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Madugula SS, Pujar P, Nammi B, Wang S, Jayasinghe-Arachchige VM, Pham T, Mashburn D, Artiles M, Liu J. Identification of Family-Specific Features in Cas9 and Cas12 Proteins: A Machine Learning Approach Using Complete Protein Feature Spectrum. J Chem Inf Model 2024; 64:4897-4911. [PMID: 38838358 DOI: 10.1021/acs.jcim.4c00625] [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: 06/07/2024]
Abstract
The recent development of CRISPR-Cas technology holds promise to correct gene-level defects for genetic diseases. The key element of the CRISPR-Cas system is the Cas protein, a nuclease that can edit the gene of interest assisted by guide RNA. However, these Cas proteins suffer from inherent limitations such as large size, low cleavage efficiency, and off-target effects, hindering their widespread application as a gene editing tool. Therefore, there is a need to identify novel Cas proteins with improved editing properties, for which it is necessary to understand the underlying features governing the Cas families. In this study, we aim to elucidate the unique protein features associated with Cas9 and Cas12 families and identify the features distinguishing each family from non-Cas proteins. Here, we built Random Forest (RF) binary classifiers to distinguish Cas12 and Cas9 proteins from non-Cas proteins, respectively, using the complete protein feature spectrum (13,494 features) encoding various physiochemical, topological, constitutional, and coevolutionary information on Cas proteins. Furthermore, we built multiclass RF classifiers differentiating Cas9, Cas12, and non-Cas proteins. All the models were evaluated rigorously on the test and independent data sets. The Cas12 and Cas9 binary models achieved a high overall accuracy of 92% and 95% on their respective independent data sets, while the multiclass classifier achieved an F1 score of close to 0.98. We observed that Quasi-Sequence-Order (QSO) descriptors like Schneider.lag and Composition descriptors like charge, volume, and polarizability are predominant in the Cas12 family. Conversely Amino Acid Composition descriptors, especially Tripeptide Composition (TPC), predominate the Cas9 family. Four of the top 10 descriptors identified in Cas9 classification are tripeptides PWN, PYY, HHA, and DHI, which are seen to be conserved across all Cas9 proteins and located within different catalytically important domains of the Streptococcus pyogenes Cas9 (SpCas9) structure. Among these, DHI and HHA are well-known to be involved in the DNA cleavage activity of the SpCas9 protein. Mutation studies have highlighted the significance of the PWN tripeptide in PAM recognition and DNA cleavage activity of SpCas9, while Y450 from the PYY tripeptide plays a crucial role in reducing off-target effects and improving the specificity in SpCas9. Leveraging our machine learning (ML) pipeline, we identified numerous Cas9 and Cas12 family-specific features. These features offer valuable insights for future experimental and computational studies aiming at designing Cas systems with enhanced gene-editing properties. These features suggest plausible structural modifications that can effectively guide the development of Cas proteins with improved editing capabilities.
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Affiliation(s)
- Sita Sirisha Madugula
- Department of Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, Texas 76107, United States
| | - Pranav Pujar
- Department of Industrial, Manufacturing and Systems Engineering, University of Texas at Arlington, 701 South Nedderman Drive, Arlington, Texas 76019, United States
| | - Bharani Nammi
- Department of Industrial, Manufacturing and Systems Engineering, University of Texas at Arlington, 701 South Nedderman Drive, Arlington, Texas 76019, United States
| | - Shouyi Wang
- Department of Industrial, Manufacturing and Systems Engineering, University of Texas at Arlington, 701 South Nedderman Drive, Arlington, Texas 76019, United States
| | - Vindi M Jayasinghe-Arachchige
- Department of Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, Texas 76107, United States
| | - Tyler Pham
- School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, Texas 76107, United States
| | - Dominic Mashburn
- Department of Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, Texas 76107, United States
| | - Maria Artiles
- School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, Texas 76107, United States
| | - Jin Liu
- Department of Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, Texas 76107, United States
- School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, Texas 76107, United States
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2
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Patel A, Sinha S, Arantes P, Palermo G. Unveiling Cas8 Dynamics and Regulation within a transposon-encoded Cascade-TniQ Complex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.21.600075. [PMID: 38948825 PMCID: PMC11213026 DOI: 10.1101/2024.06.21.600075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Cascade is a class 1, type 1 CRISPR-Cas system with a variety of roles in prokaryote defense, specifically against DNA-based viruses. The Vibrio Cholerae transposon, Tn6677, encodes a variant of the type 1F Cascade known as type 1F-3. This Cascade variant complexes with a homodimer of the transposition protein TniQ and leverages the sequence specificity of Cascade to direct the integration activity of the heteromeric transposase tnsA/B, resulting in site-specific transposition of Tn6677. We desire to uncover the molecular details behind R Loop formation of 'Cascade-TniQ.' Due to the lack of a complete model of Cascade-TniQ available at atom-level resolution, we first build a complete model using AlphaFold V2.1. We then simulate this model via classical molecular dynamics and umbrella sampling to study an important regulatory component within Cascade-TniQ, known as the Cas8 'bundle.' Particularly, we show that this alpha helical bundle experiences a free energy barrier to its large-scale translatory motions and relative free energies of its states primarily dependent on a loop within a Cas7 subunit in Cascade-TniQ. Further, we comment on additional structural and dynamical regulatory points of Cascade-TniQ during R Loop formation, such as Cascade-TniQ backbone rigidity, and the potential role TniQ plays in regulating bundle dynamics. In summary, our outcomes provide the first all-atom dynamic representation of one of the largest CRISPR systems, with information that can contribute to understanding the mechanism of nucleic acid binding and, eventually, to transposase recruitment itself. Such information may prove informative to advance genome engineering efforts.
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3
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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.
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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.
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4
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Bhattacharya S, Satpati P. Why Does the E1219V Mutation Expand T-Rich PAM Recognition in Cas9 from Streptococcus pyogenes? J Chem Inf Model 2024; 64:3237-3247. [PMID: 38600752 DOI: 10.1021/acs.jcim.3c01515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
Popular RNA-guided DNA endonuclease Cas9 from Streptococcus pyogenes (SpCas9) recognizes the canonical 5'-NGG-3' protospacer adjacent motif (PAM) and triggers double-stranded DNA cleavage activity. Mutations in SpCas9 were demonstrated to expand the PAM readability and hold promise for therapeutic and genome editing applications. However, the energetics of the PAM recognition and its relation to the atomic structure remain unknown. Using the X-ray structure (precatalytic SpCas9:sgRNA:dsDNA) as a template, we calculated the change in the PAM binding affinity in response to SpCas9 mutations using computer simulations. The E1219V mutation in SpCas9 fine-tunes the water accessibility in the PAM binding pocket and promotes new interactions in the SpCas9:noncanonical T-rich PAM, thus weakening the PAM stringency. The nucleotide-specific interaction of two arginine residues (i.e., R1333 and R1335 of SpCas9) ensured stringent 5'-NGG-3' PAM recognition. R1335A substitution (SpCas9R1335A) completely disrupts the direct interaction between SpCas9 and PAM sequences (canonical or noncanonical), accounting for the loss of editing activity. Interestingly, the double mutant (SpCas9R1335A,E1219V) boosts DNA binding affinity by favoring protein:PAM electrostatic contact in a desolvated pocket. The underlying thermodynamics explain the varied DNA cleavage activity of SpCas9 variants. A direct link between the energetics, structures, and activity is highlighted, which can aid in the rational design of improved SpCas9-based genome editing tools.
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Affiliation(s)
- Shreya Bhattacharya
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Priyadarshi Satpati
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
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5
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Schwartz EA, Bravo JPK, Ahsan M, Macias LA, McCafferty CL, Dangerfield TL, Walker JN, Brodbelt JS, Palermo G, Fineran PC, Fagerlund RD, Taylor DW. RNA targeting and cleavage by the type III-Dv CRISPR effector complex. Nat Commun 2024; 15:3324. [PMID: 38637512 PMCID: PMC11026444 DOI: 10.1038/s41467-024-47506-y] [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: 08/21/2023] [Accepted: 04/02/2024] [Indexed: 04/20/2024] Open
Abstract
CRISPR-Cas are adaptive immune systems in bacteria and archaea that utilize CRISPR RNA-guided surveillance complexes to target complementary RNA or DNA for destruction1-5. Target RNA cleavage at regular intervals is characteristic of type III effector complexes6-8. Here, we determine the structures of the Synechocystis type III-Dv complex, an apparent evolutionary intermediate from multi-protein to single-protein type III effectors9,10, in pre- and post-cleavage states. The structures show how multi-subunit fusion proteins in the effector are tethered together in an unusual arrangement to assemble into an active and programmable RNA endonuclease and how the effector utilizes a distinct mechanism for target RNA seeding from other type III effectors. Using structural, biochemical, and quantum/classical molecular dynamics simulation, we study the structure and dynamics of the three catalytic sites, where a 2'-OH of the ribose on the target RNA acts as a nucleophile for in line self-cleavage of the upstream scissile phosphate. Strikingly, the arrangement at the catalytic residues of most type III complexes resembles the active site of ribozymes, including the hammerhead, pistol, and Varkud satellite ribozymes. Our work provides detailed molecular insight into the mechanisms of RNA targeting and cleavage by an important intermediate in the evolution of type III effector complexes.
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Affiliation(s)
- Evan A Schwartz
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX, USA
| | - Jack P K Bravo
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | - Mohd Ahsan
- Department of Bioengineering and Department of Chemistry, University of California, Riverside, CA, USA
| | - Luis A Macias
- Department of Chemistry, University of Texas at Austin, Austin, TX, USA
| | - Caitlyn L McCafferty
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX, USA
| | - Tyler L Dangerfield
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | - Jada N Walker
- Department of Chemistry, University of Texas at Austin, Austin, TX, USA
| | | | - Giulia Palermo
- Department of Bioengineering and Department of Chemistry, University of California, Riverside, CA, USA.
| | - Peter C Fineran
- Microbiology and Immunology, University of Otago, PO Box 56, Dunedin, New Zealand
- Bioprotection Aotearoa, University of Otago, PO Box 56, Dunedin, New Zealand
- Genetics Otago, University of Otago, PO Box 56, Dunedin, New Zealand
| | - Robert D Fagerlund
- Microbiology and Immunology, University of Otago, PO Box 56, Dunedin, New Zealand.
- Bioprotection Aotearoa, University of Otago, PO Box 56, Dunedin, New Zealand.
- Genetics Otago, University of Otago, PO Box 56, Dunedin, New Zealand.
| | - David W Taylor
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX, USA.
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA.
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX, USA.
- LIVESTRONG Cancer Institutes, Dell Medical School, University of Texas at Austin, Austin, TX, USA.
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Kaur R, Frederickson A, Wetmore SD. Elucidation of the catalytic mechanism of a single-metal dependent homing endonuclease using QM and QM/MM approaches: the case study of I- PpoI. Phys Chem Chem Phys 2024; 26:8919-8931. [PMID: 38426850 DOI: 10.1039/d3cp06201e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
Homing endonucleases (HEs) are highly specific DNA cleaving enzymes, with I-PpoI having been suggested to use a single metal to accelerate phosphodiester bond cleavage. Although an I-PpoI mechanism has been proposed based on experimental structural data, no consensus has been reached regarding the roles of the metal or key active site amino acids. This study uses QM cluster and QM/MM calculations to provide atomic-level details of the I-PpoI catalytic mechanism. Minimal QM cluster and large-scale QM/MM models demonstrate that the experimentally-proposed pathway involving direct Mg2+ coordination to the substrate coupled with leaving group protonation through a metal-activated water is not feasible due to an inconducive I-PpoI active site alignment. Despite QM cluster models of varying size uncovering a pathway involving leaving group protonation by a metal-activated water, indirect (water-mediated) metal coordination to the substrate is required to afford this pathway, which renders this mechanism energetically infeasible. Instead, QM cluster models reveal that the preferred pathway involves direct Mg2+-O3' coordination to stabilize the charged substrate and assist leaving group departure, while H98 activates the water nucleophile. These calculations also underscore that both catalytic residues that directly interact with the substrate and secondary amino acids that position or stabilize these residues are required for efficient catalysis. QM/MM calculations on the solvated enzyme-DNA complex verify the preferred mechanism, which is fully consistent with experimental kinetic, structural, and mutational data. The fundamental understanding of the I-PpoI mechanism of action, gained from the present work can be used to further explore potential uses of this enzyme in biotechnology and medicine, and direct future computational investigations of other members of the understudied HE family.
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Affiliation(s)
- Rajwinder Kaur
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4, Canada.
| | - Angela Frederickson
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4, Canada.
| | - Stacey D Wetmore
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4, Canada.
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7
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Saha A, Ahsan M, Arantes PR, Schmitz M, Chanez C, Jinek M, Palermo G. An alpha-helical lid guides the target DNA toward catalysis in CRISPR-Cas12a. Nat Commun 2024; 15:1473. [PMID: 38368461 PMCID: PMC10874386 DOI: 10.1038/s41467-024-45762-6] [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: 03/07/2023] [Accepted: 02/01/2024] [Indexed: 02/19/2024] Open
Abstract
CRISPR-Cas12a is a powerful RNA-guided genome-editing system that generates double-strand DNA breaks using its single RuvC nuclease domain by a sequential mechanism in which initial cleavage of the non-target strand is followed by target strand cleavage. How the spatially distant DNA target strand traverses toward the RuvC catalytic core is presently not understood. Here, continuous tens of microsecond-long molecular dynamics and free-energy simulations reveal that an α-helical lid, located within the RuvC domain, plays a pivotal role in the traversal of the DNA target strand by anchoring the crRNA:target strand duplex and guiding the target strand toward the RuvC core, as also corroborated by DNA cleavage experiments. In this mechanism, the REC2 domain pushes the crRNA:target strand duplex toward the core of the enzyme, while the Nuc domain aids the bending and accommodation of the target strand within the RuvC core by bending inward. Understanding of this critical process underlying Cas12a activity will enrich fundamental knowledge and facilitate further engineering strategies for genome editing.
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Affiliation(s)
- Aakash Saha
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA, 52512, USA
| | - Mohd Ahsan
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA, 52512, USA
| | - Pablo R Arantes
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA, 52512, USA
| | - Michael Schmitz
- Department of Biochemistry, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland
| | - Christelle Chanez
- Department of Biochemistry, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland
| | - Martin Jinek
- Department of Biochemistry, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland
| | - Giulia Palermo
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA, 52512, USA.
- Department of Chemistry, University of California Riverside, 900 University Avenue, Riverside, CA, 52512, USA.
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8
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Kovalev MA, Davletshin AI, Karpov DS. Engineering Cas9: next generation of genomic editors. Appl Microbiol Biotechnol 2024; 108:209. [PMID: 38353732 PMCID: PMC10866799 DOI: 10.1007/s00253-024-13056-y] [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: 06/13/2023] [Revised: 02/05/2024] [Accepted: 02/06/2024] [Indexed: 02/16/2024]
Abstract
The Cas9 endonuclease of the CRISPR/Cas type IIA system from Streptococcus pyogenes is the heart of genome editing technology that can be used to treat human genetic and viral diseases. Despite its large size and other drawbacks, S. pyogenes Cas9 remains the most widely used genome editor. A vast amount of research is aimed at improving Cas9 as a promising genetic therapy. Strategies include directed evolution of the Cas9 protein, rational design, and domain swapping. The first generation of Cas9 editors comes directly from the wild-type protein. The next generation is obtained by combining mutations from the first-generation variants, adding new mutations to them, or refining mutations. This review summarizes and discusses recent advances and ways in the creation of next-generation genomic editors derived from S. pyogenes Cas9. KEY POINTS: • The next-generation Cas9-based editors are more active than in the first one. • PAM-relaxed variants of Cas9 are improved by increased specificity and activity. • Less mutagenic and immunogenic variants of Cas9 are created.
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Affiliation(s)
- Maxim A Kovalev
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov Str., 32, 119991, Moscow, Russia
- Department of Biology, Lomonosov Moscow State University, 119234, Moscow, Russia
| | - Artem I Davletshin
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov Str., 32, 119991, Moscow, Russia
| | - Dmitry S Karpov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov Str., 32, 119991, Moscow, Russia.
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov Str., 32, 119991, Moscow, Russia.
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9
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Khuttan S, Gallicchio E. What to Make of Zero: Resolving the Statistical Noise from Conformational Reorganization in Alchemical Binding Free Energy Estimates with Metadynamics Sampling. J Chem Theory Comput 2024; 20:1489-1501. [PMID: 38252868 PMCID: PMC10867849 DOI: 10.1021/acs.jctc.3c01250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 01/03/2024] [Accepted: 01/03/2024] [Indexed: 01/24/2024]
Abstract
We introduce the self-relative binding free energy (self-RBFE) approach to evaluate the intrinsic statistical variance of dual-topology alchemical binding free energy estimators. The self-RBFE is the relative binding free energy between a ligand and a copy of the same ligand, and its true value is zero. Nevertheless, because the two copies of the ligand move independently, the self-RBFE value produced by a finite-length simulation fluctuates and can be used to measure the variance of the model. The results of this validation provide evidence that a significant fraction of the errors observed in benchmark studies reflect the statistical fluctuations of unconverged estimates rather than the models' accuracy. Furthermore, we find that ligand reorganization is a significant contributing factor to the statistical variance of binding free energy estimates and that metadynamics-accelerated conformational sampling of the torsional degrees of freedom of the ligand can drastically reduce the time to convergence.
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Affiliation(s)
- Sheenam Khuttan
- Department
of Chemistry and Biochemistry, Brooklyn
College of the City University of New York, New York, New York 11210, United States
- Ph.D.
Program in Biochemistry, The Graduate Center
of the City University of New York, New York, New York 10016, United States
| | - Emilio Gallicchio
- Department
of Chemistry and Biochemistry, Brooklyn
College of the City University of New York, New York, New York 11210, United States
- Ph.D.
Program in Biochemistry, The Graduate Center
of the City University of New York, New York, New York 10016, United States
- Ph.D.
Program in Chemistry, The Graduate Center
of the City University of New York, New York, New York 10016, United States
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10
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Kaur R, Wetmore SD. Is Metal Stabilization of the Leaving Group Required or Can Lysine Facilitate Phosphodiester Bond Cleavage in Nucleic Acids? A Computational Study of EndoV. J Chem Inf Model 2024; 64:944-959. [PMID: 38253321 DOI: 10.1021/acs.jcim.3c01775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Endonuclease V (EndoV) is a single-metal-dependent enzyme that repairs deaminated DNA nucleobases in cells by cleaving the phosphodiester bond, and this enzyme has proven to be a powerful tool in biotechnology and medicine. The catalytic mechanism used by EndoV must be understood to design new disease detection and therapeutic solutions and further exploit the enzyme in interdisciplinary applications. This study has used a mixed molecular dynamics (MD) and quantum mechanics/molecular mechanics (QM/MM) approach to compare eight distinct catalytic pathways and provides the first proposed mechanism for bacterial EndoV. The calculations demonstrate that mechanisms involving either direct or indirect metal coordination to the leaving group of the substrate previously proposed for other nucleases are unlikely for EndoV, regardless of the general base (histidine, aspartate, and substrate phosphate moiety). Instead, distinct catalytic pathways are characterized for EndoV that involve K139 stabilizing the leaving group, a metal-coordinated water stabilizing the transition structure, and either H214 or a substrate phosphate group activating the water nucleophile. In silico K139A and H214A mutational results support the newly proposed roles of these residues. Although this is a previously unseen combination of general base, general acid, and metal-binding architecture for a one-metal-dependent endonuclease, our proposed catalytic mechanisms are fully consistent with experimental kinetic, structural, and mutational data. In addition to substantiating a growing body of literature, suggesting that one metal is enough to catalyze P-O bond cleavage in nucleic acids, this new fundamental understanding of the catalytic function will promote the exploration of new and improved applications of EndoV.
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Affiliation(s)
- Rajwinder Kaur
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4, Canada
| | - Stacey D Wetmore
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4, Canada
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11
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Madugula SS, Pujar P, Bharani N, Wang S, Jayasinghe-Arachchige VM, Pham T, Mashburn D, Artilis M, Liu J. Identification of Family-Specific Features in Cas9 and Cas12 Proteins: A Machine Learning Approach Using Complete Protein Feature Spectrum. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.22.576286. [PMID: 38328240 PMCID: PMC10849529 DOI: 10.1101/2024.01.22.576286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
The recent development of CRISPR-Cas technology holds promise to correct gene-level defects for genetic diseases. The key element of the CRISPR-Cas system is the Cas protein, a nuclease that can edit the gene of interest assisted by guide RNA. However, these Cas proteins suffer from inherent limitations like large size, low cleavage efficiency, and off-target effects, hindering their widespread application as a gene editing tool. Therefore, there is a need to identify novel Cas proteins with improved editing properties, for which it is necessary to understand the underlying features governing the Cas families. In the current study, we aim to elucidate the unique protein attributes associated with Cas9 and Cas12 families and identify the features that distinguish each family from the other. Here, we built Random Forest (RF) binary classifiers to distinguish Cas12 and Cas9 proteins from non-Cas proteins, respectively, using the complete protein feature spectrum (13,495 features) encoding various physiochemical, topological, constitutional, and coevolutionary information of Cas proteins. Furthermore, we built multiclass RF classifiers differentiating Cas9, Cas12, and Non-Cas proteins. All the models were evaluated rigorously on the test and independent datasets. The Cas12 and Cas9 binary models achieved a high overall accuracy of 95% and 97% on their respective independent datasets, while the multiclass classifier achieved a high F1 score of 0.97. We observed that Quasi-sequence-order descriptors like Schneider-lag descriptors and Composition descriptors like charge, volume, and polarizability are essential for the Cas12 family. More interestingly, we discovered that Amino Acid Composition descriptors, especially the Tripeptide Composition (TPC) descriptors, are important for the Cas9 family. Four of the identified important descriptors of Cas9 classification are tripeptides PWN, PYY, HHA, and DHI, which are seen to be conserved across all the Cas9 proteins and were located within different catalytically important domains of the Cas9 protein structure. Among these four tripeptides, tripeptides DHI and HHA are well-known to be involved in the DNA cleavage activity of the Cas9 protein. We therefore propose the the other two tripeptides, PWN and PYY, may also be essential for the Cas9 family. Our identified important descriptors enhanced the understanding of the catalytic mechanisms of Cas9 and Cas12 proteins and provide valuable insights into design of novel Cas systems to achieve enhanced gene-editing properties.
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Affiliation(s)
- Sita Sirisha Madugula
- Department of Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Pranav Pujar
- Department of Industrial, Manufacturing and Systems Engineering, University of Texas at Arlington, Arlington, Texas, United States
| | - Nammi Bharani
- Department of Industrial, Manufacturing and Systems Engineering, University of Texas at Arlington, Arlington, Texas, United States
| | - Shouyi Wang
- Department of Industrial, Manufacturing and Systems Engineering, University of Texas at Arlington, Arlington, Texas, United States
| | - Vindi M. Jayasinghe-Arachchige
- Department of Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Tyler Pham
- Graduate School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, Texas
| | - Dominic Mashburn
- Department of Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Maria Artilis
- Department of Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Jin Liu
- Department of Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas, United States
- Graduate School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, Texas
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12
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Chen L, Wu Y, Wu C, Silveira A, Sherman W, Xu H, Gallicchio E. Performance and Analysis of the Alchemical Transfer Method for Binding-Free-Energy Predictions of Diverse Ligands. J Chem Inf Model 2024; 64:250-264. [PMID: 38147877 DOI: 10.1021/acs.jcim.3c01705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2023]
Abstract
The Alchemical Transfer Method (ATM) is herein validated against the relative binding-free energies (RBFEs) of a diverse set of protein-ligand complexes. We employed a streamlined setup workflow, a bespoke force field, and AToM-OpenMM software to compute the RBFEs of the benchmark set prepared by Schindler and collaborators at Merck KGaA. This benchmark set includes examples of standard small R-group ligand modifications as well as more challenging scenarios, such as large R-group changes, scaffold hopping, formal charge changes, and charge-shifting transformations. The novel coordinate perturbation scheme and a dual-topology approach of ATM address some of the challenges of single-topology alchemical RBFE methods. Specifically, ATM eliminates the need for splitting electrostatic and Lennard-Jones interactions, atom mapping, defining ligand regions, and postcorrections for charge-changing perturbations. Thus, ATM is simpler and more broadly applicable than conventional alchemical methods, especially for scaffold-hopping and charge-changing transformations. Here, we performed well over 500 RBFE calculations for eight protein targets and found that ATM achieves accuracy comparable to that of existing state-of-the-art methods, albeit with larger statistical fluctuations. We discuss insights into the specific strengths and weaknesses of the ATM method that will inform future deployments. This study confirms that ATM can be applied as a production tool for RBFE predictions across a wide range of perturbation types within a unified, open-source framework.
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Affiliation(s)
- Lieyang Chen
- Roivant Sciences, 151 W 42nd Street, 15th Floor, New York, New York 10036, United States
| | - Yujie Wu
- Roivant Sciences, 151 W 42nd Street, 15th Floor, New York, New York 10036, United States
- Atommap Corporation, New York, New York 10017, United States
| | - Chuanjie Wu
- Roivant Sciences, 151 W 42nd Street, 15th Floor, New York, New York 10036, United States
| | - Ana Silveira
- Psivant Therapeutics, 451 D Street, Boston, Massachusetts 02210, United States
| | - Woody Sherman
- Psivant Therapeutics, 451 D Street, Boston, Massachusetts 02210, United States
| | - Huafeng Xu
- Roivant Sciences, 151 W 42nd Street, 15th Floor, New York, New York 10036, United States
- Atommap Corporation, New York, New York 10017, United States
| | - Emilio Gallicchio
- Department of Chemistry and Biochemistry, Brooklyn College of the City University of New York, New York, New York 11210, United States
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, New York 10016, United States
- Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, New York, New York 10016, United States
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13
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Wang J, Maschietto F, Qiu T, Arantes PR, Skeens E, Palermo G, Lisi GP, Batista VS. Substrate-independent activation pathways of the CRISPR-Cas9 HNH nuclease. Biophys J 2023; 122:4635-4644. [PMID: 37936350 PMCID: PMC10754686 DOI: 10.1016/j.bpj.2023.11.005] [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: 07/13/2023] [Revised: 10/29/2023] [Accepted: 11/03/2023] [Indexed: 11/09/2023] Open
Abstract
A hallmark of tightly regulated high-fidelity enzymes is that they become activated only after encountering cognate substrates, often by an induced-fit mechanism rather than conformational selection. Upon analysis of molecular dynamics trajectories, we recently discovered that the Cas9 HNH domain exists in three conformations: 1) Y836 (which is two residues away from the catalytic D839 and H840 residues) is hydrogen bonded to the D829 backbone amide, 2) Y836 is hydrogen bonded to the backbone amide of D861 (which is one residue away from the third catalytic residue N863), and 3) Y836 is not hydrogen bonded to either residue. Each of the three conformers differs from the active state of HNH. The conversion between the inactive and active states involves a local unfolding-refolding process that displaces the Cα and side chain of the catalytic N863 residue by ∼5 Å and ∼10 Å, respectively. In this study, we report the two largest principal components of coordinate variance of the HNH domain throughout molecular dynamics trajectories to establish the interconversion pathways of these conformations. We show that conformation 2 is an obligate step between conformations 1 and 3, which are not directly interconvertible without conformation 2. The loss of hydrogen bonding of the Y836 side chain in conformation 3 likely plays an essential role in activation during local unfolding-refolding of an α-helix containing the catalytic N863. Three single Lys-to-Ala mutants appear to eliminate this substrate-independent activation pathway of the wild-type HNH nuclease, thereby enhancing the fidelity of HNH cleavage.
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Affiliation(s)
- Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut.
| | | | - Tianyin Qiu
- Department of Chemistry, Yale University, New Haven, Connecticut
| | - Pablo R Arantes
- Department of Bioengineering, University of California, Riverside, Riverside, California
| | - Erin Skeens
- Department of Chemistry, University of California, Riverside, Riverside, California
| | - Giulia Palermo
- Department of Bioengineering, University of California, Riverside, Riverside, California; Department of Chemistry, University of California, Riverside, Riverside, California.
| | - George P Lisi
- Department of Molecular and Cell Biology and Biochemistry, Brown University, Providence, Rhode Island.
| | - Victor S Batista
- Department of Chemistry, Yale University, New Haven, Connecticut.
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14
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Lu X, Lan X, Lu S, Zhang J. Progressive computational approaches to facilitate decryption of allosteric mechanism and drug discovery. Curr Opin Struct Biol 2023; 83:102701. [PMID: 37716092 DOI: 10.1016/j.sbi.2023.102701] [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: 07/12/2023] [Revised: 08/17/2023] [Accepted: 08/21/2023] [Indexed: 09/18/2023]
Abstract
Allostery is a ubiquitous biological phenomenon where perturbation at topologically distal areas of a protein serves as a trigger to fine-tune the orthosteric site and thus regulate protein function. The investigation of allosteric regulation greatly enhances our understanding of human diseases and broadens avenue for drug discovery. For decades, owing to the difficulty in allostery characterization through serendipitous experimental screening, researchers have developed several innovative computational approaches, which proves to accelerate the elucidation of allostery. Herein, we review the state-of-the-art advance of computational methodologies for allostery study, with particular emphasis on promising trends emerging over the past two years. We expect this review will outline the latest landscape of allostery study and inspire researchers to further facilitate this field.
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Affiliation(s)
- Xun Lu
- School of Pharmacy, Ningxia Medical University, Yinchuan 750004, China; State Key Laboratory of Medical Genomics, National Research Center for Translational Medicine at Shanghai, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Medicinal Chemistry and Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xiaobing Lan
- School of Pharmacy, Ningxia Medical University, Yinchuan 750004, China
| | - Shaoyong Lu
- School of Pharmacy, Ningxia Medical University, Yinchuan 750004, China; State Key Laboratory of Medical Genomics, National Research Center for Translational Medicine at Shanghai, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Medicinal Chemistry and Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jian Zhang
- School of Pharmacy, Ningxia Medical University, Yinchuan 750004, China; State Key Laboratory of Medical Genomics, National Research Center for Translational Medicine at Shanghai, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; Medicinal Chemistry and Bioinformatics Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China.
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15
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Newsom SN, Wang DS, Rostami S, Schuster I, Parameshwaran HP, Joseph YG, Qin PZ, Liu J, Rajan R. Differential Divalent Metal Binding by SpyCas9's RuvC Active Site Contributes to Nonspecific DNA Cleavage. CRISPR J 2023; 6:527-542. [PMID: 38108519 PMCID: PMC10753984 DOI: 10.1089/crispr.2023.0022] [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: 04/07/2023] [Accepted: 11/10/2023] [Indexed: 12/19/2023] Open
Abstract
To protect against mobile genetic elements (MGEs), some bacteria and archaea have clustered regularly interspaced short palindromic repeats-CRISPR associated (CRISPR-Cas) adaptive immune systems. CRISPR RNAs (crRNAs) bound to Cas nucleases hybridize to MGEs based on sequence complementarity to guide the nucleases to cleave the MGEs. This programmable DNA cleavage has been harnessed for gene editing. Safety concerns include off-target and guide RNA (gRNA)-free DNA cleavages, both of which are observed in the Cas nuclease commonly used for gene editing, Streptococcus pyogenes Cas9 (SpyCas9). We developed a SpyCas9 variant (SpyCas9H982A) devoid of gRNA-free DNA cleavage activity that is more selective for on-target cleavage. The H982A substitution in the metal-dependent RuvC active site reduces Mn2+-dependent gRNA-free DNA cleavage by ∼167-fold. Mechanistic molecular dynamics analysis shows that Mn2+, but not Mg2+, produces a gRNA-free DNA cleavage competent state that is disrupted by the H982A substitution. Our study demonstrates the feasibility of modulating cation:protein interactions to engineer safer gene editing tools.
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Affiliation(s)
- Sydney N. Newsom
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, The University of Oklahoma, Norman, Oklahoma, USA
| | - Duen-Shian Wang
- Department of Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Saadi Rostami
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, The University of Oklahoma, Norman, Oklahoma, USA
| | - Isabelle Schuster
- Department of Chemistry, University of Southern California, Los Angeles, California, USA
| | - Hari Priya Parameshwaran
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, The University of Oklahoma, Norman, Oklahoma, USA
| | - Yadin G. Joseph
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, The University of Oklahoma, Norman, Oklahoma, USA
| | - Peter Z. Qin
- Department of Chemistry, University of Southern California, Los Angeles, California, USA
| | - Jin Liu
- Department of Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Rakhi Rajan
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, The University of Oklahoma, Norman, Oklahoma, USA
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16
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Noshay J, Walker T, Alexander W, Klingeman D, Romero J, Walker A, Prates E, Eckert C, Irle S, Kainer D, Jacobson D. Quantum biological insights into CRISPR-Cas9 sgRNA efficiency from explainable-AI driven feature engineering. Nucleic Acids Res 2023; 51:10147-10161. [PMID: 37738140 PMCID: PMC10602897 DOI: 10.1093/nar/gkad736] [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: 07/08/2022] [Revised: 08/07/2023] [Accepted: 08/29/2023] [Indexed: 09/24/2023] Open
Abstract
CRISPR-Cas9 tools have transformed genetic manipulation capabilities in the laboratory. Empirical rules-of-thumb have been developed for only a narrow range of model organisms, and mechanistic underpinnings for sgRNA efficiency remain poorly understood. This work establishes a novel feature set and new public resource, produced with quantum chemical tensors, for interpreting and predicting sgRNA efficiency. Feature engineering for sgRNA efficiency is performed using an explainable-artificial intelligence model: iterative Random Forest (iRF). By encoding quantitative attributes of position-specific sequences for Escherichia coli sgRNAs, we identify important traits for sgRNA design in bacterial species. Additionally, we show that expanding positional encoding to quantum descriptors of base-pair, dimer, trimer, and tetramer sequences captures intricate interactions in local and neighboring nucleotides of the target DNA. These features highlight variation in CRISPR-Cas9 sgRNA dynamics between E. coli and H. sapiens genomes. These novel encodings of sgRNAs enhance our understanding of the elaborate quantum biological processes involved in CRISPR-Cas9 machinery.
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Affiliation(s)
- Jaclyn M Noshay
- Computational and Predictive Biology, Biosciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Tyler Walker
- Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee-Knoxville, Knoxville, TN, USA
| | - William G Alexander
- Synthetic Biology, Biosciences,Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Dawn M Klingeman
- Synthetic Biology, Biosciences,Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Jonathon Romero
- Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee-Knoxville, Knoxville, TN, USA
| | - Angelica M Walker
- Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee-Knoxville, Knoxville, TN, USA
| | - Erica Prates
- Computational and Predictive Biology, Biosciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Carrie Eckert
- Synthetic Biology, Biosciences,Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Stephan Irle
- Computational Sciences and Engineering, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - David Kainer
- Computational and Predictive Biology, Biosciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Daniel A Jacobson
- Computational and Predictive Biology, Biosciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA
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17
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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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18
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Raghavan B, Paulikat M, Ahmad K, Callea L, Rizzi A, Ippoliti E, Mandelli D, Bonati L, De Vivo M, Carloni P. Drug Design in the Exascale Era: A Perspective from Massively Parallel QM/MM Simulations. J Chem Inf Model 2023. [PMID: 37319347 DOI: 10.1021/acs.jcim.3c00557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The initial phases of drug discovery - in silico drug design - could benefit from first principle Quantum Mechanics/Molecular Mechanics (QM/MM) molecular dynamics (MD) simulations in explicit solvent, yet many applications are currently limited by the short time scales that this approach can cover. Developing scalable first principle QM/MM MD interfaces fully exploiting current exascale machines - so far an unmet and crucial goal - will help overcome this problem, opening the way to the study of the thermodynamics and kinetics of ligand binding to protein with first principle accuracy. Here, taking two relevant case studies involving the interactions of ligands with rather large enzymes, we showcase the use of our recently developed massively scalable Multiscale Modeling in Computational Chemistry (MiMiC) QM/MM framework (currently using DFT to describe the QM region) to investigate reactions and ligand binding in enzymes of pharmacological relevance. We also demonstrate for the first time strong scaling of MiMiC-QM/MM MD simulations with parallel efficiency of ∼70% up to >80,000 cores. Thus, among many others, the MiMiC interface represents a promising candidate toward exascale applications by combining machine learning with statistical mechanics based algorithms tailored for exascale supercomputers.
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Affiliation(s)
- Bharath Raghavan
- Computational Biomedicine, Institute of Advanced Simulations IAS-5/Institute for Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH, Jülich 52428, Germany
- Department of Physics, RWTH Aachen University, Aachen 52074, Germany
| | - Mirko Paulikat
- Computational Biomedicine, Institute of Advanced Simulations IAS-5/Institute for Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH, Jülich 52428, Germany
| | - Katya Ahmad
- Computational Biomedicine, Institute of Advanced Simulations IAS-5/Institute for Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH, Jülich 52428, Germany
| | - Lara Callea
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milan, Italy
| | - Andrea Rizzi
- Computational Biomedicine, Institute of Advanced Simulations IAS-5/Institute for Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH, Jülich 52428, Germany
- Atomistic Simulations, Italian Institute of Technology, Genova 16163, Italy
| | - Emiliano Ippoliti
- Computational Biomedicine, Institute of Advanced Simulations IAS-5/Institute for Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH, Jülich 52428, Germany
| | - Davide Mandelli
- Computational Biomedicine, Institute of Advanced Simulations IAS-5/Institute for Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH, Jülich 52428, Germany
| | - Laura Bonati
- Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126 Milan, Italy
| | - Marco De Vivo
- Molecular Modelling and Drug Discovery, Italian Institute of Technology, Genova 16163, Italy
| | - Paolo Carloni
- Computational Biomedicine, Institute of Advanced Simulations IAS-5/Institute for Neuroscience and Medicine INM-9, Forschungszentrum Jülich GmbH, Jülich 52428, Germany
- Department of Physics and Universitätsklinikum, RWTH Aachen University, Aachen 52074, Germany
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19
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Das CK, Gupta A, Nair NN. Probing the general base for DNA polymerization in telomerase: a molecular dynamics investigation. Phys Chem Chem Phys 2023; 25:14147-14157. [PMID: 37162325 DOI: 10.1039/d3cp00521f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Telomerase is an RNA-dependent DNA polymerase that plays a role in the maintenance of the 3' end of the eukaryotic chromosome, known as a telomere, by catalyzing the DNA polymerization reaction in cancer and embryonic stem cells. The detailed molecular details of the DNA polymerization by telomerase, especially the general base for deprotonating the terminal 3'-hydroxyl, which triggers the chemical reaction, remain elusive. We conducted a computational investigation using hybrid quantum mechanical/molecular mechanical (QM/MM) molecular dynamics (MD) simulations to probe the detailed mechanism of the reaction. Our simulations started with the telomerase:RNA:DNA:dNTP ternary complex, and by using enhanced sampling QM/MM MD simulations, we probed the general base involved directly in the polymerization. We report the participation of an aspartate (Asp344) coordinated to Mg and an active site water molecule, jointly acting as a base during nucleic acid addition. The Asp344 residue remains transiently protonated during the course of the reaction, and later it deprotonates by transferring its proton to the water at the end of the reaction.
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Affiliation(s)
- Chandan Kumar Das
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India.
| | - Abhinav Gupta
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India.
| | - Nisanth N Nair
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India.
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20
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Spasskaya DS, Davletshin AI, Bachurin SS, Tutyaeva VV, Garbuz DG, Karpov DS. Improving the on-target activity of high-fidelity Cas9 editors by combining rational design and random mutagenesis. Appl Microbiol Biotechnol 2023; 107:2385-2401. [PMID: 36917274 DOI: 10.1007/s00253-023-12469-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 02/24/2023] [Accepted: 02/28/2023] [Indexed: 03/16/2023]
Abstract
Genomic and post-genomic editors based on CRISPR/Cas systems are widely used in basic research and applied sciences, including human gene therapy. Most genome editing tools are based on the CRISPR/Cas9 type IIA system from Streptococcus pyogenes. Unfortunately, a number of drawbacks have hindered its application in therapeutic approaches, the most serious of which is the relatively high level of off-targets. To overcome this obstacle, various high-fidelity Cas9 variants have been created. However, they show reduced on-target activity compared to wild-type Cas9 possibly due to increased sensitivity to eukaryotic chromatin. Here, we combined a rational approach with random mutagenesis to create a set of new Cas9 variants showing high specificity and increased activity in Saccharomyces cerevisiae yeast. Moreover, a novel mutation in the PAM (protospacer adjacent motif)-interacting Cas9 domain was found, which increases the on-target activity of high-fidelity Cas9 variants while retaining their high specificity. The obtained data suggest that this mutation acts by weakening the eukaryotic chromatin barrier for Cas9 and rearranging the RuvC active center. Improved Cas9 variants should further advance genome and post-genome editing technologies. KEY POINTS: • D147Y and P411T mutations increase the activity of high-fidelity Cas9 variants. • The new L1206P mutation further increases the activity of high-fidelity Cas9 variants. • The L1206P mutation weakens the chromatin barrier for Cas9 editors.
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Affiliation(s)
- Daria S Spasskaya
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology Russian Academy of Sciences, Vavilov St. 32, Moscow, 119991, Russia
| | - Artem I Davletshin
- Engelhardt Institute of Molecular Biology Russian Academy of Sciences, Vavilov St. 32, Moscow, 119991, Russia
| | - Stanislav S Bachurin
- FSBEI HE Rostov State Medical University Ministry of Health, Nakhichevanskiy Lane 29, Rostov-On-Don, 344022, Russia
| | - Vera V Tutyaeva
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology Russian Academy of Sciences, Vavilov St. 32, Moscow, 119991, Russia
| | - David G Garbuz
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology Russian Academy of Sciences, Vavilov St. 32, Moscow, 119991, Russia
| | - Dmitry S Karpov
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology Russian Academy of Sciences, Vavilov St. 32, Moscow, 119991, Russia.
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21
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Zhang C, Wang X, Liu G, Ren H, Liu J, Jiang Z, Zhang Y. CRISPR/Cas9 and Chlorophyll Coordination Micelles for Cancer Treatment by Genome Editing and Photodynamic Therapy. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2206981. [PMID: 36693779 DOI: 10.1002/smll.202206981] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/27/2022] [Indexed: 06/17/2023]
Abstract
CRISPR/Cas9-based gene therapy and photodynamic therapy both show promise for cancer treatment but still have their drawbacks limited by tumor microenvironment and long treatment duration. Herein, CRISPR/Cas9 genome editing and photodynamic strategy for a synergistic anti-tumor therapeutic modality is merged. Chlorophyll (Chl) extracted from natural green vegetables is encapsulated in Pluronic F127 (F127) micelles and Histidine-tagged Cas9 can be effectively chelated onto micelles via metal coordination by simple incubation, affording Cas9-Chl@F127 micelles. Mg2+ acts as an enzyme cofactor to correlatively enhance Cas9 gene-editing activity. Upon laser irradiation, Chl as an effective photosensitizer generates reactive oxygen species (ROS) to kill tumor cells. Meanwhile, CRISPR/Cas9, mediated by dual deliberately designed gRNAs of APE1 and NRF2, can reprogram the tumor microenvironment by increasing the intracellular oxygen accumulation and impairing the oxidative defense system of tumor cells. Cas9-Chl@F127 micelles can responsively release Cas9 in the presence of abundant ATP or low pH in tumor cells. In a murine tumor model, Cas9-Chl@F127 complexed with dual gRNAs including APE1 and NRF2 significantly inhibits the tumor growth. Taken together, Cas9-Chl@F127 micelles, representing the first Chl-based green biomaterial for the delivery of Cas9, show great promise for the synergistic anti-tumor treatment by PDT and gene editing.
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Affiliation(s)
- Chen Zhang
- School of Chemical Engineering and Technology, Key Laboratory of Systems Bioengineering (Ministry of Education), Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, 300350, P. R. China
| | - Xiaojie Wang
- School of Chemical Engineering and Technology, Key Laboratory of Systems Bioengineering (Ministry of Education), Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, 300350, P. R. China
| | - Gengqi Liu
- School of Chemical Engineering and Technology, Key Laboratory of Systems Bioengineering (Ministry of Education), Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, 300350, P. R. China
| | - He Ren
- School of Chemical Engineering and Technology, Key Laboratory of Systems Bioengineering (Ministry of Education), Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, 300350, P. R. China
| | - Jingang Liu
- School of Chemical Engineering and Technology, Key Laboratory of Systems Bioengineering (Ministry of Education), Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, 300350, P. R. China
| | - Zhen Jiang
- School of Chemical Engineering and Technology, Key Laboratory of Systems Bioengineering (Ministry of Education), Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, 300350, P. R. China
| | - Yumiao Zhang
- School of Chemical Engineering and Technology, Key Laboratory of Systems Bioengineering (Ministry of Education), Frontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin University, Tianjin, 300350, P. R. China
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22
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Sinha S, Pindi C, Ahsan M, Arantes PR, Palermo G. Machines on Genes through the Computational Microscope. J Chem Theory Comput 2023; 19:1945-1964. [PMID: 36947696 PMCID: PMC10104023 DOI: 10.1021/acs.jctc.2c01313] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/24/2023]
Abstract
Macromolecular machines acting on genes are at the core of life's fundamental processes, including DNA replication and repair, gene transcription and regulation, chromatin packaging, RNA splicing, and genome editing. Here, we report the increasing role of computational biophysics in characterizing the mechanisms of "machines on genes", focusing on innovative applications of computational methods and their integration with structural and biophysical experiments. We showcase how state-of-the-art computational methods, including classical and ab initio molecular dynamics to enhanced sampling techniques, and coarse-grained approaches are used for understanding and exploring gene machines for real-world applications. As this review unfolds, advanced computational methods describe the biophysical function that is unseen through experimental techniques, accomplishing the power of the "computational microscope", an expression coined by Klaus Schulten to highlight the extraordinary capability of computer simulations. Pushing the frontiers of computational biophysics toward a pragmatic representation of large multimegadalton biomolecular complexes is instrumental in bridging the gap between experimentally obtained macroscopic observables and the molecular principles playing at the microscopic level. This understanding will help harness molecular machines for medical, pharmaceutical, and biotechnological purposes.
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23
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Nierzwicki Ł, Ahsan M, Palermo G. The Electronic Structure of Genome Editors from the First Principles. ELECTRONIC STRUCTURE (BRISTOL, ENGLAND) 2023; 5:014003. [PMID: 36926635 PMCID: PMC10016068 DOI: 10.1088/2516-1075/acb410] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Genome editing based on the CRISPR-Cas9 system has paved new avenues for medicine, pharmaceutics, biotechnology, and beyond. This article reports the role of first-principles (ab-initio) molecular dynamics (MD) in the CRISPR-Cas9 revolution, achieving a profound understanding of the enzymatic function and offering valuable insights for enzyme engineering. We introduce the methodologies and explain the use of ab-initio MD simulations to characterize the two-metal dependent mechanism of DNA cleavage in the RuvC domain of the Cas9 enzyme, and how a second catalytic domain, HNH, cleaves the target DNA with the aid of a single metal ion. A detailed description of how ab-initio MD is combined with free-energy methods - i.e., thermodynamic integration and metadynamics - to break and form chemical bonds is given, explaining the use of these methods to determine the chemical landscape and establish the catalytic mechanism in CRISPR-Cas9. The critical role of classical methods is also discussed, explaining theory and application of constant pH MD simulations, used to accurately predict the catalytic residues' protonation states. Overall, first-principles methods are shown to unravel the electronic structure of the Cas9 enzyme, providing valuable insights that can serve for the design of genome editing tools with improved catalytic efficiency or controllable activity.
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Affiliation(s)
- Łukasz Nierzwicki
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA 52512, United States
| | - Mohd Ahsan
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA 52512, United States
| | - Giulia Palermo
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA 52512, United States
- Department of Chemistry, University of California Riverside, 900 University Avenue, Riverside, CA 52512, United States
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24
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Csizi K, Reiher M. Universal
QM
/
MM
approaches for general nanoscale applications. WIRES COMPUTATIONAL MOLECULAR SCIENCE 2023. [DOI: 10.1002/wcms.1656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
| | - Markus Reiher
- Laboratorium für Physikalische Chemie ETH Zürich Zürich Switzerland
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25
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Bhattacharya S, Satpati P. Insights into the Mechanism of CRISPR/Cas9-Based Genome Editing from Molecular Dynamics Simulations. ACS OMEGA 2023; 8:1817-1837. [PMID: 36687047 PMCID: PMC9850488 DOI: 10.1021/acsomega.2c05583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 11/22/2022] [Indexed: 06/17/2023]
Abstract
The CRISPR/Cas9 system is a popular genome-editing tool with immense therapeutic potential. It is a simple two-component system (Cas9 protein and RNA) that recognizes the DNA sequence on the basis of RNA:DNA complementarity, and the Cas9 protein catalyzes the double-stranded break in the DNA. In the past decade, near-atomic resolution structures at various stages of the CRISPR/Cas9 DNA editing pathway have been reported along with numerous experimental and computational studies. Such studies have boosted knowledge of the genome-editing mechanism. Despite such advancements, the application of CRISPR/Cas9 in therapeutics is still limited, primarily due to off-target effects. Several studies aim at engineering high-fidelity Cas9 to minimize the off-target effects. Molecular Dynamics (MD) simulations have been an excellent complement to the experimental studies for investigating the mechanism of CRISPR/Cas9 editing in terms of structure, thermodynamics, and kinetics. MD-based studies have uncovered several important molecular aspects of Cas9, such as nucleotide binding, catalytic mechanism, and off-target effects. In this Review, the contribution of MD simulation to understand the CRISPR/Cas9 mechanism has been discussed, preceded by an overview of the history, mechanism, and structural aspects of the CRISPR/Cas9 system. These studies are important for the rational design of highly specific Cas9 and will also be extremely promising for achieving more accurate genome editing in the future.
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26
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Kaur R, Nikkel DJ, Aboelnga MM, Wetmore SD. The Impact of DFT Functional, Cluster Model Size, and Implicit Solvation on the Structural Description of Single-Metal-Mediated DNA Phosphodiester Bond Cleavage: The Case Study of APE1. J Phys Chem B 2022; 126:10672-10683. [PMID: 36485014 DOI: 10.1021/acs.jpcb.2c06756] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Phosphodiester bond hydrolysis in nucleic acids is a ubiquitous reaction that can be facilitated by enzymes called nucleases, which often use metal ions to achieve catalytic function. While a two-metal-mediated pathway has been well established for many enzymes, there is growing support that some enzymes require only one metal for the catalytic step. Using human apurinic/apyrimidinic endonuclease (APE1) as a prototypical example and cluster models, this study clarifies the impact of DFT functional, cluster model size, and implicit solvation on single-metal-mediated phosphodiester bond cleavage and provides insight into how to efficiently model this chemistry. Initially, a model containing 69 atoms built from a high-resolution X-ray crystal structure is used to explore the reaction pathway mapped by a range of DFT functionals and basis sets, which provides support for the use of standard functionals (M06-2X and B3LYP-D3) to study this reaction. Subsequently, systematically increasing the model size to 185 atoms by including additional amino acids and altering residue truncation points highlights that small models containing only a few amino acids or β carbon truncation points introduce model strains and lead to incorrect metal coordination. Indeed, a model that contains all key residues (general base and acid, residues that stabilize the substrate, and amino acids that maintain the metal coordination) is required for an accurate structural depiction of the one-metal-mediated phosphodiester bond hydrolysis by APE1, which results in 185 atoms. The additional inclusion of the broader enzyme environment through continuum solvation models has negligible effects. The insights gained in the present work can be used to direct future computational studies of other one-metal-dependent nucleases to provide a greater understanding of how nature achieves this difficult chemistry.
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Affiliation(s)
- Rajwinder Kaur
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4, Canada
| | - Dylan J Nikkel
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4, Canada
| | - Mohamed M Aboelnga
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4, Canada.,Chemistry Department, Faculty of Science, Damietta University, New Damietta 34517, Egypt
| | - Stacey D Wetmore
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive West, Lethbridge, Alberta T1K 3M4, Canada
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27
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Wu WY, Mohanraju P, Liao C, Adiego-Pérez B, Creutzburg SCA, Makarova KS, Keessen K, Lindeboom TA, Khan TS, Prinsen S, Joosten R, Yan WX, Migur A, Laffeber C, Scott DA, Lebbink JHG, Koonin EV, Beisel CL, van der Oost J. The miniature CRISPR-Cas12m effector binds DNA to block transcription. Mol Cell 2022; 82:4487-4502.e7. [PMID: 36427491 DOI: 10.1016/j.molcel.2022.11.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 08/01/2022] [Accepted: 10/31/2022] [Indexed: 11/27/2022]
Abstract
CRISPR-Cas are prokaryotic adaptive immune systems. Cas nucleases generally use CRISPR-derived RNA guides to specifically bind and cleave DNA or RNA targets. Here, we describe the experimental characterization of a bacterial CRISPR effector protein Cas12m representing subtype V-M. Despite being less than half the size of Cas12a, Cas12m catalyzes auto-processing of a crRNA guide, recognizes a 5'-TTN' protospacer-adjacent motif (PAM), and stably binds a guide-complementary double-stranded DNA (dsDNA). Cas12m has a RuvC domain with a non-canonical catalytic site and accordingly is incapable of guide-dependent cleavage of target nucleic acids. Despite lacking target cleavage activity, the high binding affinity of Cas12m to dsDNA targets allows for interference as demonstrated by its ability to protect bacteria against invading plasmids through silencing invader transcription and/or replication. Based on these molecular features, we repurposed Cas12m by fusing it to a cytidine deaminase that resulted in base editing within a distinct window.
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Affiliation(s)
- Wen Y Wu
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands.
| | - Prarthana Mohanraju
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Chunyu Liao
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Belén Adiego-Pérez
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Sjoerd C A Creutzburg
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Kira S Makarova
- National Centre for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Karlijn Keessen
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Timon A Lindeboom
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Tahseen S Khan
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Stijn Prinsen
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Rob Joosten
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | | | - Anzhela Migur
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Charlie Laffeber
- Department of Molecular Genetics, Oncode Institute, Erasmus MC Cancer Institute, Erasmus University Medical Center, 3000 CA Rotterdam, the Netherlands
| | | | - Joyce H G Lebbink
- Department of Molecular Genetics, Oncode Institute, Erasmus MC Cancer Institute, Erasmus University Medical Center, 3000 CA Rotterdam, the Netherlands; Department of Radiation Oncology, Erasmus University Medical Center, 3000 CA Rotterdam, the Netherlands
| | - Eugene V Koonin
- National Centre for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - 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
| | - John van der Oost
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands.
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28
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Bravo JP, Hibshman GN, Taylor DW. Constructing next-generation CRISPR-Cas tools from structural blueprints. Curr Opin Biotechnol 2022; 78:102839. [PMID: 36371895 DOI: 10.1016/j.copbio.2022.102839] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 09/18/2022] [Accepted: 10/10/2022] [Indexed: 11/12/2022]
Abstract
Clustered regularly interspaced short palindromic repeats - CRISPR-associated protein (CRISPR-Cas) systems are a critical component of the bacterial adaptive immune response. Since the discovery that they can be reengineered as programmable RNA-guided nucleases, there has been significant interest in using these systems to perform diverse and precise genetic manipulations. Here, we outline recent advances in the mechanistic understanding of CRISPR-Cas9, how these findings have been leveraged in the rational redesign of Cas9 variants with altered activities, and how these novel tools can be exploited for biotechnology and therapeutics. We also discuss the potential of the ubiquitous, yet often-overlooked, multisubunit CRISPR effector complexes for large-scale genomic deletions. Furthermore, we highlight how future structural studies will bolster these technologies.
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Affiliation(s)
- Jack Pk Bravo
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA.
| | - Grace N Hibshman
- Interdisciplinary Life Sciences Graduate Program, The University of Texas at Austin, Austin, TX, USA
| | - David W Taylor
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA; Interdisciplinary Life Sciences Graduate Program, The University of Texas at Austin, Austin, TX, USA; Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX, USA; Livestrong Cancer Institutes, Dell Medical School, Austin, TX, USA
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29
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Borišek J, Aupič J, Magistrato A. Establishing the catalytic and regulatory mechanism of
RNA
‐based machineries. WIRES COMPUTATIONAL MOLECULAR SCIENCE 2022. [DOI: 10.1002/wcms.1643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Jure Borišek
- Theory Department National Institute of Chemistry Ljubljana Slovenia
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30
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Abstract
At the core of the CRISPR-Cas9 genome-editing technology, the endonuclease Cas9 introduces site-specific breaks in DNA. However, precise mechanistic information to ameliorating Cas9 function is still missing. Here, multi-microsecond molecular dynamics, free-energy and multiscale simulations are combined with solution NMR and DNA cleavage experiments to resolve the catalytic mechanism of target DNA cleavage. We show that the conformation of an active HNH nuclease is tightly dependent on the catalytic Mg2+, unveiling its cardinal structural role. This activated Mg2+-bound HNH is consistently described through molecular simulations, solution NMR and DNA cleavage assays, revealing also that the protonation state of the catalytic H840 is strongly affected by active site mutations. Finally, ab-initio QM(DFT)/MM simulations and metadynamics establish the catalytic mechanism, showing that the catalysis is activated by H840 and completed by K866, rationalising DNA cleavage experiments. This information is critical to enhance the enzymatic function of CRISPR-Cas9 toward improved genome-editing.
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31
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Pacesa M, Loeff L, Querques I, Muckenfuss LM, Sawicka M, Jinek M. R-loop formation and conformational activation mechanisms of Cas9. Nature 2022; 609:191-196. [PMID: 36002571 PMCID: PMC9433323 DOI: 10.1038/s41586-022-05114-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 07/14/2022] [Indexed: 12/25/2022]
Abstract
Cas9 is a CRISPR-associated endonuclease capable of RNA-guided, site-specific DNA cleavage1-3. The programmable activity of Cas9 has been widely utilized for genome editing applications4-6, yet its precise mechanisms of target DNA binding and off-target discrimination remain incompletely understood. Here we report a series of cryo-electron microscopy structures of Streptococcus pyogenes Cas9 capturing the directional process of target DNA hybridization. In the early phase of R-loop formation, the Cas9 REC2 and REC3 domains form a positively charged cleft that accommodates the distal end of the target DNA duplex. Guide-target hybridization past the seed region induces rearrangements of the REC2 and REC3 domains and relocation of the HNH nuclease domain to assume a catalytically incompetent checkpoint conformation. Completion of the guide-target heteroduplex triggers conformational activation of the HNH nuclease domain, enabled by distortion of the guide-target heteroduplex, and complementary REC2 and REC3 domain rearrangements. Together, these results establish a structural framework for target DNA-dependent activation of Cas9 that sheds light on its conformational checkpoint mechanism and may facilitate the development of novel Cas9 variants and guide RNA designs with enhanced specificity and activity.
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Affiliation(s)
- Martin Pacesa
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Luuk Loeff
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Irma Querques
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Lena M Muckenfuss
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Marta Sawicka
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Martin Jinek
- Department of Biochemistry, University of Zurich, Zurich, Switzerland.
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32
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Vora DS, Verma Y, Sundar D. A Machine Learning Approach to Identify the Importance of Novel Features for CRISPR/Cas9 Activity Prediction. Biomolecules 2022; 12:1123. [PMID: 36009017 PMCID: PMC9405635 DOI: 10.3390/biom12081123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/08/2022] [Accepted: 08/10/2022] [Indexed: 11/23/2022] Open
Abstract
The reprogrammable CRISPR/Cas9 genome editing tool's growing popularity is hindered by unwanted off-target effects. Efforts have been directed toward designing efficient guide RNAs as well as identifying potential off-target threats, yet factors that determine efficiency and off-target activity remain obscure. Based on sequence features, previous machine learning models performed poorly on new datasets, thus there is a need for the incorporation of novel features. The binding energy estimation of the gRNA-DNA hybrid as well as the Cas9-gRNA-DNA hybrid allowed generating better performing machine learning models for the prediction of Cas9 activity. The analysis of feature contribution towards the model output on a limited dataset indicated that energy features played a determining role along with the sequence features. The binding energy features proved essential for the prediction of on-target activity and off-target sites. The plateau, in the performance on unseen datasets, of current machine learning models could be overcome by incorporating novel features, such as binding energy, among others. The models are provided on GitHub (GitHub Inc., San Francisco, CA, USA).
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Affiliation(s)
- Dhvani Sandip Vora
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Yugesh Verma
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Durai Sundar
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
- Yardi School of Artificial Intelligence, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
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33
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Mahdizadeh SJ, Pålsson E, Carlesso A, Chevet E, Eriksson LA. QM/MM Well-Tempered Metadynamics Study of the Mechanism of XBP1 mRNA Cleavage by Inositol Requiring Enzyme 1α RNase. J Chem Inf Model 2022; 62:4247-4260. [PMID: 35960929 PMCID: PMC9472280 DOI: 10.1021/acs.jcim.2c00735] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A range of in silico methodologies were herein employed to study the unconventional XBP1 mRNA cleavage mechanism performed by the unfolded protein response (UPR) mediator Inositol Requiring Enzyme 1α (IRE1). Using Protein-RNA molecular docking along with a series of extensive restrained/unrestrained atomistic molecular dynamics (MD) simulations, the dynamical behavior of the system was evaluated and a reliable model of the IRE1/XBP1 mRNA complex was constructed. From a series of well-converged quantum mechanics molecular mechanics well-tempered metadynamics (QM/MM WT-MetaD) simulations using the Grimme dispersion interaction corrected semiempirical parametrization method 6 level of theory (PM6-D3) and the AMBER14SB-OL3 force field, the free energy profile of the cleavage mechanism was determined, along with intermediates and transition state structures. The results show two distinct reaction paths based on general acid-general base type mechanisms, with different activation energies that perfectly match observations from experimental mutagenesis data. The study brings unique atomistic insights into the cleavage mechanism of XBP1 mRNA by IRE1 and clarifies the roles of the catalytic residues H910 and Y892. Increased understanding of the details in UPR signaling can assist in the development of new therapeutic agents for its modulation.
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Affiliation(s)
- Sayyed Jalil Mahdizadeh
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden
| | - Emil Pålsson
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden
| | - Antonio Carlesso
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden.,Faculty of Biomedical Sciences, Euler Institute, Università della Svizzera Italiana (USI),, Lugano 6904, Switzerland.,Department of Pharmacology, Sahlgrenska Academy, University of Gothenburg, 405 30 Göteborg, Sweden
| | - Eric Chevet
- INSERM U1242, University of Rennes 1, 35000 Rennes, France.,Centre Eugène Marquis, 35000 Rennes, France
| | - Leif A Eriksson
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden
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34
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Panda G, Ray A. Decrypting the mechanistic basis of CRISPR/Cas9 protein. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2022; 172:60-76. [PMID: 35577099 DOI: 10.1016/j.pbiomolbio.2022.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 04/14/2022] [Accepted: 05/10/2022] [Indexed: 12/25/2022]
Abstract
CRISPR/Cas system, a newly but extensively investigated genome-editing method, harbors practical solutions for various genetic problems. It relies on short guide RNAs (gRNAs) to recruit the Cas9 protein, a DNA cleaving enzyme, to its genomic target DNAs. The Cas9 enzyme exhibits some unique properties, like the ability to differentiate self vs. non-self - DNA strands using the base-pairing potential of crRNA, i.e., only CRISPR DNA is entirely complementary to the CRISPR repeat sequences at the crRNA whereas the presence of mismatches in the upstream region of the spacer permit CRISPR interference which is inhibited in case of CRISPR-DNA, allosteric regulation in its domains, and domain reorientation on sgRNA binding. Several groups have contributed their efforts in understanding the functioning of the CRISPR/Cas system, but even then, there is a lot more to explore in this area. The structural and sequence-based understanding of the whole CRISPR-associated bacterial ortholog family landscape is still ambiguous. A better understanding of the underlying energetics of the CRISPR/Cas9 system should reveal critical parameters to design better CRISPR/Cas9s.
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Affiliation(s)
- Gayatri Panda
- Department of Computational Biology, Indraprastha Institute of Information Technology, New Delhi, India
| | - Arjun Ray
- Department of Computational Biology, Indraprastha Institute of Information Technology, New Delhi, India.
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35
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Rossetti M, Merlo R, Bagheri N, Moscone D, Valenti A, Saha A, Arantes PR, Ippodrino R, Ricci F, Treglia I, Delibato E, van der Oost J, Palermo G, Perugino G, Porchetta A. Enhancement of CRISPR/Cas12a trans-cleavage activity using hairpin DNA reporters. Nucleic Acids Res 2022; 50:8377-8391. [PMID: 35822842 PMCID: PMC9371913 DOI: 10.1093/nar/gkac578] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 06/15/2022] [Accepted: 06/22/2022] [Indexed: 12/24/2022] Open
Abstract
The RNA programmed non-specific (trans) nuclease activity of CRISPR-Cas Type V and VI systems has opened a new era in the field of nucleic acid-based detection. Here, we report on the enhancement of trans-cleavage activity of Cas12a enzymes using hairpin DNA sequences as FRET-based reporters. We discover faster rate of trans-cleavage activity of Cas12a due to its improved affinity (Km) for hairpin DNA structures, and provide mechanistic insights of our findings through Molecular Dynamics simulations. Using hairpin DNA probes we significantly enhance FRET-based signal transduction compared to the widely used linear single stranded DNA reporters. Our signal transduction enables faster detection of clinically relevant double stranded DNA targets with improved sensitivity and specificity either in the presence or in the absence of an upstream pre-amplification step.
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Affiliation(s)
- Marianna Rossetti
- Department of Chemistry, University of Rome, Tor Vergata, Via della Ricerca Scientifica 00133, Rome, Italy
| | - Rosa Merlo
- Institute of Biosciences and BioResources, National Research Council of Italy, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Neda Bagheri
- Department of Chemistry, University of Rome, Tor Vergata, Via della Ricerca Scientifica 00133, Rome, Italy
| | - Danila Moscone
- Department of Chemistry, University of Rome, Tor Vergata, Via della Ricerca Scientifica 00133, Rome, Italy
| | - Anna Valenti
- Institute of Biosciences and BioResources, National Research Council of Italy, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Aakash Saha
- Department of Bioengineering and Department of Chemistry, University of California Riverside, 900 University Avenue, Riverside, CA 52512 USA
| | - Pablo R Arantes
- Department of Bioengineering and Department of Chemistry, University of California Riverside, 900 University Avenue, Riverside, CA 52512 USA
| | - Rudy Ippodrino
- Ulisse BioMed S.r.l. Area Science Park, 34149 Trieste, Italy
| | - Francesco Ricci
- Department of Chemistry, University of Rome, Tor Vergata, Via della Ricerca Scientifica 00133, Rome, Italy
| | - Ida Treglia
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome, Italy
| | - Elisabetta Delibato
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome, Italy
| | - John van der Oost
- Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Giulia Palermo
- Department of Bioengineering and Department of Chemistry, University of California Riverside, 900 University Avenue, Riverside, CA 52512 USA
| | - Giuseppe Perugino
- Institute of Biosciences and BioResources, National Research Council of Italy, Via Pietro Castellino 111, 80131 Naples, Italy.,Department of Biology, University of Naples "Federico II", Complesso Universitario di Monte Sant'Angelo, Ed. 7, Via Cintia 26, 80126 Naples, Italy
| | - Alessandro Porchetta
- Department of Chemistry, University of Rome, Tor Vergata, Via della Ricerca Scientifica 00133, Rome, Italy
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36
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Talluri S. Engineering and Design of Programmable Genome Editors. J Phys Chem B 2022; 126:5140-5150. [PMID: 35819243 DOI: 10.1021/acs.jpcb.2c03761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Programmable genome editors are enzymes that can be targeted to a specific location in the genome for making site-specific alterations or deletions. The engineering, design, and development of sequence-specific editors has resulted in a dramatic increase in the precision of editing for nucleotide sequences. These editors can target specific locations in a genome, in vivo. The genome editors are being deployed for the development of genetically modified organisms for agriculture and industry, and for gene therapy of inherited human genetic disorders, cancer, and immunotherapy. Experimental and computational studies of structure, binding, activity, dynamics, and folding, reviewed here, have provided valuable insights that have the potential for increasing the functional efficiency of these gene/genome editors. Biochemical and biophysical studies of the specificities of natural and engineered genome editors reveal that increased binding affinity can be detrimental because of the increase of off-target effects and that the engineering and design of genome editors with higher specificity may require modulation and control of the conformational dynamics.
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Affiliation(s)
- Sekhar Talluri
- Department of Biotechnology, GITAM, Visakhapatnam, India 530045
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37
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Saha A, Arantes PR, Palermo G. Dynamics and mechanisms of CRISPR-Cas9 through the lens of computational methods. Curr Opin Struct Biol 2022; 75:102400. [PMID: 35689914 DOI: 10.1016/j.sbi.2022.102400] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 04/25/2022] [Accepted: 05/07/2022] [Indexed: 12/24/2022]
Abstract
The clustered regularly interspaced short palindromic repeat (CRISPR) genome-editing revolution established the beginning of a new era in life sciences. Here, we review the role of state-of-the-art computations in the CRISPR-Cas9 revolution, from the early refinement of cryo-EM data to enhanced simulations of large-scale conformational transitions. Molecular simulations reported a mechanism for RNA binding and the formation of a catalytically competent Cas9 enzyme, in agreement with subsequent structural studies. Inspired by single-molecule experiments, molecular dynamics offered a rationale for the onset of off-target effects, while graph theory unveiled the allosteric regulation. Finally, the use of a mixed quantum-classical approach established the catalytic mechanism of DNA cleavage. Overall, molecular simulations have been instrumental in understanding the dynamics and mechanism of CRISPR-Cas9, contributing to understanding function, catalysis, allostery, and specificity.
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Affiliation(s)
- Aakash Saha
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA, 52512, United States. https://twitter.com/@aakashsahha
| | - Pablo R Arantes
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA, 52512, United States. https://twitter.com/@pablitoarantes
| | - Giulia Palermo
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA, 52512, United States; Department of Chemistry, University of California Riverside, 900 University Avenue, Riverside, CA, 52512, United States.
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38
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Structural and Functional Characterization of the Holliday Junction Resolvase RuvC from Deinococcus radiodurans. Microorganisms 2022; 10:microorganisms10061160. [PMID: 35744678 PMCID: PMC9228767 DOI: 10.3390/microorganisms10061160] [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] [Received: 04/21/2022] [Revised: 05/24/2022] [Accepted: 06/02/2022] [Indexed: 12/04/2022] Open
Abstract
Holliday junctions (HJs) are four-way DNA structures, which are an important intermediate in the process of homologous recombination. In most bacteria, HJs are cleaved by specific nucleases called RuvC resolvases at the end of homologous recombination. Deinococcus radiodurans is an extraordinary radiation-resistant bacterium and is known as an ideal model organism for elucidating DNA repair processes. Here, we described the biochemical properties and the crystal structure of RuvC from D. radiodurans (DrRuvC). DrRuvC exhibited an RNase H fold that belonged to the retroviral integrase family. Among many DNA substrates, DrRuvC specifically bound to HJ DNA and cleaved it. In particular, Mn2+ was the preferred bivalent metal co-factor for HJ cleavage, whereas high concentrations of Mg2+ inhibited the binding of DrRuvC to HJ. In addition, DrRuvC was crystallized and the crystals diffracted to 1.6 Å. The crystal structure of DrRuvC revealed essential amino acid sites for cleavage and binding activities, indicating that DrRuvC was a typical resolvase with a characteristic choice for metal co-factor.
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39
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Pan X, Van R, Epifanovsky E, Liu J, Pu J, Nam K, Shao Y. Accelerating Ab Initio Quantum Mechanical and Molecular Mechanical (QM/MM) Molecular Dynamics Simulations with Multiple Time Step Integration and a Recalibrated Semiempirical QM/MM Hamiltonian. J Phys Chem B 2022; 126:10.1021/acs.jpcb.2c02262. [PMID: 35653199 PMCID: PMC9715852 DOI: 10.1021/acs.jpcb.2c02262] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Molecular dynamics (MD) simulations employing ab initio quantum mechanical and molecular mechanical (ai-QM/MM) potentials are considered to be the state of the art, but the high computational cost associated with the ai-QM calculations remains a theoretical challenge for their routine application. Here, we present a modified protocol of the multiple time step (MTS) method for accelerating ai-QM/MM MD simulations of condensed-phase reactions. Within a previous MTS protocol [Nam J. Chem. Theory Comput. 2014, 10, 4175], reference forces are evaluated using a low-level (semiempirical QM/MM) Hamiltonian and employed at inner time steps to propagate the nuclear motions. Correction forces, which arise from the force differences between high-level (ai-QM/MM) and low-level Hamiltonians, are applied at outer time steps, where the MTS algorithm allows the time-reversible integration of the correction forces. To increase the outer step size, which is bound by the highest-frequency component in the correction forces, the semiempirical QM Hamiltonian is recalibrated in this work to minimize the magnitude of the correction forces. The remaining high-frequency modes, which are mainly bond stretches involving hydrogen atoms, are then removed from the correction forces. When combined with a Langevin or SIN(R) thermostat, the modified MTS-QM/MM scheme remains robust with an up to 8 (with Langevin) or 10 fs (with SIN(R)) outer time step (with 1 fs inner time steps) for the chorismate mutase system. This leads to an over 5-fold speedup over standard ai-QM/MM simulations, without sacrificing the accuracy in the predicted free energy profile of the reaction.
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Affiliation(s)
- Xiaoliang Pan
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019-5251, United States
| | - Richard Van
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019-5251, United States
| | - Evgeny Epifanovsky
- Q-Chem, Inc., 6601 Owens Drive, Suite 105, Pleasanton, California 94588, United States
| | - Jian Liu
- Beijing National Laboratory for Molecular Sciences, Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Jingzhi Pu
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, 402 N Blackford St., LD326, Indianapolis, Indiana 46202, United States
| | - Kwangho Nam
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, Texas 76019, United States
| | - Yihan Shao
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019-5251, United States
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40
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Aranda J, Wieczór M, Terrazas M, Brun-Heath I, Orozco M. Mechanism of reaction of RNA-dependent RNA polymerase from SARS-CoV-2. CHEM CATALYSIS 2022; 2:1084-1099. [PMID: 35465139 PMCID: PMC9016896 DOI: 10.1016/j.checat.2022.03.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 03/08/2022] [Accepted: 03/24/2022] [Indexed: 01/21/2023]
Abstract
We combine molecular dynamics, statistical mechanics, and hybrid quantum mechanics/molecular mechanics simulations to describe mechanistically the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA-dependent RNA polymerase (RdRp). Our study analyzes the binding mode of both natural triphosphate substrates as well as remdesivir triphosphate (the active form of drug), which is bound preferentially over ATP by RdRp while being poorly recognized by human RNA polymerase II (RNA Pol II). A comparison of incorporation rates between natural and antiviral nucleotides shows that remdesivir is incorporated more slowly into the nascent RNA compared with ATP, leading to an RNA duplex that is structurally very similar to an unmodified one, arguing against the hypothesis that remdesivir is a competitive inhibitor of ATP. We characterize the entire mechanism of reaction, finding that viral RdRp is highly processive and displays a higher catalytic rate of incorporation than human RNA Pol II. Overall, our study provides the first detailed explanation of the replication mechanism of RdRp.
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Affiliation(s)
- Juan Aranda
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Milosz Wieczór
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain
- Department of Physical Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Montserrat Terrazas
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain
- Department of Inorganic and Organic Chemistry, Section of Organic Chemistry, IBUB, University of Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Isabelle Brun-Heath
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Modesto Orozco
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, 08028 Barcelona, Spain
- Departament de Bioquímica i Biomedicine, Universitat de Barcelona, Universitat de Barcelona, Avinguda Diagonal 645, 08028 Barcelona, Spain
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41
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Wang J, Skeens E, Arantes PR, Maschietto F, Allen B, Kyro GW, Lisi GP, Palermo G, Batista VS. Structural Basis for Reduced Dynamics of Three Engineered HNH Endonuclease Lys-to-Ala Mutants for the Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)-Associated 9 (CRISPR/Cas9) Enzyme. Biochemistry 2022; 61:785-794. [PMID: 35420793 DOI: 10.1021/acs.biochem.2c00127] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Many bacteria possess type-II immunity against invading phages or plasmids known as the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated 9 (Cas9) system to detect and degrade the foreign DNA sequences. The Cas9 protein has two endonucleases responsible for double-strand breaks (the HNH domain for cleaving the target strand of DNA duplexes and RuvC domain for the nontarget strand, respectively) and a single-guide RNA-binding domain where the RNA and target DNA strands are base-paired. Three engineered single Lys-to-Ala HNH mutants (K810A, K848A, and K855A) exhibit an enhanced substrate specificity for cleavage of the target DNA strand. We report in this study that in the wild-type (wt) enzyme, D835, Y836, and D837 within the Y836-containing loop (comprising E827-D837) adjacent to the catalytic site have uncharacterizable broadened 1H15N nuclear magnetic resonance (NMR) features, whereas remaining residues in the loop have different extents of broadened NMR spectra. We find that this loop in the wt enzyme exhibits three distinct conformations over the duration of the molecular dynamics simulations, whereas the three Lys-to-Ala mutants retain only one conformation. The versatility of multiple alternate conformations of this loop in the wt enzyme could help to recruit noncognate DNA substrates into the HNH active site for cleavage, thereby reducing its substrate specificity relative to the three mutants. Our study provides further experimental and computational evidence that Lys-to-Ala substitutions reduce dynamics of proteins and thus increase their stability.
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Affiliation(s)
- Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8114, United States
| | - Erin Skeens
- Department of Molecular and Cell Biology and Biochemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Pablo R Arantes
- Department of Bioengineering and Department of Chemistry, University of California Riverside, Riverside, California 92521-9800, United States
| | - Federica Maschietto
- Department of Chemistry, Yale University, New Haven, Connecticut 06511-8499, United States
| | - Brandon Allen
- Department of Chemistry, Yale University, New Haven, Connecticut 06511-8499, United States
| | - Gregory W Kyro
- Department of Chemistry, Yale University, New Haven, Connecticut 06511-8499, United States
| | - George P Lisi
- Department of Molecular and Cell Biology and Biochemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Giulia Palermo
- Department of Bioengineering and Department of Chemistry, University of California Riverside, Riverside, California 92521-9800, United States
| | - Victor S Batista
- Department of Chemistry, Yale University, New Haven, Connecticut 06511-8499, United States
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42
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Bravo JPK, Liu MS, Hibshman GN, Dangerfield TL, Jung K, McCool RS, Johnson KA, Taylor DW. Structural basis for mismatch surveillance by CRISPR–Cas9. Nature 2022. [DOI: 10.1038/s41586-022-04470-1 (2022)] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
AbstractCRISPR–Cas9 as a programmable genome editing tool is hindered by off-target DNA cleavage1–4, and the underlying mechanisms by which Cas9 recognizes mismatches are poorly understood5–7. Although Cas9 variants with greater discrimination against mismatches have been designed8–10, these suffer from substantially reduced rates of on-target DNA cleavage5,11. Here we used kinetics-guided cryo-electron microscopy to determine the structure of Cas9 at different stages of mismatch cleavage. We observed a distinct, linear conformation of the guide RNA–DNA duplex formed in the presence of mismatches, which prevents Cas9 activation. Although the canonical kinked guide RNA–DNA duplex conformation facilitates DNA cleavage, we observe that substrates that contain mismatches distal to the protospacer adjacent motif are stabilized by reorganization of a loop in the RuvC domain. Mutagenesis of mismatch-stabilizing residues reduces off-target DNA cleavage but maintains rapid on-target DNA cleavage. By targeting regions that are exclusively involved in mismatch tolerance, we provide a proof of concept for the design of next-generation high-fidelity Cas9 variants.
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43
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Bravo JPK, Liu MS, Hibshman GN, Dangerfield TL, Jung K, McCool RS, Johnson KA, Taylor DW. Structural basis for mismatch surveillance by CRISPR-Cas9. Nature 2022; 603:343-347. [PMID: 35236982 PMCID: PMC8907077 DOI: 10.1038/s41586-022-04470-1] [Citation(s) in RCA: 110] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 01/25/2022] [Indexed: 11/09/2022]
Abstract
CRISPR-Cas9 as a programmable genome editing tool is hindered by off-target DNA cleavage1-4, and the underlying mechanisms by which Cas9 recognizes mismatches are poorly understood5-7. Although Cas9 variants with greater discrimination against mismatches have been designed8-10, these suffer from substantially reduced rates of on-target DNA cleavage5,11. Here we used kinetics-guided cryo-electron microscopy to determine the structure of Cas9 at different stages of mismatch cleavage. We observed a distinct, linear conformation of the guide RNA-DNA duplex formed in the presence of mismatches, which prevents Cas9 activation. Although the canonical kinked guide RNA-DNA duplex conformation facilitates DNA cleavage, we observe that substrates that contain mismatches distal to the protospacer adjacent motif are stabilized by reorganization of a loop in the RuvC domain. Mutagenesis of mismatch-stabilizing residues reduces off-target DNA cleavage but maintains rapid on-target DNA cleavage. By targeting regions that are exclusively involved in mismatch tolerance, we provide a proof of concept for the design of next-generation high-fidelity Cas9 variants.
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Affiliation(s)
- Jack P K Bravo
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | - Mu-Sen Liu
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | - Grace N Hibshman
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX, USA
| | - Tyler L Dangerfield
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX, USA
| | - Kyungseok Jung
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | - Ryan S McCool
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX, USA
| | - Kenneth A Johnson
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA.
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX, USA.
| | - David W Taylor
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA.
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX, USA.
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX, USA.
- Livestrong Cancer Institutes, Dell Medical School, University of Texas at Austin, Austin, TX, USA.
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Brémond É, Savarese M, Rega N, Ciofini I, Adamo C. Free Energy Profiles of Proton Transfer Reactions: Density Functional Benchmark from Biased Ab Initio Dynamics. J Chem Theory Comput 2022; 18:1501-1511. [PMID: 35129987 DOI: 10.1021/acs.jctc.1c01002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
By coupling an enhanced sampling algorithm with an orbital-localized variant of Car-Parrinello molecular dynamics, the so-called atomic centered density matrix propagation model, we reconstruct the free energy profiles along reaction pathways using different density functional approximations (DFAs) ranging from locals to hybrids. In particular, we compare the computed free energy barrier height of proton transfer (PT) reactions to those obtained by a more traditional static approach, based on the intrinsic reaction coordinate (IRC), for two case systems, namely malonaldehyde and formic acid dimer. The obtained results show that both the IRC profiles and the potentials of mean force, derived from biased dynamic trajectories, are very sensitive to the density functional approximation applied. More precisely, we observe that, with the notable exception of M06-L, local density functionals always strongly underestimate the reaction barrier heights. More generally, we find that also the shape of the free energy profile is very sensitive to the density functional choice, thus highlighting the effect, often neglected, that the choice of DFA has also in the case of dynamics simulations.
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Affiliation(s)
- Éric Brémond
- Université de Paris, ITODYS, CNRS, F-75006 Paris, France
| | - Marika Savarese
- Chimie ParisTech-PSL, CNRS, Institute of Chemistry for Health and Life Sciences, F-75005 Paris, France
| | - Nadia Rega
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario di M.S. Angelo, via Cintia, I-80126 Napoli, Italy.,Scuola Superiore Meridionale, Largo S. Marcellino 10, I-80138 Napoli, Italy.,Centro Interdipartimentale di Ricerca sui Biomateriali (CRIB), Piazzale Tecchio 80, I-80125, Napoli, Italy
| | - Ilaria Ciofini
- Chimie ParisTech-PSL, CNRS, Institute of Chemistry for Health and Life Sciences, F-75005 Paris, France
| | - Carlo Adamo
- Chimie ParisTech-PSL, CNRS, Institute of Chemistry for Health and Life Sciences, F-75005 Paris, France.,Institut Universitaire de France, 103 Boulevard Saint Michel, F-75005 Paris, France
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45
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Emerging Methods and Applications to Decrypt Allostery in Proteins and Nucleic Acids. J Mol Biol 2022; 434:167518. [DOI: 10.1016/j.jmb.2022.167518] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 02/11/2022] [Accepted: 02/23/2022] [Indexed: 11/19/2022]
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46
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Wang J, Arantes PR, Ahsan M, Sinha S, Kyro GW, Maschietto F, Allen B, Skeens E, Lisi GP, Batista VS, Palermo G. Twisting and swiveling domain motions in Cas9 to recognize target DNA duplexes, make double-strand breaks, and release cleaved duplexes. Front Mol Biosci 2022; 9:1072733. [PMID: 36699705 PMCID: PMC9868570 DOI: 10.3389/fmolb.2022.1072733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 12/12/2022] [Indexed: 01/11/2023] Open
Abstract
The CRISPR-associated protein 9 (Cas9) has been engineered as a precise gene editing tool to make double-strand breaks. CRISPR-associated protein 9 binds the folded guide RNA (gRNA) that serves as a binding scaffold to guide it to the target DNA duplex via a RecA-like strand-displacement mechanism but without ATP binding or hydrolysis. The target search begins with the protospacer adjacent motif or PAM-interacting domain, recognizing it at the major groove of the duplex and melting its downstream duplex where an RNA-DNA heteroduplex is formed at nanomolar affinity. The rate-limiting step is the formation of an R-loop structure where the HNH domain inserts between the target heteroduplex and the displaced non-target DNA strand. Once the R-loop structure is formed, the non-target strand is rapidly cleaved by RuvC and ejected from the active site. This event is immediately followed by cleavage of the target DNA strand by the HNH domain and product release. Within CRISPR-associated protein 9, the HNH domain is inserted into the RuvC domain near the RuvC active site via two linker loops that provide allosteric communication between the two active sites. Due to the high flexibility of these loops and active sites, biophysical techniques have been instrumental in characterizing the dynamics and mechanism of the CRISPR-associated protein 9 nucleases, aiding structural studies in the visualization of the complete active sites and relevant linker structures. Here, we review biochemical, structural, and biophysical studies on the underlying mechanism with emphasis on how CRISPR-associated protein 9 selects the target DNA duplex and rejects non-target sequences.
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Affiliation(s)
- Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
| | - Pablo R Arantes
- Department of Bioengineering and Department of Chemistry, University of California, Riverside, Riverside, CA, United States
| | - Mohd Ahsan
- Department of Bioengineering and Department of Chemistry, University of California, Riverside, Riverside, CA, United States
| | - Souvik Sinha
- Department of Bioengineering and Department of Chemistry, University of California, Riverside, Riverside, CA, United States
| | - Gregory W Kyro
- Department of Chemistry, Yale University, New Haven, CT, United States
| | | | - Brandon Allen
- Department of Chemistry, Yale University, New Haven, CT, United States
| | - Erin Skeens
- Department of Molecular and Cell Biology and Biochemistry, Brown University, Providence, RI, United States
| | - George P Lisi
- Department of Molecular and Cell Biology and Biochemistry, Brown University, Providence, RI, United States
| | - Victor S Batista
- Department of Chemistry, Yale University, New Haven, CT, United States
| | - Giulia Palermo
- Department of Bioengineering and Department of Chemistry, University of California, Riverside, Riverside, CA, United States
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Abstract
:
Clustered regularly interspaced short palindromic repeats along with CRISPR-associated protein
mechanisms preserve the memory of previous experiences with DNA invaders, in particular spacers
that are embedded in CRISPR arrays between coordinate repeats. There has been a fast progression in
the comprehension of this immune system and its implementations; however, there are numerous points
of view that anticipate explanations to make the field an energetic research zone. The efficiency of
CRISPR-Cas depends upon well-considered single guide RNA; for this purpose, many bioinformatics
methods and tools are created to support the design of greatly active and precise single guide RNA. Insilico
single guide RNA architecture is a crucial point for effective gene editing by means of the
CRISPR technique. Persistent attempts have been made to improve in-silico single guide RNA formulation
having great on-target effectiveness and decreased off-target effects. This review offers a summary
of the CRISPR computational tools to help different researchers pick a specific tool for their work according
to pros and cons, along with new thoughts to make new computational tools to overcome all existing
limitations.
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Affiliation(s)
- Mohsin Ali Nasir
- Center for Informational Biology, University of Electronic Science and Technology of China, No. 2006, Xiyuan Ave,
West Hi-Tech Zone, Chengdu 611731, China
| | - Samia Nawaz
- Center for Informational Biology, University of Electronic Science and Technology of China, No. 2006, Xiyuan Ave,
West Hi-Tech Zone, Chengdu 611731, China
| | - Jian Huang
- Center for Informational Biology, University of Electronic Science and Technology of China, No. 2006, Xiyuan Ave,
West Hi-Tech Zone, Chengdu 611731, China
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48
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Babu K, Kathiresan V, Kumari P, Newsom S, Parameshwaran HP, Chen X, Liu J, Qin PZ, Rajan R. Coordinated Actions of Cas9 HNH and RuvC Nuclease Domains Are Regulated by the Bridge Helix and the Target DNA Sequence. Biochemistry 2021; 60:3783-3800. [PMID: 34757726 PMCID: PMC8675354 DOI: 10.1021/acs.biochem.1c00354] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 10/23/2021] [Indexed: 12/22/2022]
Abstract
CRISPR-Cas systems are RNA-guided nucleases that provide adaptive immune protection in bacteria and archaea against intruding genomic materials. Cas9, a type-II CRISPR effector protein, is widely used for gene editing applications since a single guide RNA can direct Cas9 to cleave specific genomic targets. The conformational changes associated with RNA/DNA binding are being modulated to develop Cas9 variants with reduced off-target cleavage. Previously, we showed that proline substitutions in the arginine-rich bridge helix (BH) of Streptococcus pyogenes Cas9 (SpyCas9-L64P-K65P, SpyCas92Pro) improve target DNA cleavage selectivity. In this study, we establish that kinetic analysis of the cleavage of supercoiled plasmid substrates provides a facile means to analyze the use of two parallel routes for DNA linearization by SpyCas9: (i) nicking by HNH followed by RuvC cleavage (the TS (target strand) pathway) and (ii) nicking by RuvC followed by HNH cleavage (the NTS (nontarget strand) pathway). BH substitutions and DNA mismatches alter the individual rate constants, resulting in changes in the relative use of the two pathways and the production of nicked and linear species within a given pathway. The results reveal coordinated actions between HNH and RuvC to linearize DNA, which is modulated by the integrity of the BH and the position of the mismatch in the substrate, with each condition producing distinct conformational energy landscapes as observed by molecular dynamics simulations. Overall, our results indicate that BH interactions with RNA/DNA enable target DNA discrimination through the differential use of the parallel sequential pathways driven by HNH/RuvC coordination.
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Affiliation(s)
- Kesavan Babu
- Department
of Chemistry and Biochemistry, Price Family Foundation Institute of
Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Venkatesan Kathiresan
- Department
of Chemistry, University of Southern California, 3430 S. Vermont Ave., Los Angeles, California 90089, United States
| | - Pratibha Kumari
- Department
of Pharmaceutical Sciences, University of North Texas System College
of Pharmacy, University of North Texas Health
Science Center, 3500 Camp Bowie Blvd., Fort Worth, Texas 76107, United
States
| | - Sydney Newsom
- Department
of Chemistry and Biochemistry, Price Family Foundation Institute of
Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Hari Priya Parameshwaran
- Department
of Chemistry and Biochemistry, Price Family Foundation Institute of
Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Xiongping Chen
- Department
of Pharmaceutical Sciences, University of North Texas System College
of Pharmacy, University of North Texas Health
Science Center, 3500 Camp Bowie Blvd., Fort Worth, Texas 76107, United
States
| | - Jin Liu
- Department
of Pharmaceutical Sciences, University of North Texas System College
of Pharmacy, University of North Texas Health
Science Center, 3500 Camp Bowie Blvd., Fort Worth, Texas 76107, United
States
| | - Peter Z. Qin
- Department
of Chemistry, University of Southern California, 3430 S. Vermont Ave., Los Angeles, California 90089, United States
| | - Rakhi Rajan
- Department
of Chemistry and Biochemistry, Price Family Foundation Institute of
Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
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49
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Medina FE, Jaña GA. QM/MM Study of a VIM-1 Metallo-β-Lactamase Enzyme: The Catalytic Reaction Mechanism. ACS Catal 2021. [DOI: 10.1021/acscatal.1c04786] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Fabiola E. Medina
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Autopista Concepción-Talcahuano, 7100 Talcahuano, Chile
- Departamento de Química, Facultad de Ciencias, Universidad del Bío-Bío, 4051381 Concepción, Chile
| | - Gonzalo A. Jaña
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Autopista Concepción-Talcahuano, 7100 Talcahuano, Chile
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50
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Wang J, Arantes PR, Bhattarai A, Hsu RV, Pawnikar S, Huang YMM, Palermo G, Miao Y. Gaussian accelerated molecular dynamics (GaMD): principles and applications. WILEY INTERDISCIPLINARY REVIEWS. COMPUTATIONAL MOLECULAR SCIENCE 2021; 11:e1521. [PMID: 34899998 PMCID: PMC8658739 DOI: 10.1002/wcms.1521] [Citation(s) in RCA: 95] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 01/28/2021] [Indexed: 12/20/2022]
Abstract
Gaussian accelerated molecular dynamics (GaMD) is a robust computational method for simultaneous unconstrained enhanced sampling and free energy calculations of biomolecules. It works by adding a harmonic boost potential to smooth biomolecular potential energy surface and reduce energy barriers. GaMD greatly accelerates biomolecular simulations by orders of magnitude. Without the need to set predefined reaction coordinates or collective variables, GaMD provides unconstrained enhanced sampling and is advantageous for simulating complex biological processes. The GaMD boost potential exhibits a Gaussian distribution, thereby allowing for energetic reweighting via cumulant expansion to the second order (i.e., "Gaussian approximation"). This leads to accurate reconstruction of free energy landscapes of biomolecules. Hybrid schemes with other enhanced sampling methods, such as the replica exchange GaMD (rex-GaMD) and replica exchange umbrella sampling GaMD (GaREUS), have also been introduced, further improving sampling and free energy calculations. Recently, new "selective GaMD" algorithms including the ligand GaMD (LiGaMD) and peptide GaMD (Pep-GaMD) enabled microsecond simulations to capture repetitive dissociation and binding of small-molecule ligands and highly flexible peptides. The simulations then allowed highly efficient quantitative characterization of the ligand/peptide binding thermodynamics and kinetics. Taken together, GaMD and its innovative variants are applicable to simulate a wide variety of biomolecular dynamics, including protein folding, conformational changes and allostery, ligand binding, peptide binding, protein-protein/nucleic acid/carbohydrate interactions, and carbohydrate/nucleic acid interactions. In this review, we present principles of the GaMD algorithms and recent applications in biomolecular simulations and drug design.
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Affiliation(s)
- Jinan Wang
- Center for Computational Biology and Department of Molecular Biosciences, University of Kansas, 2030 Becker Dr., Lawrence, KS, 66047, United States
| | - Pablo R Arantes
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA 92512, United States
| | - Apurba Bhattarai
- Center for Computational Biology and Department of Molecular Biosciences, University of Kansas, 2030 Becker Dr, Lawrence, KS, 66047, United States
| | - Rohaine V Hsu
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA 92512, United States
| | - Shristi Pawnikar
- Center for Computational Biology and Department of Molecular Biosciences, University of Kansas, 2030 Becker Dr., Lawrence, KS, 66047, United States
| | - Yu-Ming M Huang
- Department of Physics & Astronomy, Wayne State University, 666 W Hancock St, Detroit, MI 48207, USA
| | - Giulia Palermo
- Department of Bioengineering and Department of Chemistry, University of California Riverside, 900 University Avenue, Riverside, CA 92512, United States
| | - Yinglong Miao
- Center for Computational Biology and Department of Molecular Biosciences, University of Kansas, 2030 Becker Dr., Lawrence, Kansas 66047, United States
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