activity, details of how Cas9 influences the catalytic processes at both nuclease domains remain elusive. Here we report five cryo-electron microscopy structures of the active Acidothermus cellulolyticus Cas9 complex along the reaction path at 2.2-2.9 Å resolution. We observed that a large movement in one nuclease domain, triggered by the cognate DNA, results in noticeable changes in the active site of the other domain that is required for metal coordination and catalysis. Furthermore, the conformations synchronize the reaction intermediates, enabling coupled cutting of the two DNA strands. Consistent with the roles of conformations in organizing the active sites, adjustments to the metal-coordination residues lead to altered metal specificity of A. cellulolyticus Cas9 and commonly used Streptococcus pyogenes Cas9 in cells.
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Affiliation(s)
- Anuska Das
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, USA
- These authors contributed equally: Anuska Das, Jay Rai, Mitchell O. Roth
| | - Jay Rai
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, USA
- Present address: Materials and Structural Analysis Division, Thermo Fisher Scientific, Hillsboro, OR, USA
- These authors contributed equally: Anuska Das, Jay Rai, Mitchell O. Roth
| | - Mitchell O. Roth
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, USA
- These authors contributed equally: Anuska Das, Jay Rai, Mitchell O. Roth
| | - Yuerong Shu
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, USA
| | - Megan L. Medina
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, USA
| | - Mackenzie R. Barakat
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, USA
| | - Hong Li
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, USA
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, USA
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5
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Wei N, Shang L, Liu J, Wang M, Liu Y, Zhu C, Fei C, Zhang L, Yang F, Gu F. Engineered Staphylococcus auricularis Cas9 with high-fidelity. FASEB J 2023; 37:e23060. [PMID: 37389931 DOI: 10.1096/fj.202202132rr] [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: 12/22/2022] [Revised: 06/03/2023] [Accepted: 06/13/2023] [Indexed: 07/01/2023]
Abstract
CRISPR-Cas9 is a versatile gene editing tool with a broad application of basic research and clinical therapeutics. However, the potential impact caused by off-target effects remains a critical bottleneck. The small Cas9 ortholog from Staphylococcus auricularis (SauriCas9) was identified, which recognizes a 5'-NNGG-3' protospacer adjacent motif (PAM), exhibiting high activity for genome editing. Recently, we also reported enhanced-fidelity Staphylococcus aureus Cas9 (efSaCas9), which harbors a single mutation N260D. Protein sequence alignment revealed that SauriCas9 has 62.4% sequence identity with SaCas9. Because SauriCas9 is more flexible in recognizing the target sequence with PAM of 5'-NNGG-3' than SaCas9 of 5'-NNGRRT-3' PAM, we sought to test whether key mutation(N260D) or adjacent residue mutation in efSaCas9 can be appliable to SauriCas9. With this concept, two engineered SauriCas9 variants (SauriCas9-HF1, harboring the N269D mutation; SauriCas9-HF2, harboring the D270N mutation) dramatically improved targeting specificity by targeted deep sequencing and GUIDE-seq. At certain sites, reduced off-target effects (approximately 61.6- and 111.9-fold improvements) of SauriCas9-HF2 compared with wild-type SauriCas9 were observed. Overall, two identified SauriCas9 variants (SauriCas9-HF1 and SauriCas9-HF2) expand the utility of the CRISPR toolkit for research and therapeutic applications.
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Affiliation(s)
- Nan Wei
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai, China
| | - Lu Shang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai, China
| | - Jing Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai, China
| | - Mi Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai, China
| | - Yingchun Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai, China
| | - Chuangang Zhu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Chenzhong Fei
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai, China
| | - Lifang Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai, China
| | - Fayu Yang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai, China
| | - Feng Gu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai, China
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6
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Trasanidou D, Barendse P, Bouzetos E, de Haan L, Bouwmeester H, Staals RHJ, Mougiakos I, van der Oost J. Efficient Genome and Base Editing in Human Cells Using ThermoCas9. CRISPR J 2023; 6:278-288. [PMID: 37134217 DOI: 10.1089/crispr.2023.0005] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023] Open
Abstract
Most genetic engineering applications reported thus far rely on the type II-A CRISPR-Cas9 nuclease from Streptococcus pyogenes (SpyCas9), limiting the genome-targeting scope. In this study, we demonstrate that a small, naturally accurate, and thermostable type II-C Cas9 ortholog from Geobacillus thermodenitrificans (ThermoCas9) with alternative target site preference is active in human cells, and it can be used as an efficient genome editing tool, especially for gene disruption. In addition, we develop a ThermoCas9-mediated base editor, called ThermoBE4, for programmable nicking and subsequent C-to-T conversions in human genomes. ThermoBE4 exhibits a three times larger window of activity compared with the corresponding SpyCas9 base editor (BE4), which may be an advantage for gene mutagenesis applications. Hence, ThermoCas9 provides an alternative platform that expands the targeting scope of both genome and base editing in human cells.
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Affiliation(s)
- Despoina Trasanidou
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands
- Laboratory of Toxicology, Wageningen University and Research, Wageningen, The Netherlands
| | - Patrick Barendse
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands
- Laboratory of Toxicology, Wageningen University and Research, Wageningen, The Netherlands
| | - Evgenios Bouzetos
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands
- Laboratory of Toxicology, Wageningen University and Research, Wageningen, The Netherlands
| | - Laura de Haan
- Laboratory of Toxicology, Wageningen University and Research, Wageningen, The Netherlands
| | - Hans Bouwmeester
- Laboratory of Toxicology, Wageningen University and Research, Wageningen, The Netherlands
| | - Raymond H J Staals
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands
| | - Ioannis Mougiakos
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands
- Laboratory of Toxicology, Wageningen University and Research, Wageningen, The Netherlands
| | - John van der Oost
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands
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7
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Hwang S, Maxwell KL. Diverse Mechanisms of CRISPR-Cas9 Inhibition by Type II Anti-CRISPR Proteins. J Mol Biol 2023; 435:168041. [PMID: 36893938 DOI: 10.1016/j.jmb.2023.168041] [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: 12/13/2022] [Revised: 02/25/2023] [Accepted: 03/01/2023] [Indexed: 03/09/2023]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR)-Cas (CRISPR-associated proteins) systems provide bacteria and archaea with an adaptive immune response against invasion by mobile genetic elements like phages, plasmids, and transposons. These systems have been repurposed as very powerful biotechnological tools for gene editing applications in both bacterial and eukaryotic systems. The discovery of natural off-switches for CRISPR-Cas systems, known as anti-CRISPR proteins, provided a mechanism for controlling CRISPR-Cas activity and opened avenues for the development of more precise editing tools. In this review, we focus on the inhibitory mechanisms of anti-CRISPRs that are active against type II CRISPR-Cas systems and briefly discuss their biotechnological applications.
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Affiliation(s)
- Sungwon Hwang
- Department of Biochemistry. University of Toronto, 661 University Avenue, Suite 1600, Toronto, ON M5G 1M1, Canada. https://twitter.com/s1hwang_21
| | - Karen L Maxwell
- Department of Biochemistry. University of Toronto, 661 University Avenue, Suite 1600, Toronto, ON M5G 1M1, Canada.
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8
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Le Y, Sun J. CRISPR/Cas genome editing systems in thermophiles: Current status, associated challenges, and future perspectives. ADVANCES IN APPLIED MICROBIOLOGY 2022; 118:1-30. [PMID: 35461662 DOI: 10.1016/bs.aambs.2022.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Thermophiles, offering an attractive and unique platform for a broad range of applications in biofuels and environment protections, have received a significant attention and growing interest from academy and industry. However, the exploration and exploitation of thermophilic organisms have been hampered by the lack of a powerful genome manipulation tool to improve production efficiency. At current, the clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)/CRISPR associated (Cas) system has been successfully exploited as a competent, simplistic, and powerful tool for genome engineering both in eukaryotes and prokaryotes. Indeed, with the significant efforts made in recent years, some thermostable Cas9 proteins have been well identified and characterized and further, some thermostable Cas9-based editing tools have been successfully established in some representative obligate thermophiles. In this regard, we reviewed the current status and its progress in CRISPR/Cas-based genome editing system towards a variety of thermophilic organisms. Despite the potentials of these progresses, multiple factors/barriers still have to be overcome and optimized for improving its editing efficiency in thermophiles. Some insights into the roles of thermostable CRISPR/Cas technologies for the metabolic engineering of thermophiles as a thermophilic microbial cell factory were also fully analyzed and discussed.
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Affiliation(s)
- Yilin Le
- Biofuels institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu, PR China.
| | - Jianzhong Sun
- Biofuels institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu, PR China.
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9
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Forsberg KJ, Schmidtke DT, Werther R, Uribe RV, Hausman D, Sommer MOA, Stoddard BL, Kaiser BK, Malik HS. The novel anti-CRISPR AcrIIA22 relieves DNA torsion in target plasmids and impairs SpyCas9 activity. PLoS Biol 2021; 19:e3001428. [PMID: 34644300 PMCID: PMC8545432 DOI: 10.1371/journal.pbio.3001428] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 10/25/2021] [Accepted: 09/28/2021] [Indexed: 11/18/2022] Open
Abstract
To overcome CRISPR-Cas defense systems, many phages and mobile genetic elements (MGEs) encode CRISPR-Cas inhibitors called anti-CRISPRs (Acrs). Nearly all characterized Acrs directly bind Cas proteins to inactivate CRISPR immunity. Here, using functional metagenomic selection, we describe AcrIIA22, an unconventional Acr found in hypervariable genomic regions of clostridial bacteria and their prophages from human gut microbiomes. AcrIIA22 does not bind strongly to SpyCas9 but nonetheless potently inhibits its activity against plasmids. To gain insight into its mechanism, we obtained an X-ray crystal structure of AcrIIA22, which revealed homology to PC4-like nucleic acid-binding proteins. Based on mutational analyses and functional assays, we deduced that acrIIA22 encodes a DNA nickase that relieves torsional stress in supercoiled plasmids. This may render them less susceptible to SpyCas9, which uses free energy from negative supercoils to form stable R-loops. Modifying DNA topology may provide an additional route to CRISPR-Cas resistance in phages and MGEs.
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Affiliation(s)
- Kevin J. Forsberg
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- * E-mail:
| | - Danica T. Schmidtke
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Rachel Werther
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Ruben V. Uribe
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Deanna Hausman
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Morten O. A. Sommer
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Barry L. Stoddard
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Brett K. Kaiser
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Department of Biology, Seattle University, Seattle, Washington, United States of America
| | - Harmit S. Malik
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
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10
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Hu Z, Zhang C, Wang S, Gao S, Wei J, Li M, Hou L, Mao H, Wei Y, Qi T, Liu H, Liu D, Lan F, Lu D, Wang H, Li J, Wang Y. Discovery and engineering of small SlugCas9 with broad targeting range and high specificity and activity. Nucleic Acids Res 2021; 49:4008-4019. [PMID: 33721016 PMCID: PMC8053104 DOI: 10.1093/nar/gkab148] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 02/17/2021] [Accepted: 02/23/2021] [Indexed: 02/07/2023] Open
Abstract
The compact CRISPR/Cas9 system, which can be delivered with their gRNA and a full-length promoter for expression by a single adeno-associated virus (AAV), is a promising platform for therapeutic applications. We previously identified a compact SauriCas9 that displays high activity and requires a simple NNGG PAM, but the specificity is moderate. Here, we identified three compact Cas9 orthologs, Staphylococcus lugdunensis Cas9 (SlugCas9), Staphylococcus lutrae Cas9 (SlutrCas9) and Staphylococcus haemolyticus Cas9 (ShaCas9), for mammalian genome editing. Of these three Cas9 orthologs, SlugCas9 recognizes a simple NNGG PAM and displays comparable activity to SaCas9. Importantly, we generated a SlugCas9-SaCas9 chimeric nuclease, which has both high specificity and high activity. We finally engineered SlugCas9 with mutations to generate a high-fidelity variant that maintains high specificity without compromising on-target editing efficiency. Our study offers important minimal Cas9 tools that are ideal for both basic research and clinical applications.
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Affiliation(s)
| | | | - Shuai Wang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200438, China
| | - Siqi Gao
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200438, China
| | - Jingjing Wei
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200438, China
| | - Miaomiao Li
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200438, China
| | - Linghui Hou
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200438, China
| | - Huilin Mao
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200438, China
| | - Yanyan Wei
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200438, China
| | - Tao Qi
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200438, China
| | - Hongmao Liu
- Shanghai Key Laboratory for Assisted Reproduction and Reproductive Genetics, Center for Reproductive Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200135,China
| | - Dong Liu
- School of Life Sciences, Co-innovation Center of Neuroregeneration, Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Feng Lan
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China
| | - Daru Lu
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200438, China
- NHC Key Laboratory of Birth Defects and Reproductive Health, Chongqing Key Laboratory of Birth Defects and Reproductive Health, Chongqing Population and Family Planning, Science and Technology Research Institute, Chongqing, 400020, China
| | - Hongyan Wang
- Correspondence may also be addressed to Hongyan Wang. Tel: +86 21 3124 6611;
| | - Jixi Li
- Correspondence may also be addressed to Jixi Li. Tel: +86 21 3124 6539;
| | - Yongming Wang
- To whom correspondence should be addressed. Tel: +86 21 3124 6624;
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11
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Efficient genome editing of an extreme thermophile, Thermus thermophilus, using a thermostable Cas9 variant. Sci Rep 2021; 11:9586. [PMID: 33953310 PMCID: PMC8100143 DOI: 10.1038/s41598-021-89029-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 04/20/2021] [Indexed: 02/03/2023] Open
Abstract
Thermophilic organisms are extensively studied in industrial biotechnology, for exploration of the limits of life, and in other contexts. Their optimal growth at high temperatures presents a challenge for the development of genetic tools for their genome editing, since genetic markers and selection substrates are often thermolabile. We sought to develop a thermostable CRISPR-Cas9 based system for genome editing of thermophiles. We identified CaldoCas9 and designed an associated guide RNA and showed that the pair have targetable nuclease activity in vitro at temperatures up to 65 °C. We performed a detailed characterization of the protospacer adjacent motif specificity of CaldoCas9, which revealed a preference for 5'-NNNNGNMA. We constructed a plasmid vector for the delivery and use of the CaldoCas9 based genome editing system in the extreme thermophile Thermus thermophilus at 65 °C. Using the vector, we generated gene knock-out mutants of T. thermophilus, targeting genes on the bacterial chromosome and megaplasmid. Mutants were obtained at a frequency of about 90%. We demonstrated that the vector can be cured from mutants for a subsequent round of genome editing. CRISPR-Cas9 based genome editing has not been reported previously in the extreme thermophile T. thermophilus. These results may facilitate development of genome editing tools for other extreme thermophiles and to that end, the vector has been made available via the plasmid repository Addgene.
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12
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Parameshwaran HP, Babu K, Tran C, Guan K, Allen A, Kathiresan V, Qin PZ, Rajan R. The bridge helix of Cas12a imparts selectivity in cis-DNA cleavage and regulates trans-DNA cleavage. FEBS Lett 2021; 595:892-912. [PMID: 33523494 PMCID: PMC8044059 DOI: 10.1002/1873-3468.14051] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 01/15/2021] [Accepted: 01/21/2021] [Indexed: 12/26/2022]
Abstract
Cas12a is an RNA-guided DNA endonuclease of the type V-A CRISPR-Cas system that has evolved convergently with the type II Cas9 protein. We previously showed that proline substitutions in the bridge helix (BH) impart target DNA cleavage selectivity in Streptococcus pyogenes (Spy) Cas9. Here, we examined a BH variant of Cas12a from Francisella novicida (FnoCas12aKD2P ) to test mechanistic conservation. Our results show that for RNA-guided DNA cleavage (cis-activity), FnoCas12aKD2P accumulates nicked products while cleaving supercoiled DNA substrates with mismatches, with certain mismatch positions being more detrimental for linearization. FnoCas12aKD2P also possess reduced trans-single-stranded DNA cleavage activity. These results implicate the BH in substrate selectivity in both cis- and trans-cleavages and show its conserved role in target discrimination among Cas nucleases.
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Affiliation(s)
- Hari Priya Parameshwaran
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, University of Oklahoma, Stephenson Life Sciences Research Center, Norman, OK, USA
| | - Kesavan Babu
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, University of Oklahoma, Stephenson Life Sciences Research Center, Norman, OK, USA
| | - Christine Tran
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, University of Oklahoma, Stephenson Life Sciences Research Center, Norman, OK, USA
| | - Kevin Guan
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, University of Oklahoma, Stephenson Life Sciences Research Center, Norman, OK, USA
| | - Aleique Allen
- Department of Chemistry, University of Southern California, Los Angeles, CA, USA
| | | | - Peter Z Qin
- Department of Chemistry, University of Southern California, Los Angeles, CA, USA
| | - Rakhi Rajan
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, University of Oklahoma, Stephenson Life Sciences Research Center, Norman, OK, USA
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13
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Hand TH, Roth MO, Smith CL, Shiel E, Klein KN, Gilbert DM, Li H. Catalytically Enhanced Cas9 through Directed Protein Evolution. CRISPR J 2021; 4:223-232. [PMID: 33876948 PMCID: PMC8182482 DOI: 10.1089/crispr.2020.0092] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Guided by the extensive knowledge of CRISPR-Cas9 molecular mechanisms, protein engineering can be an effective method in improving CRISPR-Cas9 toward desired traits different from those of their natural forms. Here, we describe a directed protein evolution method that enables selection of catalytically enhanced CRISPR-Cas9 variants (CECas9) by targeting a shortened protospacer within a toxic gene. We demonstrate the effectiveness of this method with a previously characterized Type II-C Cas9 from Acidothermus cellulolyticus (AceCas9) and show by enzyme kinetics an up to fourfold improvement of the in vitro catalytic efficiency by AceCECas9. We further evolved the more widely used Streptococcus pyogenes Cas9 (SpyCas9) and demonstrated a noticeable improvement in the SpyCECas9-facilitated homology directed repair-based gene insertion in human colon cancer cells.
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Affiliation(s)
- Travis H. Hand
- Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida, USA; Florida State University, Tallahassee, Florida, USA
| | - Mitchell O. Roth
- Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida, USA; Florida State University, Tallahassee, Florida, USA
| | - Chardasia L. Smith
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida, USA; and Florida State University, Tallahassee, Florida, USA
| | - Emily Shiel
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida, USA; and Florida State University, Tallahassee, Florida, USA
| | - Kyle N. Klein
- Department of Biological Sciences, Florida State University, Tallahassee, Florida, USA
| | - David M. Gilbert
- Department of Biological Sciences, Florida State University, Tallahassee, Florida, USA
| | - Hong Li
- Institute of Molecular Biophysics, Florida State University, Tallahassee, Florida, USA; Florida State University, Tallahassee, Florida, USA
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida, USA; and Florida State University, Tallahassee, Florida, USA
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14
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Collias D, Beisel CL. CRISPR technologies and the search for the PAM-free nuclease. Nat Commun 2021; 12:555. [PMID: 33483498 PMCID: PMC7822910 DOI: 10.1038/s41467-020-20633-y] [Citation(s) in RCA: 132] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 12/03/2020] [Indexed: 12/20/2022] Open
Abstract
The ever-expanding set of CRISPR technologies and their programmable RNA-guided nucleases exhibit remarkable flexibility in DNA targeting. However, this flexibility comes with an ever-present constraint: the requirement for a protospacer adjacent motif (PAM) flanking each target. While PAMs play an essential role in self/nonself discrimination by CRISPR-Cas immune systems, this constraint has launched a far-reaching expedition for nucleases with relaxed PAM requirements. Here, we review ongoing efforts toward realizing PAM-free nucleases through natural ortholog mining and protein engineering. We also address potential consequences of fully eliminating PAM recognition and instead propose an alternative nuclease repertoire covering all possible PAM sequences.
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Affiliation(s)
- Daphne Collias
- Department of Chemical & Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
| | - Chase L Beisel
- Department of Chemical & Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA.
- 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.
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15
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Genome Editing of the Anaerobic Thermophile Thermoanaerobacter ethanolicus Using Thermostable Cas9. Appl Environ Microbiol 2020; 87:AEM.01773-20. [PMID: 33067194 DOI: 10.1128/aem.01773-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 10/04/2020] [Indexed: 12/11/2022] Open
Abstract
Thermoanaerobacter ethanolicus can produce acetate, lactate, hydrogen, and ethanol from sugars resulting from plant carbohydrate polymer degradation at temperatures above 65°C. T. ethanolicus is a promising candidate for thermophilic ethanol fermentations due to the utilization of both pentose and hexose. Although an ethanol balance model in T. ethanolicus has been developed, only a few physiological or biochemical experiments regarding the function of important enzymes in ethanol formation have been carried out. To address this issue, we developed a thermostable Cas9-based system for genome editing of T. ethanolicus As a proof of principle, three genes, including the thymidine kinase gene (tdk), acetaldehyde-alcohol dehydrogenase gene (adhE), and redox sensing protein gene (rsp), were chosen as editing targets, and these genes were edited successfully. As a genetic tool, we tested the gene knockout and a small DNA fragment knock-in. After optimization of the transformation strategies, 77% genome-editing efficiency was observed. Furthermore, our in vivo results revealed that redox sensing protein (RSP) plays a more important role in regulation of energy metabolism, including hydrogen production and ethanol formation. The genetic system provides us with an effective strategy to identify genes involved in biosynthesis and energy metabolism.IMPORTANCE Interest in thermophilic microorganisms as emerging metabolic engineering platforms to produce biofuels and chemicals has surged. Thermophilic microbes for biofuels have attracted great attention, due to their tolerance of high temperature and wide range of substrate utilization. On the basis of the biochemical experiments of previous investigation, the formation of ethanol was controlled via transcriptional regulation and influenced by the relevant properties of specific enzymes in T. ethanolicus Thus, there is an urgent need to understand the physiological function of these key enzymes, which requires genetic manipulations such as deletion or overexpression of genes encoding putative key enzymes. Here, we developed a thermostable Cas9-based engineering tool for gene editing in T. ethanolicus The thermostable Cas9-based genome-editing tool may further be applied to metabolically engineer T. ethanolicus to produce biofuels. This genetic system represents an important expansion of the genetic tool box of anaerobic thermophile T. ethanolicus strains.
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16
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Das A, Hand TH, Smith CL, Wickline E, Zawrotny M, Li H. The molecular basis for recognition of 5'-NNNCC-3' PAM and its methylation state by Acidothermus cellulolyticus Cas9. Nat Commun 2020; 11:6346. [PMID: 33311465 PMCID: PMC7733487 DOI: 10.1038/s41467-020-20204-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 11/18/2020] [Indexed: 12/13/2022] Open
Abstract
Acidothermus cellulolyticus CRISPR-Cas9 (AceCas9) is a thermophilic Type II-C enzyme that has potential genome editing applications in extreme environments. It cleaves DNA with a 5'-NNNCC-3' Protospacer Adjacent Motif (PAM) and is sensitive to its methylation status. To understand the molecular basis for the high specificity of AceCas9 for its PAM, we determined two crystal structures of AceCas9 lacking its HNH domain (AceCas9-ΔHNH) bound with a single guide RNA and DNA substrates, one with the correct and the other with an incorrect PAM. Three residues, Glu1044, Arg1088, Arg1091, form an intricate hydrogen bond network with the first cytosine and the two opposing guanine nucleotides to confer specificity. Methylation of the first but not the second cytosine base abolishes AceCas9 activity, consistent with the observed PAM recognition pattern. The high sensitivity of AceCas9 to the modified cytosine makes it a potential device for detecting epigenomic changes in genomes.
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Affiliation(s)
- Anuska Das
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306, USA
| | - Travis H Hand
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306, USA
| | - Chardasia L Smith
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306, USA
| | - Ethan Wickline
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, 32306, USA
| | - Michael Zawrotny
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306, USA
| | - Hong Li
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL, 32306, USA.
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL, 32306, USA.
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17
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Walker JE, Lanahan AA, Zheng T, Toruno C, Lynd LR, Cameron JC, Olson DG, Eckert CA. Development of both type I-B and type II CRISPR/Cas genome editing systems in the cellulolytic bacterium Clostridium thermocellum. Metab Eng Commun 2020; 10:e00116. [PMID: 31890588 PMCID: PMC6926293 DOI: 10.1016/j.mec.2019.e00116] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 11/13/2019] [Accepted: 11/25/2019] [Indexed: 12/21/2022] Open
Abstract
The robust lignocellulose-solubilizing activity of C. thermocellum makes it a top candidate for consolidated bioprocessing for biofuel production. Genetic techniques for C. thermocellum have lagged behind model organisms thus limiting attempts to improve biofuel production. To improve our ability to engineer C. thermocellum, we characterized a native Type I-B and heterologous Type II Clustered Regularly-Interspaced Short Palindromic Repeat (CRISPR)/cas (CRISPR associated) systems. We repurposed the native Type I-B system for genome editing. We tested three thermophilic Cas9 variants (Type II) and found that GeoCas9, isolated from Geobacillus stearothermophilus, is active in C. thermocellum. We employed CRISPR-mediated homology directed repair to introduce a nonsense mutation into pyrF. For both editing systems, homologous recombination between the repair template and the genome appeared to be the limiting step. To overcome this limitation, we tested three novel thermophilic recombinases and demonstrated that exo/beta homologs, isolated from Acidithiobacillus caldus, are functional in C. thermocellum. For the Type I-B system an engineered strain, termed LL1586, yielded 40% genome editing efficiency at the pyrF locus and when recombineering machinery was expressed this increased to 71%. For the Type II GeoCas9 system, 12.5% genome editing efficiency was observed and when recombineering machinery was expressed, this increased to 94%. By combining the thermophilic CRISPR system (either Type I-B or Type II) with the recombinases, we developed a new tool that allows for efficient CRISPR editing. We are now poised to enable CRISPR technologies to better engineer C. thermocellum for both increased lignocellulose degradation and biofuel production.
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Key Words
- 5-FOA, 5-fluoroorotic acid
- CFU, colony forming unit
- CRISPR
- CRISPR/Cas, Clustered Regularly-Interspaced Short Palindromic Repeat/CRISPR associated
- Cas9
- Cas9n, nickase Cas9
- Clostridium thermocellum
- HDR, homology-directed repair
- HR, homologous recombination
- PAM, protospacer adjacent motif
- RNP, Cas9-sgRNA ribonucleoprotein
- Thermophilic recombineering
- Tm, thiamphenicol
- Type I–B
- sgRNA, single guide RNA
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Affiliation(s)
- Julie E. Walker
- Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO, 80303, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Anthony A. Lanahan
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
- Thayer School of Engineering, Dartmouth College, Hanover, NH, 03755, USA
| | - Tianyong Zheng
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
- Thayer School of Engineering, Dartmouth College, Hanover, NH, 03755, USA
| | - Camilo Toruno
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
- Thayer School of Engineering, Dartmouth College, Hanover, NH, 03755, USA
| | - Lee R. Lynd
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
- Thayer School of Engineering, Dartmouth College, Hanover, NH, 03755, USA
| | - Jeffrey C. Cameron
- Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO, 80303, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
- Department of Biochemistry, University of Colorado, Boulder, CO, 80303, USA
- National Renewable Energy Laboratory, Biosciences Center, Golden, USA
| | - Daniel G. Olson
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
- Thayer School of Engineering, Dartmouth College, Hanover, NH, 03755, USA
| | - Carrie A. Eckert
- Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO, 80303, USA
- Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
- National Renewable Energy Laboratory, Biosciences Center, Golden, USA
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18
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Hu Z, Wang S, Zhang C, Gao N, Li M, Wang D, Wang D, Liu D, Liu H, Ong SG, Wang H, Wang Y. A compact Cas9 ortholog from Staphylococcus Auricularis (SauriCas9) expands the DNA targeting scope. PLoS Biol 2020; 18:e3000686. [PMID: 32226015 PMCID: PMC7145270 DOI: 10.1371/journal.pbio.3000686] [Citation(s) in RCA: 92] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 04/09/2020] [Accepted: 03/12/2020] [Indexed: 11/19/2022] Open
Abstract
Compact CRISPR/Cas9 systems that can be packaged into an adeno-associated virus (AAV) hold great promise for gene therapy. Unfortunately, currently available small Cas9 nucleases either display low activity or require a long protospacer adjacent motif (PAM) sequence, limiting their extensive applications. Here, we screened a panel of Cas9 nucleases and identified a small Cas9 ortholog from Staphylococcus auricularis (SauriCas9), which recognizes a simple NNGG PAM, displays high activity for genome editing, and is compact enough to be packaged into an AAV for genome editing. Moreover, the conversion of adenine and cytosine bases can be achieved by fusing SauriCas9 to the cytidine and adenine deaminase. Therefore, SauriCas9 holds great potential for both basic research and clinical applications.
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Affiliation(s)
- Ziying Hu
- Obstetrics and Gynecology Hospital, State Key Laboratory of Genetic Engineering at School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Shuai Wang
- Obstetrics and Gynecology Hospital, State Key Laboratory of Genetic Engineering at School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Chengdong Zhang
- Obstetrics and Gynecology Hospital, State Key Laboratory of Genetic Engineering at School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Ning Gao
- Obstetrics and Gynecology Hospital, State Key Laboratory of Genetic Engineering at School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Miaomiao Li
- Obstetrics and Gynecology Hospital, State Key Laboratory of Genetic Engineering at School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Deqian Wang
- Obstetrics and Gynecology Hospital, State Key Laboratory of Genetic Engineering at School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Daqi Wang
- Obstetrics and Gynecology Hospital, State Key Laboratory of Genetic Engineering at School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Dong Liu
- School of Life Sciences, Co-innovation Center of Neuroregeneration, Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong, China
| | - Huihui Liu
- Experimental Center of Forestry in North China, Chinese Academy of Forestry, Beijing, China
| | - Sang-Ging Ong
- Department of Pharmacology, University of Illinois College of Medicine, Chicago, Illinois, United States of America
- Division of Cardiology, Department of Medicine, University of Illinois College of Medicine, Chicago, Illinois, United States of America
| | - Hongyan Wang
- Obstetrics and Gynecology Hospital, State Key Laboratory of Genetic Engineering at School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yongming Wang
- Obstetrics and Gynecology Hospital, State Key Laboratory of Genetic Engineering at School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China
- School of Life Sciences, Co-innovation Center of Neuroregeneration, Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong, China
- Shanghai Engineering Research Center of Industrial Microorganisms, Shanghai, China
- * E-mail:
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19
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Abstract
Though making up nearly half of the known CRISPR-Cas9 family of enzymes, the Type II-C CRISPR-Cas9 has been underexplored for their molecular mechanisms and potential in safe gene editing applications. In comparison with the more popular Type II-A CRISPR-Cas9, the Type II-C enzymes are generally smaller in size and utilize longer base pairing in identification of their DNA substrates. These characteristics suggest easier portability and potentially less off-targets for Type II-C in gene editing applications. We describe identification and biochemical characterization of a thermophilic Type II-C CRISPR-Cas from Acidothermus cellulolyticus (AceCas9). We describe several library-based methods that enabled us to identify the PAM sequence and elements critical to protospacer mismatch surveillance of AceCas9.
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20
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Hand TH, Das A, Roth MO, Smith CL, Jean-Baptiste UL, Li H. Phosphate Lock Residues of Acidothermus cellulolyticus Cas9 Are Critical to Its Substrate Specificity. ACS Synth Biol 2018; 7:2908-2917. [PMID: 30458109 PMCID: PMC6525624 DOI: 10.1021/acssynbio.8b00455] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Despite being utilized widely in genome sciences, CRISPR-Cas9 remains limited in achieving high fidelity in cleaving DNA. A better understanding of the molecular basis of Cas9 holds the key to improve Cas9-based tools. We employed direct evolution and in vitro characterizations to explore structural parameters that impact the specificity of the thermophilic Cas9 from Acidothermus cellulolyticus (AceCas9). By identifying variants that are able to cleave mismatched protospacers within the seed region, we found a critical role of the phosphate lock residues in substrate specificity in a manner that depends on their sizes and charges. Removal of the negative charge from the phosphate lock residues significantly decreases sensitivity to the guide-DNA mismatches. An increase in size of the substituted residues further reduces the sensitivity to mismatches at the first position of the protospacer. Our findings identify the phosphate lock residues as an important site for tuning the specificity and catalytic efficiency of Cas9.
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Affiliation(s)
- Travis H. Hand
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
| | - Anuska Das
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
| | - Mitchell O. Roth
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
| | - Chardasia L. Smith
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA
| | - Uriel L. Jean-Baptiste
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA
| | - Hong Li
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA
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21
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A CRISPR-Cas9-triggered strand displacement amplification method for ultrasensitive DNA detection. Nat Commun 2018; 9:5012. [PMID: 30479331 PMCID: PMC6258682 DOI: 10.1038/s41467-018-07324-5] [Citation(s) in RCA: 209] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 10/09/2018] [Indexed: 12/26/2022] Open
Abstract
Although polymerase chain reaction (PCR) is the most widely used method for DNA amplification, the requirement of thermocycling limits its non-laboratory applications. Isothermal DNA amplification techniques are hence valuable for on-site diagnostic applications in place of traditional PCR. Here we describe a true isothermal approach for amplifying and detecting double-stranded DNA based on a CRISPR–Cas9-triggered nicking endonuclease-mediated Strand Displacement Amplification method (namely CRISDA). CRISDA takes advantage of the high sensitivity/specificity and unique conformational rearrangements of CRISPR effectors in recognizing the target DNA. In combination with a peptide nucleic acid (PNA) invasion-mediated endpoint measurement, the method exhibits attomolar sensitivity and single-nucleotide specificity in detection of various DNA targets under a complex sample background. Additionally, by integrating the technique with a Cas9-mediated target enrichment approach, CRISDA exhibits sub-attomolar sensitivity. In summary, CRISDA is a powerful isothermal tool for ultrasensitive and specific detection of nucleic acids in point-of-care diagnostics and field analyses. Isothermal DNA amplification techniques are useful for diagnostic applications in place of traditional PCR. Here the authors describe CRISDA, which combines CRISPR–Cas9 with strand displacement amplification and exhibits attomolar sensitivity and single-nucleotide specificity in DNA detection.
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22
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Freed E, Fenster J, Smolinski SL, Walker J, Henard CA, Gill R, Eckert CA. Building a genome engineering toolbox in nonmodel prokaryotic microbes. Biotechnol Bioeng 2018; 115:2120-2138. [PMID: 29750332 DOI: 10.1002/bit.26727] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 04/02/2018] [Accepted: 03/10/2018] [Indexed: 12/26/2022]
Abstract
The realization of a sustainable bioeconomy requires our ability to understand and engineer complex design principles for the development of platform organisms capable of efficient conversion of cheap and sustainable feedstocks (e.g., sunlight, CO2 , and nonfood biomass) into biofuels and bioproducts at sufficient titers and costs. For model microbes, such as Escherichia coli, advances in DNA reading and writing technologies are driving the adoption of new paradigms for engineering biological systems. Unfortunately, microbes with properties of interest for the utilization of cheap and renewable feedstocks, such as photosynthesis, autotrophic growth, and cellulose degradation, have very few, if any, genetic tools for metabolic engineering. Therefore, it is important to develop "design rules" for building a genetic toolbox for novel microbes. Here, we present an overview of our current understanding of these rules for the genetic manipulation of prokaryotic microbes and the available genetic tools to expand our ability to genetically engineer nonmodel systems.
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Affiliation(s)
- Emily Freed
- National Renewable Energy Laboratory, Biosciences Center, Golden, CO.,Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO
| | - Jacob Fenster
- Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO.,Chemical and Biological Engineering, University of Colorado, Boulder, CO
| | | | - Julie Walker
- Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO
| | - Calvin A Henard
- National Renewable Energy Laboratory, National Bioenergy Center, Golden, CO
| | - Ryan Gill
- National Renewable Energy Laboratory, Biosciences Center, Golden, CO.,Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO.,Chemical and Biological Engineering, University of Colorado, Boulder, CO
| | - Carrie A Eckert
- National Renewable Energy Laboratory, Biosciences Center, Golden, CO.,Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO
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23
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Abstract
Genome editing technologies have been revolutionized by the discovery of prokaryotic RNA-guided defense system called CRISPR-Cas. Cas9, a single effector protein found in type II CRISPR systems, has been at the heart of this genome editing revolution. Nearly half of the Cas9s discovered so far belong to the type II-C subtype but have not been explored extensively. Type II-C CRISPR-Cas systems are the simplest of the type II systems, employing only three Cas proteins. Cas9s are central players in type II-C systems since they function in multiple steps of the CRISPR pathway, including adaptation and interference. Type II-C CRISPR systems are found in bacteria and archaea from very diverse environments, resulting in Cas9s with unique and potentially useful properties. Certain type II-C Cas9s possess unusually long PAMs, function in unique conditions (e.g., elevated temperature), and tend to be smaller in size. Here, we review the biology, mechanism, and applications of the type II-C CRISPR systems with particular emphasis on their Cas9s.
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Affiliation(s)
- Aamir Mir
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, U.S.A
| | - Alireza Edraki
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, U.S.A
| | - Jooyoung Lee
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, U.S.A
| | - Erik J. Sontheimer
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, U.S.A
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, U.S.A
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