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Ghadirian N, Morgan RD, Horton NC. DNA Sequence Control of Enzyme Filamentation and Activation of the SgrAI Endonuclease. Biochemistry 2024; 63:326-338. [PMID: 38207281 DOI: 10.1021/acs.biochem.3c00313] [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: 01/13/2024]
Abstract
Enzyme polymerization (also known as filamentation) has emerged as a new layer of enzyme regulation. SgrAI is a sequence-dependent DNA endonuclease that forms polymeric filaments with enhanced DNA cleavage activity as well as altered DNA sequence specificity. To better understand this unusual regulatory mechanism, full global kinetic modeling of the reaction pathway, including the enzyme filamentation steps, has been undertaken. Prior work with the primary DNA recognition sequence cleaved by SgrAI has shown how the kinetic rate constants of each reaction step are tuned to maximize activation and DNA cleavage while minimizing the extent of DNA cleavage to the host genome. In the current work, we expand on our prior study by now including DNA cleavage of a secondary recognition sequence, to understand how the sequence of the bound DNA modulates filamentation and activation of SgrAI. The work shows that an allosteric equilibrium between low and high activity states is modulated by the sequence of bound DNA, with primary sequences more prone to activation and filament formation, while SgrAI bound to secondary recognition sequences favor the low (and nonfilamenting) state by up to 40-fold. In addition, the degree of methylation of secondary sequences in the host organism, Streptomyces griseus, is now reported for the first time and shows that as predicted, these sequences are left unprotected from the SgrAI endonuclease making sequence specificity critical in this unusual filament-forming enzyme.
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Affiliation(s)
- Niloofar Ghadirian
- Department of Chemistry & Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Richard D Morgan
- New England Biolabs, Inc., Ipswich, Massachusetts 01938, United States
| | - Nancy C Horton
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721, United States
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2
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The role of filamentation in activation and DNA sequence specificity of the sequence-specific endonuclease SgrAI. Biochem Soc Trans 2022; 50:1703-1714. [PMID: 36398769 PMCID: PMC9788392 DOI: 10.1042/bst20220547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 10/09/2022] [Accepted: 10/12/2022] [Indexed: 11/19/2022]
Abstract
Filament formation by metabolic, biosynthetic, and other enzymes has recently come into focus as a mechanism to fine-tune enzyme activity in the cell. Filamentation is key to the function of SgrAI, a sequence-specific DNA endonuclease that has served as a model system to provide some of the deepest insights into the biophysical characteristics of filamentation and its functional consequences. Structure-function analyses reveal that, in the filamentous state, SgrAI stabilizes an activated enzyme conformation that leads to accelerated DNA cleavage activity and expanded DNA sequence specificity. The latter is thought to be mediated by sequence-specific DNA structure, protein-DNA interactions, and a disorder-to-order transition in the protein, which collectively affect the relative stabilities of the inactive, non-filamentous conformation and the active, filamentous conformation of SgrAI bound to DNA. Full global kinetic modeling of the DNA cleavage pathway reveals a slow, rate-limiting, second-order association rate constant for filament assembly, and simulations of in vivo activity predict that filamentation is superior to non-filamenting mechanisms in ensuring rapid activation and sequestration of SgrAI's DNA cleavage activity on phage DNA and away from the host chromosome. In vivo studies demonstrate the critical requirement for accelerated DNA cleavage by SgrAI in its biological role to safeguard the bacterial host. Collectively, these data have advanced our understanding of how filamentation can regulate enzyme structure and function, while the experimental strategies used for SgrAI can be applied to other enzymatic systems to identify novel functional roles for filamentation.
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3
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Shan Z, Ghadirian N, Lyumkis D, Horton NC. Pre-Transition State and Apo Structures of the Filament-Forming Enzyme SgrAI Elucidate Mechanisms of Activation and Substrate Specificity. J Biol Chem 2022; 298:101760. [PMID: 35202658 PMCID: PMC8960973 DOI: 10.1016/j.jbc.2022.101760] [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] [Received: 11/11/2021] [Revised: 02/14/2022] [Accepted: 02/16/2022] [Indexed: 12/01/2022] Open
Abstract
Enzyme filamentation is a widespread phenomenon that mediates enzyme regulation and function. For the filament-forming sequence-specific DNA endonuclease SgrAI, the process of filamentation both accelerates its DNA cleavage activity and expands its DNA sequence specificity, thus allowing for many additional DNA sequences to be rapidly cleaved. Both outcomes—the acceleration of DNA cleavage and the expansion of sequence specificity—are proposed to regulate critical processes in bacterial innate immunity. However, the mechanistic bases underlying these events remain unclear. Herein, we describe two new structures of the SgrAI enzyme that shed light on its catalytic function. First, we present the cryo-EM structure of filamentous SgrAI bound to intact primary site DNA and Ca2+ resolved to ∼2.5 Å within the catalytic center, which represents the trapped enzyme–DNA complex prior to the DNA cleavage reaction. This structure reveals important conformational changes that contribute to the catalytic mechanism and the binding of a second divalent cation in the enzyme active site, which is expected to contribute to increased DNA cleavage activity of SgrAI in the filamentous state. Second, we present an X-ray crystal structure of DNA-free (apo) SgrAI resolved to 2.0 Å resolution, which reveals a disordered loop involved in DNA recognition. Collectively, these multiple new observations clarify the mechanism of expansion of DNA sequence specificity of SgrAI, including the indirect readout of sequence-dependent DNA structure, changes in protein–DNA interactions, and the disorder-to-order transition of a crucial DNA recognition element.
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Affiliation(s)
- Zelin Shan
- Laboratory of Genetics, The Salk Institute of Biological Sciences, La Jolla, CA, USA 92037
| | - Niloofar Ghadirian
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, USA 85721
| | - Dmitry Lyumkis
- Laboratory of Genetics, The Salk Institute of Biological Sciences, La Jolla, CA, USA 92037; Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA 92037.
| | - N C Horton
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ, USA 85721.
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4
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Srivastava A, Tiwari SP, Miyashita O, Tama F. Integrative/Hybrid Modeling Approaches for Studying Biomolecules. J Mol Biol 2020; 432:2846-2860. [DOI: 10.1016/j.jmb.2020.01.039] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/20/2020] [Accepted: 01/24/2020] [Indexed: 12/12/2022]
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5
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Horton JR, Yang J, Zhang X, Petronzio T, Fomenkov A, Wilson GG, Roberts RJ, Cheng X. Structure of HhaI endonuclease with cognate DNA at an atomic resolution of 1.0 Å. Nucleic Acids Res 2020; 48:1466-1478. [PMID: 31879785 PMCID: PMC7026639 DOI: 10.1093/nar/gkz1195] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 12/08/2019] [Accepted: 12/11/2019] [Indexed: 11/19/2022] Open
Abstract
HhaI, a Type II restriction endonuclease, recognizes the symmetric sequence 5′-GCG↓C-3′ in duplex DNA and cleaves (‘↓’) to produce fragments with 2-base, 3′-overhangs. We determined the structure of HhaI in complex with cognate DNA at an ultra-high atomic resolution of 1.0 Å. Most restriction enzymes act as dimers with two catalytic sites, and cleave the two strands of duplex DNA simultaneously, in a single binding event. HhaI, in contrast, acts as a monomer with only one catalytic site, and cleaves the DNA strands sequentially, one after the other. HhaI comprises three domains, each consisting of a mixed five-stranded β sheet with a defined function. The first domain contains the catalytic-site; the second contains residues for sequence recognition; and the third contributes to non-specific DNA binding. The active-site belongs to the ‘PD-D/EXK’ superfamily of nucleases and contains the motif SD-X11-EAK. The first two domains are similar in structure to two other monomeric restriction enzymes, HinP1I (G↓CGC) and MspI (C↓CGG), which produce fragments with 5′-overhangs. The third domain, present only in HhaI, shifts the positions of the recognition residues relative to the catalytic site enabling this enzyme to cleave the recognition sequence at a different position. The structure of M.HhaI, the biological methyltransferase partner of HhaI, was determined earlier. Together, these two structures represent the first natural pair of restriction-modification enzymes to be characterized in atomic detail.
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Affiliation(s)
- John R Horton
- Department of Epigenetics & Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Jie Yang
- Department of Epigenetics & Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Xing Zhang
- Department of Epigenetics & Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | | | | | | | | | - Xiaodong Cheng
- Department of Epigenetics & Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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Park CK, Horton NC. Structures, functions, and mechanisms of filament forming enzymes: a renaissance of enzyme filamentation. Biophys Rev 2019; 11:927-994. [PMID: 31734826 PMCID: PMC6874960 DOI: 10.1007/s12551-019-00602-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 10/24/2019] [Indexed: 12/19/2022] Open
Abstract
Filament formation by non-cytoskeletal enzymes has been known for decades, yet only relatively recently has its wide-spread role in enzyme regulation and biology come to be appreciated. This comprehensive review summarizes what is known for each enzyme confirmed to form filamentous structures in vitro, and for the many that are known only to form large self-assemblies within cells. For some enzymes, studies describing both the in vitro filamentous structures and cellular self-assembly formation are also known and described. Special attention is paid to the detailed structures of each type of enzyme filament, as well as the roles the structures play in enzyme regulation and in biology. Where it is known or hypothesized, the advantages conferred by enzyme filamentation are reviewed. Finally, the similarities, differences, and comparison to the SgrAI endonuclease system are also highlighted.
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Affiliation(s)
- Chad K. Park
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721 USA
| | - Nancy C. Horton
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721 USA
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7
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Polley S, Lyumkis D, Horton NC. Mechanism of Filamentation-Induced Allosteric Activation of the SgrAI Endonuclease. Structure 2019; 27:1497-1507.e3. [PMID: 31447289 DOI: 10.1016/j.str.2019.08.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 07/10/2019] [Accepted: 08/02/2019] [Indexed: 02/07/2023]
Abstract
Filament formation by enzymes is increasingly recognized as an important phenomenon with potentially unique regulatory properties and biological roles. SgrAI is an allosterically regulated type II restriction endonuclease that forms filaments with enhanced DNA cleavage activity and altered sequence specificity. Here, we present the cryoelectron microscopy (cryo-EM) structure of the filament of SgrAI in its activated configuration. The structural data illuminate the mechanistic origin of hyperaccelerated DNA cleavage activity and suggests how indirect DNA sequence readout within filamentous SgrAI may enable recognition of substantially more nucleotide sequences than its low-activity form, thereby altering and partially relaxing its DNA sequence specificity. Together, substrate DNA binding, indirect readout, and filamentation simultaneously enhance SgrAI's catalytic activity and modulate substrate preference. This unusual enzyme mechanism may have evolved to perform the specialized functions of bacterial innate immunity in rapid defense against invading phage DNA without causing damage to the host DNA.
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Affiliation(s)
- Smarajit Polley
- Department of Biophysics, Bose Institute, Kolkata 700054, India
| | - Dmitry Lyumkis
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
| | - Nancy C Horton
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721, USA.
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8
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Horton NC, Park CK, Barahona C, Basantes LE, Ghadirian N. Kinetic Advantages of the Run‐On Oligomer or Filamentation Mechanism of a DNA Cleaving Enzyme. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.633.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- N C Horton
- Molecular and Cellular BiologyUniversity of ArizonaTucsonAZ
| | - Chad K Park
- Molecular and Cellular BiologyUniversity of ArizonaTucsonAZ
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9
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Barahona CJ, Basantes LE, Tompkins KJ, Heitman DM, Chukwu BI, Sanchez J, Sanchez JL, Ghadirian N, Park CK, Horton NC. The Need for Speed: Run-On Oligomer Filament Formation Provides Maximum Speed with Maximum Sequestration of Activity. J Virol 2019; 93:e01647-18. [PMID: 30518649 PMCID: PMC6384071 DOI: 10.1128/jvi.01647-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 11/26/2018] [Indexed: 01/29/2023] Open
Abstract
Here, we investigate an unusual antiviral mechanism developed in the bacterium Streptomyces griseus SgrAI is a type II restriction endonuclease that forms run-on oligomer filaments when activated and possesses both accelerated DNA cleavage activity and expanded DNA sequence specificity. Mutations disrupting the run-on oligomer filament eliminate the robust antiphage activity of wild-type SgrAI, and the observation that even relatively modest disruptions completely abolish this anti-viral activity shows that the greater speed imparted by the run-on oligomer filament mechanism is critical to its biological function. Simulations of DNA cleavage by SgrAI uncover the origins of the kinetic advantage of this newly described mechanism of enzyme regulation over more conventional mechanisms, as well as the origin of the sequestering effect responsible for the protection of the host genome against damaging DNA cleavage activity of activated SgrAI.IMPORTANCE This work is motivated by an interest in understanding the characteristics and advantages of a relatively newly discovered enzyme mechanism involving filament formation. SgrAI is an enzyme responsible for protecting against viral infections in its host bacterium and was one of the first such enzymes shown to utilize such a mechanism. In this work, filament formation by SgrAI is disrupted, and the effects on the speed of the purified enzyme as well as its function in cells are measured. It was found that even small disruptions, which weaken but do not destroy filament formation, eliminate the ability of SgrAI to protect cells from viral infection, its normal biological function. Simulations of enzyme activity were also performed and show how filament formation can greatly speed up an enzyme's activation compared to that of other known mechanisms, as well as to better localize its action to molecules of interest, such as invading phage DNA.
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Affiliation(s)
- Claudia J Barahona
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona, USA
| | - L Emilia Basantes
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona, USA
| | - Kassidy J Tompkins
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona, USA
| | - Desirae M Heitman
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona, USA
| | - Barbara I Chukwu
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona, USA
| | - Juan Sanchez
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona, USA
| | - Jonathan L Sanchez
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona, USA
| | - Niloofar Ghadirian
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona, USA
| | - Chad K Park
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona, USA
| | - N C Horton
- Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona, USA
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10
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Shen BW, Doyle L, Bradley P, Heiter DF, Lunnen KD, Wilson GG, Stoddard BL. Structure, subunit organization and behavior of the asymmetric Type IIT restriction endonuclease BbvCI. Nucleic Acids Res 2019; 47:450-467. [PMID: 30395313 PMCID: PMC6326814 DOI: 10.1093/nar/gky1059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 10/15/2018] [Accepted: 10/17/2018] [Indexed: 11/17/2022] Open
Abstract
BbvCI, a Type IIT restriction endonuclease, recognizes and cleaves the seven base pair sequence 5'-CCTCAGC-3', generating 3-base, 5'-overhangs. BbvCI is composed of two protein subunits, each containing one catalytic site. Either site can be inactivated by mutation resulting in enzyme variants that nick DNA in a strand-specific manner. Here we demonstrate that the holoenzyme is labile, with the R1 subunit dissociating at low pH. Crystallization of the R2 subunit under such conditions revealed an elongated dimer with the two catalytic sites located on opposite sides. Subsequent crystallization at physiological pH revealed a tetramer comprising two copies of each subunit, with a pair of deep clefts each containing two catalytic sites appropriately positioned and oriented for DNA cleavage. This domain organization was further validated with single-chain protein constructs in which the two enzyme subunits were tethered via peptide linkers of variable length. We were unable to crystallize a DNA-bound complex; however, structural similarity to previously crystallized restriction endonucleases facilitated creation of an energy-minimized model bound to DNA, and identification of candidate residues responsible for target recognition. Mutation of residues predicted to recognize the central C:G base pair resulted in an altered enzyme that recognizes and cleaves CCTNAGC (N = any base).
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Affiliation(s)
- Betty W Shen
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N., Seattle, WA 98109, USA
| | - Lindsey Doyle
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N., Seattle, WA 98109, USA
| | - Phil Bradley
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N., Seattle, WA 98109, USA
| | - Daniel F Heiter
- New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA
| | - Keith D Lunnen
- New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA
| | | | - Barry L Stoddard
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N., Seattle, WA 98109, USA
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11
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Park CK, Sanchez JL, Barahona C, Basantes LE, Sanchez J, Hernandez C, Horton NC. The run-on oligomer filament enzyme mechanism of SgrAI: Part 1. Assembly kinetics of the run-on oligomer filament. J Biol Chem 2018; 293:14585-14598. [PMID: 30068553 DOI: 10.1074/jbc.ra118.003680] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 07/30/2018] [Indexed: 01/06/2023] Open
Abstract
Filament or run-on oligomer formation by metabolic enzymes is now recognized as a widespread phenomenon having potentially unique enzyme regulatory properties and biological roles, and its dysfunction is implicated in human diseases such as cancer, diabetes, and developmental disorders. SgrAI is a bacterial allosteric type II restriction endonuclease that binds to invading phage DNA, may protect the host DNA from off-target cleavage activity, and forms run-on oligomeric filaments with enhanced DNA-cleavage activity and altered DNA sequence specificity. However, the mechanisms of SgrAI filament growth, cooperativity in filament formation, sequestration of enzyme activity, and advantages over other filament mechanisms remain unknown. In this first of a two-part series, we developed methods and models to derive association and dissociation rate constants of DNA-bound SgrAI in run-on oligomers and addressed the specific questions of cooperativity and filament growth mechanisms. We show that the derived rate constants are consistent with the run-on oligomer sizes determined by EM analysis and are most consistent with a noncooperative growth mode of the run-on oligomer. These models and methods are extended in the accompanying article to include the full DNA-cleavage pathway and address specific questions related to the run-on oligomer mechanism including the sequestration of DNA-cleavage activity and trapping of products.
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Affiliation(s)
- Chad K Park
- From the Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721
| | - Jonathan L Sanchez
- From the Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721
| | - Claudia Barahona
- From the Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721
| | - L Emilia Basantes
- From the Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721
| | - Juan Sanchez
- From the Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721
| | - Christian Hernandez
- From the Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721
| | - N C Horton
- From the Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721
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12
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Park CK, Sanchez JL, Barahona C, Basantes LE, Sanchez J, Hernandez C, Horton NC. The run-on oligomer filament enzyme mechanism of SgrAI: Part 2. Kinetic modeling of the full DNA cleavage pathway. J Biol Chem 2018; 293:14599-14615. [PMID: 30054273 DOI: 10.1074/jbc.ra118.003682] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 07/17/2018] [Indexed: 11/06/2022] Open
Abstract
Filament or run-on oligomer formation by enzymes is now recognized as a widespread phenomenon with potentially unique enzyme regulatory properties and biological roles. SgrAI is an allosteric type II restriction endonuclease that forms run-on oligomeric filaments with activated DNA cleavage activity and altered DNA sequence specificity. In this two-part work, we measure individual steps in the run-on oligomer filament mechanism to address specific questions of cooperativity, trapping, filament growth mechanisms, and sequestration of activity using fluorophore-labeled DNA, kinetic FRET measurements, and reaction modeling with global data fitting. The final models and rate constants show that the assembly step involving association of SgrAI-DNA complexes into the run-on oligomer filament is relatively slow (3-4 orders of magnitude slower than diffusion limited) and rate-limiting at low to moderate concentrations of SgrAI-DNA. The disassembly step involving dissociation of complexes of SgrAI-DNA from each other in the run-on oligomer filament is the next slowest step but is fast enough to limit the residence time of any one copy of SgrAI or DNA within the dynamic filament. Further, the rate constant for DNA cleavage is found to be 4 orders of magnitude faster in the run-on oligomer filament than in isolated SgrAI-DNA complexes and faster than dissociation of SgrAI-DNA complexes from the run-on oligomer filament, making the reaction efficient in that each association into the filament likely leads to DNA cleavage before filament dissociation.
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Affiliation(s)
- Chad K Park
- From the Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721
| | - Jonathan L Sanchez
- From the Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721
| | - Claudia Barahona
- From the Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721
| | - L Emilia Basantes
- From the Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721
| | - Juan Sanchez
- From the Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721
| | - Christian Hernandez
- From the Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721
| | - N C Horton
- From the Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721
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13
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Tamulaitiene G, Jovaisaite V, Tamulaitis G, Songailiene I, Manakova E, Zaremba M, Grazulis S, Xu SY, Siksnys V. Restriction endonuclease AgeI is a monomer which dimerizes to cleave DNA. Nucleic Acids Res 2017; 45:3547-3558. [PMID: 28039325 PMCID: PMC5389614 DOI: 10.1093/nar/gkw1310] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 12/13/2016] [Accepted: 12/19/2016] [Indexed: 01/19/2023] Open
Abstract
Although all Type II restriction endonucleases catalyze phosphodiester bond hydrolysis within or close to their DNA target sites, they form different oligomeric assemblies ranging from monomers, dimers, tetramers to higher order oligomers to generate a double strand break in DNA. Type IIP restriction endonuclease AgeI recognizes a palindromic sequence 5΄-A/CCGGT-3΄ and cuts it ('/' denotes the cleavage site) producing staggered DNA ends. Here, we present crystal structures of AgeI in apo and DNA-bound forms. The structure of AgeI is similar to the restriction enzymes that share in their target sites a conserved CCGG tetranucleotide and a cleavage pattern. Structure analysis and biochemical data indicate, that AgeI is a monomer in the apo-form both in the crystal and in solution, however, it binds and cleaves the palindromic target site as a dimer. DNA cleavage mechanism of AgeI is novel among Type IIP restriction endonucleases.
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Affiliation(s)
- Giedre Tamulaitiene
- Institute of Biotechnology, Vilnius University, Sauletekio al. 7, LT-10257 Vilnius, Lithuania
| | - Virginija Jovaisaite
- Institute of Biotechnology, Vilnius University, Sauletekio al. 7, LT-10257 Vilnius, Lithuania
| | - Gintautas Tamulaitis
- Institute of Biotechnology, Vilnius University, Sauletekio al. 7, LT-10257 Vilnius, Lithuania
| | - Inga Songailiene
- Institute of Biotechnology, Vilnius University, Sauletekio al. 7, LT-10257 Vilnius, Lithuania
| | - Elena Manakova
- Institute of Biotechnology, Vilnius University, Sauletekio al. 7, LT-10257 Vilnius, Lithuania
| | - Mindaugas Zaremba
- Institute of Biotechnology, Vilnius University, Sauletekio al. 7, LT-10257 Vilnius, Lithuania
| | - Saulius Grazulis
- Institute of Biotechnology, Vilnius University, Sauletekio al. 7, LT-10257 Vilnius, Lithuania
| | - Shuang-yong Xu
- New England Biolabs, Inc. 240 County Road, Ipswich, MA 01938, USA
| | - Virginijus Siksnys
- Institute of Biotechnology, Vilnius University, Sauletekio al. 7, LT-10257 Vilnius, Lithuania
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14
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Tamulaitis G, Rutkauskas M, Zaremba M, Grazulis S, Tamulaitiene G, Siksnys V. Functional significance of protein assemblies predicted by the crystal structure of the restriction endonuclease BsaWI. Nucleic Acids Res 2015; 43:8100-10. [PMID: 26240380 PMCID: PMC4652773 DOI: 10.1093/nar/gkv768] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 07/17/2015] [Indexed: 02/03/2023] Open
Abstract
Type II restriction endonuclease BsaWI recognizes a degenerated sequence 5′-W/CCGGW-3′ (W stands for A or T, ‘/’ denotes the cleavage site). It belongs to a large family of restriction enzymes that contain a conserved CCGG tetranucleotide in their target sites. These enzymes are arranged as dimers or tetramers, and require binding of one, two or three DNA targets for their optimal catalytic activity. Here, we present a crystal structure and biochemical characterization of the restriction endonuclease BsaWI. BsaWI is arranged as an ‘open’ configuration dimer and binds a single DNA copy through a minor groove contacts. In the crystal primary BsaWI dimers form an indefinite linear chain via the C-terminal domain contacts implying possible higher order aggregates. We show that in solution BsaWI protein exists in a dimer-tetramer-oligomer equilibrium, but in the presence of specific DNA forms a tetramer bound to two target sites. Site-directed mutagenesis and kinetic experiments show that BsaWI is active as a tetramer and requires two target sites for optimal activity. We propose BsaWI mechanism that shares common features both with dimeric Ecl18kI/SgrAI and bona fide tetrameric NgoMIV/SfiI enzymes.
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Affiliation(s)
- Gintautas Tamulaitis
- Department of Protein-DNA Interactions, Institute of Biotechnology, Vilnius University, Graiciuno 8, LT-02241 Vilnius, Lithuania
| | - Marius Rutkauskas
- Department of Protein-DNA Interactions, Institute of Biotechnology, Vilnius University, Graiciuno 8, LT-02241 Vilnius, Lithuania
| | - Mindaugas Zaremba
- Department of Protein-DNA Interactions, Institute of Biotechnology, Vilnius University, Graiciuno 8, LT-02241 Vilnius, Lithuania
| | - Saulius Grazulis
- Department of Protein-DNA Interactions, Institute of Biotechnology, Vilnius University, Graiciuno 8, LT-02241 Vilnius, Lithuania
| | - Giedre Tamulaitiene
- Department of Protein-DNA Interactions, Institute of Biotechnology, Vilnius University, Graiciuno 8, LT-02241 Vilnius, Lithuania
| | - Virginijus Siksnys
- Department of Protein-DNA Interactions, Institute of Biotechnology, Vilnius University, Graiciuno 8, LT-02241 Vilnius, Lithuania
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15
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Shah S, Sanchez J, Stewart A, Piperakis MM, Cosstick R, Nichols C, Park CK, Ma X, Wysocki V, Bitinaite J, Horton NC. Probing the run-on oligomer of activated SgrAI bound to DNA. PLoS One 2015; 10:e0124783. [PMID: 25880668 PMCID: PMC4399878 DOI: 10.1371/journal.pone.0124783] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2015] [Accepted: 03/05/2015] [Indexed: 02/04/2023] Open
Abstract
SgrAI is a type II restriction endonuclease with an unusual mechanism of activation involving run-on oligomerization. The run-on oligomer is formed from complexes of SgrAI bound to DNA containing its 8 bp primary recognition sequence (uncleaved or cleaved), and also binds (and thereby activates for DNA cleavage) complexes of SgrAI bound to secondary site DNA sequences which contain a single base substitution in either the 1st/8th or the 2nd/7th position of the primary recognition sequence. This modulation of enzyme activity via run-on oligomerization is a newly appreciated phenomenon that has been shown for a small but increasing number of enzymes. One outstanding question regarding the mechanistic model for SgrAI is whether or not the activating primary site DNA must be cleaved by SgrAI prior to inducing activation. Herein we show that an uncleavable primary site DNA containing a 3'-S-phosphorothiolate is in fact able to induce activation. In addition, we now show that cleavage of secondary site DNA can be activated to nearly the same degree as primary, provided a sufficient number of flanking base pairs are present. We also show differences in activation and cleavage of the two types of secondary site, and that effects of selected single site substitutions in SgrAI, as well as measured collisional cross-sections from previous work, are consistent with the cryo-electron microscopy model for the run-on activated oligomer of SgrAI bound to DNA.
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Affiliation(s)
- Santosh Shah
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, United States of America
| | - Jonathan Sanchez
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, United States of America
| | - Andrew Stewart
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, United States of America
- Genetics Graduate Program, University of Arizona, Tucson, AZ 85721, United States of America
| | - Michael M. Piperakis
- Department of Chemistry, University of Liverpool, Liverpool, United Kingdom, L69 7ZD, United States of America
| | - Richard Cosstick
- Department of Chemistry, University of Liverpool, Liverpool, United Kingdom, L69 7ZD, United States of America
| | - Claire Nichols
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, United States of America
| | - Chad K. Park
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, United States of America
| | - Xin Ma
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, United States of America
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, OH 43210, United States of America
| | - Vicki Wysocki
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, United States of America
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, OH 43210, United States of America
| | - Jurate Bitinaite
- New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, United States of America
| | - Nancy C. Horton
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, 85721, United States of America
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16
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Abstract
Members of the FET protein family, consisting of FUS, EWSR1, and TAF15, bind to RNA and contribute to the control of transcription, RNA processing, and the cytoplasmic fates of messenger RNAs in metazoa. FET proteins can also bind DNA, which may be important in transcription and DNA damage responses. FET proteins are of medical interest because chromosomal rearrangements of their genes promote various sarcomas and because point mutations in FUS or TAF15 can cause neurodegenerative diseases such as amyotrophic lateral sclerosis and frontotemporal lobar dementia. Recent results suggest that both the normal and pathological effects of FET proteins are modulated by low-complexity or prion-like domains, which can form higher-order assemblies with novel interaction properties. Herein, we review FET proteins with an emphasis on how the biochemical properties of FET proteins may relate to their biological functions and to pathogenesis.
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Affiliation(s)
- Jacob C Schwartz
- Howard Hughes Medical Institute, Department of Chemistry and Biochemistry, and BioFrontiers Institute, University of Colorado, Boulder, Colorado 80309; , ,
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17
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Pingoud A, Wilson GG, Wende W. Type II restriction endonucleases--a historical perspective and more. Nucleic Acids Res 2014; 42:7489-527. [PMID: 24878924 PMCID: PMC4081073 DOI: 10.1093/nar/gku447] [Citation(s) in RCA: 169] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 05/02/2014] [Accepted: 05/07/2014] [Indexed: 12/17/2022] Open
Abstract
This article continues the series of Surveys and Summaries on restriction endonucleases (REases) begun this year in Nucleic Acids Research. Here we discuss 'Type II' REases, the kind used for DNA analysis and cloning. We focus on their biochemistry: what they are, what they do, and how they do it. Type II REases are produced by prokaryotes to combat bacteriophages. With extreme accuracy, each recognizes a particular sequence in double-stranded DNA and cleaves at a fixed position within or nearby. The discoveries of these enzymes in the 1970s, and of the uses to which they could be put, have since impacted every corner of the life sciences. They became the enabling tools of molecular biology, genetics and biotechnology, and made analysis at the most fundamental levels routine. Hundreds of different REases have been discovered and are available commercially. Their genes have been cloned, sequenced and overexpressed. Most have been characterized to some extent, but few have been studied in depth. Here, we describe the original discoveries in this field, and the properties of the first Type II REases investigated. We discuss the mechanisms of sequence recognition and catalysis, and the varied oligomeric modes in which Type II REases act. We describe the surprising heterogeneity revealed by comparisons of their sequences and structures.
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Affiliation(s)
- Alfred Pingoud
- Institute of Biochemistry, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 58, D-35392 Giessen, Germany
| | - Geoffrey G Wilson
- New England Biolabs Inc., 240 County Road, Ipswich, MA 01938-2723, USA
| | - Wolfgang Wende
- Institute of Biochemistry, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 58, D-35392 Giessen, Germany
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18
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Horton JR, Borgaro JG, Griggs RM, Quimby A, Guan S, Zhang X, Wilson GG, Zheng Y, Zhu Z, Cheng X. Structure of 5-hydroxymethylcytosine-specific restriction enzyme, AbaSI, in complex with DNA. Nucleic Acids Res 2014; 42:7947-59. [PMID: 24895434 PMCID: PMC4081097 DOI: 10.1093/nar/gku497] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AbaSI, a member of the PvuRts1I-family of modification-dependent restriction endonucleases, cleaves deoxyribonucleic acid (DNA) containing 5-hydroxymethylctosine (5hmC) and glucosylated 5hmC (g5hmC), but not DNA containing unmodified cytosine. AbaSI has been used as a tool for mapping the genomic locations of 5hmC, an important epigenetic modification in the DNA of higher organisms. Here we report the crystal structures of AbaSI in the presence and absence of DNA. These structures provide considerable, although incomplete, insight into how this enzyme acts. AbaSI appears to be mainly a homodimer in solution, but interacts with DNA in our structures as a homotetramer. Each AbaSI subunit comprises an N-terminal, Vsr-like, cleavage domain containing a single catalytic site, and a C-terminal, SRA-like, 5hmC-binding domain. Two N-terminal helices mediate most of the homodimer interface. Dimerization brings together the two catalytic sites required for double-strand cleavage, and separates the 5hmC binding-domains by ∼70 Å, consistent with the known activity of AbaSI which cleaves DNA optimally between symmetrically modified cytosines ∼22 bp apart. The eukaryotic SET and RING-associated (SRA) domains bind to DNA containing 5-methylcytosine (5mC) in the hemi-methylated CpG sequence. They make contacts in both the major and minor DNA grooves, and flip the modified cytosine out of the helix into a conserved binding pocket. In contrast, the SRA-like domain of AbaSI, which has no sequence specificity, contacts only the minor DNA groove, and in our current structures the 5hmC remains intra-helical. A conserved, binding pocket is nevertheless present in this domain, suitable for accommodating 5hmC and g5hmC. We consider it likely, therefore, that base-flipping is part of the recognition and cleavage mechanism of AbaSI, but that our structures represent an earlier, pre-flipped stage, prior to actual recognition.
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Affiliation(s)
- John R Horton
- Department of Biochemistry, Emory University School of Medicine, 1510 Clifton Road, Atlanta, Georgia 30322, USA
| | - Janine G Borgaro
- New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA
| | - Rose M Griggs
- Department of Biochemistry, Emory University School of Medicine, 1510 Clifton Road, Atlanta, Georgia 30322, USA
| | - Aine Quimby
- New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA
| | - Shengxi Guan
- New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA
| | - Xing Zhang
- Department of Biochemistry, Emory University School of Medicine, 1510 Clifton Road, Atlanta, Georgia 30322, USA
| | | | - Yu Zheng
- New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA
| | - Zhenyu Zhu
- New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA
| | - Xiaodong Cheng
- Department of Biochemistry, Emory University School of Medicine, 1510 Clifton Road, Atlanta, Georgia 30322, USA
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19
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Horton JR, Nugent RL, Li A, Mabuchi MY, Fomenkov A, Cohen-Karni D, Griggs RM, Zhang X, Wilson GG, Zheng Y, Xu SY, Cheng X. Structure and mutagenesis of the DNA modification-dependent restriction endonuclease AspBHI. Sci Rep 2014; 4:4246. [PMID: 24604015 PMCID: PMC3946040 DOI: 10.1038/srep04246] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 02/13/2014] [Indexed: 12/13/2022] Open
Abstract
The modification-dependent restriction endonuclease AspBHI recognizes 5-methylcytosine (5mC) in the double-strand DNA sequence context of (C/T)(C/G)(5mC)N(C/G) (N = any nucleotide) and cleaves the two strands a fixed distance (N12/N16) 3′ to the modified cytosine. We determined the crystal structure of the homo-tetrameric AspBHI. Each subunit of the protein comprises two domains: an N-terminal DNA-recognition domain and a C-terminal DNA cleavage domain. The N-terminal domain is structurally similar to the eukaryotic SET and RING-associated (SRA) domain, which is known to bind to a hemi-methylated CpG dinucleotide. The C-terminal domain is structurally similar to classic Type II restriction enzymes and contains the endonuclease catalytic-site motif of DX20EAK. To understand how specific amino acids affect AspBHI recognition preference, we generated a homology model of the AspBHI-DNA complex, and probed the importance of individual amino acids by mutagenesis. Ser41 and Arg42 are predicted to be located in the DNA minor groove 5′ to the modified cytosine. Substitution of Ser41 with alanine (S41A) and cysteine (S41C) resulted in mutants with altered cleavage activity. All 19 Arg42 variants resulted in loss of endonuclease activity.
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Affiliation(s)
- John R Horton
- Department of Biochemistry, Emory University School of Medicine, 1510 Clifton Road, Atlanta, Georgia 30322, USA
| | - Rebecca L Nugent
- 1] New England Biolabs, 240 County Road, Ipswich, MA 01938, USA [2]
| | - Andrew Li
- New England Biolabs, 240 County Road, Ipswich, MA 01938, USA
| | | | - Alexey Fomenkov
- New England Biolabs, 240 County Road, Ipswich, MA 01938, USA
| | | | - Rose M Griggs
- Department of Biochemistry, Emory University School of Medicine, 1510 Clifton Road, Atlanta, Georgia 30322, USA
| | - Xing Zhang
- Department of Biochemistry, Emory University School of Medicine, 1510 Clifton Road, Atlanta, Georgia 30322, USA
| | | | - Yu Zheng
- New England Biolabs, 240 County Road, Ipswich, MA 01938, USA
| | - Shuang-yong Xu
- New England Biolabs, 240 County Road, Ipswich, MA 01938, USA
| | - Xiaodong Cheng
- Department of Biochemistry, Emory University School of Medicine, 1510 Clifton Road, Atlanta, Georgia 30322, USA
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20
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Affiliation(s)
- David T F Dryden
- School of Chemistry, University of Edinburgh, The King's Buildings, Edinburgh EH9 3JJ, UK.
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