1
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Ruan Q, Schaub JM, Macdonald PJ, Tetin SY. Method for direct measuring antibody affinity in biological sample. Biophys J 2023; 122:275a. [PMID: 36783358 DOI: 10.1016/j.bpj.2022.11.1569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
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2
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Schaub JM, Ruan Q, Tetin SY. Epifluorescent single-molecule counting with Streptavidin-Phycoerythrin conjugates. Biophys J 2023; 122:276a. [PMID: 36783366 DOI: 10.1016/j.bpj.2022.11.1572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
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3
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Schaub JM, Ruan Q, Tetin SY. Epifluorescent single-molecule counting with Streptavidin-Phycoerythrin conjugates. Anal Biochem 2022; 659:114955. [PMID: 36265689 DOI: 10.1016/j.ab.2022.114955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 10/10/2022] [Indexed: 12/14/2022]
Abstract
Single-molecule methods, specifically single-molecule counting, convey high sensitivity in research applications. However, single-molecule counting experiments require specialized equipment or consumables to perform. We demonstrate the utility of using bright Streptavidin-Phycoerythrin (SA-PE) conjugates and an epifluorescence microscope, for single-molecule counting applications. In this work, we show that we can visualize single-molecules on glass surfaces, perform single-molecule diagnostic assays on magnetic microparticles, and image individual foci on cell surfaces. This approach is simple and effective for researchers interested in single-molecule counting.
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Affiliation(s)
- Jeffrey M Schaub
- Applied Research and Technology, Abbott Diagnostics Division, Abbott Laboratories, Abbott Park, IL, 60064, USA
| | - Qiaoqiao Ruan
- Applied Research and Technology, Abbott Diagnostics Division, Abbott Laboratories, Abbott Park, IL, 60064, USA
| | - Sergey Y Tetin
- Applied Research and Technology, Abbott Diagnostics Division, Abbott Laboratories, Abbott Park, IL, 60064, USA.
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4
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Schaub JM, Soniat MM, Finkelstein IJ. Polymerase theta-helicase promotes end joining by stripping single-stranded DNA-binding proteins and bridging DNA ends. Nucleic Acids Res 2022; 50:3911-3921. [PMID: 35357490 PMCID: PMC9023281 DOI: 10.1093/nar/gkac119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 01/20/2022] [Accepted: 03/29/2022] [Indexed: 01/20/2023] Open
Abstract
Homologous recombination-deficient cancers rely on DNA polymerase Theta (Polθ)-Mediated End Joining (TMEJ), an alternative double-strand break repair pathway. Polθ is the only vertebrate polymerase that encodes an N-terminal superfamily 2 (SF2) helicase domain, but the role of this helicase domain in TMEJ remains unclear. Using single-molecule imaging, we demonstrate that Polθ-helicase (Polθ-h) is a highly processive single-stranded DNA (ssDNA) motor protein that can efficiently strip Replication Protein A (RPA) from ssDNA. Polθ-h also has a limited capacity for disassembling RAD51 filaments but is not processive on double-stranded DNA. Polθ-h can bridge two non-complementary DNA strands in trans. PARylation of Polθ-h by PARP-1 resolves these DNA bridges. We conclude that Polθ-h removes RPA and RAD51 filaments and mediates bridging of DNA overhangs to aid in polymerization by the Polθ polymerase domain.
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Affiliation(s)
- Jeffrey M Schaub
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Michael M Soniat
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Ilya J Finkelstein
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA.,Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX 78712, USA
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5
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Jack A, Kim Y, Strom AR, Lee DS, Williams B, Schaub JM, Kellogg EH, Finkelstein IJ, Ferro L, Yildiz A, Brangwynne CP. Compartmentalization of telomeres through DNA-scaffolded phase separation. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.1219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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6
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Jack A, Kim Y, Strom AR, Lee DSW, Williams B, Schaub JM, Kellogg EH, Finkelstein IJ, Ferro LS, Yildiz A, Brangwynne CP. Compartmentalization of telomeres through DNA-scaffolded phase separation. Dev Cell 2022; 57:277-290.e9. [PMID: 35077681 PMCID: PMC8988007 DOI: 10.1016/j.devcel.2021.12.017] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 08/25/2021] [Accepted: 12/15/2021] [Indexed: 12/20/2022]
Abstract
Telomeres form unique nuclear compartments that prevent degradation and fusion of chromosome ends by recruiting shelterin proteins and regulating access of DNA damage repair factors. To understand how these dynamic components protect chromosome ends, we combine in vivo biophysical interrogation and in vitro reconstitution of human shelterin. We show that shelterin components form multicomponent liquid condensates with selective biomolecular partitioning on telomeric DNA. Tethering and anomalous diffusion prevent multiple telomeres from coalescing into a single condensate in mammalian cells. However, telomeres coalesce when brought into contact via an optogenetic approach. TRF1 and TRF2 subunits of shelterin drive phase separation, and their N-terminal domains specify interactions with telomeric DNA in vitro. Telomeric condensates selectively recruit telomere-associated factors and regulate access of DNA damage repair factors. We propose that shelterin mediates phase separation of telomeric chromatin, which underlies the dynamic yet persistent nature of the end-protection mechanism.
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Affiliation(s)
- Amanda Jack
- Biophysics Graduate Group, University of California, Berkeley, CA 94720, USA
| | - Yoonji Kim
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Amy R Strom
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Daniel S W Lee
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Byron Williams
- Molecular Biology and Genetics, Cornell University, Ithaca, NY 14850, USA
| | - Jeffrey M Schaub
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | | | - Ilya J Finkelstein
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Luke S Ferro
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
| | - Ahmet Yildiz
- Biophysics Graduate Group, University of California, Berkeley, CA 94720, USA; Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA; Physics Department, University of California, Berkeley, CA 94720, USA.
| | - Clifford P Brangwynne
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA; Howard Hughes Medical Institute, Princeton University, Princeton NJ 08544, USA.
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7
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Schaub JM, Chou CW, Kuo HC, Javanmardi K, Hsieh CL, Goldsmith J, DiVenere AM, Le KC, Wrapp D, Byrne PO, Hjorth CK, Johnson NV, Ludes-Meyers J, Nguyen AW, Wang N, Lavinder JJ, Ippolito GC, Maynard JA, McLellan JS, Finkelstein IJ. Expression and characterization of SARS-CoV-2 spike proteins. Nat Protoc 2021; 16:5339-5356. [PMID: 34611365 PMCID: PMC9665560 DOI: 10.1038/s41596-021-00623-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 09/06/2021] [Indexed: 02/08/2023]
Abstract
The severe acute respiratory syndrome coronavirus 2 spike protein is a critical component of coronavirus disease 2019 vaccines and diagnostics and is also a therapeutic target. However, the spike protein is difficult to produce recombinantly because it is a large trimeric class I fusion membrane protein that is metastable and heavily glycosylated. We recently developed a prefusion-stabilized spike variant, termed HexaPro for six stabilizing proline substitutions, that can be expressed with a yield of >30 mg/L in ExpiCHO cells. This protocol describes an optimized workflow for expressing and biophysically characterizing rationally engineered spike proteins in Freestyle 293 and ExpiCHO cell lines. Although we focus on HexaPro, this protocol has been used to purify over a hundred different spike variants in our laboratories. We also provide guidance on expression quality control, long-term storage, and uses in enzyme-linked immunosorbent assays. The entire protocol, from transfection to biophysical characterization, can be completed in 7 d by researchers with basic tissue cell culture and protein purification expertise.
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Affiliation(s)
- Jeffrey M Schaub
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Chia-Wei Chou
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Hung-Che Kuo
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Kamyab Javanmardi
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Ching-Lin Hsieh
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Jory Goldsmith
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Andrea M DiVenere
- Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Kevin C Le
- Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Daniel Wrapp
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Patrick O Byrne
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Christy K Hjorth
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Nicole V Johnson
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - John Ludes-Meyers
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Annalee W Nguyen
- Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Nianshuang Wang
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Jason J Lavinder
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
- Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Gregory C Ippolito
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
- Department of Oncology, Dell Medical School, The University of Texas at Austin, Austin, TX, USA
| | - Jennifer A Maynard
- Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Jason S McLellan
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA
| | - Ilya J Finkelstein
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA.
- Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX, USA.
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8
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Blevins MS, Walker JN, Schaub JM, Finkelstein IJ, Brodbelt JS. Characterization of the T4 gp32-ssDNA complex by native, cross-linking, and ultraviolet photodissociation mass spectrometry. Chem Sci 2021; 12:13764-13776. [PMID: 34760161 PMCID: PMC8549804 DOI: 10.1039/d1sc02861h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 09/23/2021] [Indexed: 12/28/2022] Open
Abstract
Protein-DNA interactions play crucial roles in DNA replication across all living organisms. Here, we apply a suite of mass spectrometry (MS) tools to characterize a protein-ssDNA complex, T4 gp32·ssDNA, with results that both support previous studies and simultaneously uncover novel insight into this non-covalent biological complex. Native mass spectrometry of the protein reveals the co-occurrence of Zn-bound monomers and homodimers, while addition of differing lengths of ssDNA generates a variety of protein:ssDNA complex stoichiometries (1 : 1, 2 : 1, 3 : 1), indicating sequential association of gp32 monomers with ssDNA. Ultraviolet photodissociation (UVPD) mass spectrometry allows characterization of the binding site of the ssDNA within the protein monomer via analysis of holo ions, i.e. ssDNA-containing protein fragments, enabling interrogation of disordered regions of the protein which are inaccessible via traditional crystallographic techniques. Finally, two complementary cross-linking (XL) approaches, bottom-up analysis of the crosslinked complexes as well as MS1 analysis of the intact complexes, are used to showcase the absence of ssDNA binding with the intact cross-linked homodimer and to generate two homodimer gp32 model structures which highlight that the homodimer interface overlaps with the monomer ssDNA-binding site. These models suggest that the homodimer may function in a regulatory capacity by controlling the extent of ssDNA binding of the protein monomer. In sum, this work underscores the utility of a multi-faceted mass spectrometry approach for detailed investigation of non-covalent protein-DNA complexes.
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Affiliation(s)
- Molly S Blevins
- Department of Chemistry, University of Texas at Austin Austin TX 78712 USA
| | - Jada N Walker
- Department of Chemistry, University of Texas at Austin Austin TX 78712 USA
| | - Jeffrey M Schaub
- Department of Molecular Biosciences, University of Texas at Austin Austin TX 78712 USA
| | - Ilya J Finkelstein
- Department of Molecular Biosciences, University of Texas at Austin Austin TX 78712 USA
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9
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Zhang H, Schaub JM, Finkelstein IJ. RADX condenses single-stranded DNA to antagonize RAD51 loading. Nucleic Acids Res 2020; 48:7834-7843. [PMID: 32621611 PMCID: PMC7430644 DOI: 10.1093/nar/gkaa559] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 06/15/2020] [Accepted: 06/18/2020] [Indexed: 12/31/2022] Open
Abstract
RADX is a mammalian single-stranded DNA-binding protein that stabilizes telomeres and stalled replication forks. Cellular biology studies have shown that the balance between RADX and Replication Protein A (RPA) is critical for DNA replication integrity. RADX is also a negative regulator of RAD51-mediated homologous recombination at stalled forks. However, the mechanism of RADX acting on DNA and its interactions with RPA and RAD51 are enigmatic. Using single-molecule imaging of the key proteins in vitro, we reveal that RADX condenses ssDNA filaments, even when the ssDNA is coated with RPA at physiological protein ratios. RADX compacts RPA-coated ssDNA filaments via higher-order assemblies that can capture ssDNA in trans. Furthermore, RADX blocks RPA displacement by RAD51 and prevents RAD51 loading on ssDNA. Our results indicate that RADX is an ssDNA condensation protein that inhibits RAD51 filament formation and may antagonize other ssDNA-binding proteins on RPA-coated ssDNA.
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Affiliation(s)
- Hongshan Zhang
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Jeffrey M Schaub
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Ilya J Finkelstein
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA.,Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA
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10
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Hsieh CL, Goldsmith JA, Schaub JM, DiVenere AM, Kuo HC, Javanmardi K, Le KC, Wrapp D, Lee AG, Liu Y, Chou CW, Byrne PO, Hjorth CK, Johnson NV, Ludes-Meyers J, Nguyen AW, Park J, Wang N, Amengor D, Lavinder JJ, Ippolito GC, Maynard JA, Finkelstein IJ, McLellan JS. Structure-based design of prefusion-stabilized SARS-CoV-2 spikes. Science 2020. [PMID: 32703906 DOI: 10.1126/science:abd0826] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The coronavirus disease 2019 (COVID-19) pandemic has led to accelerated efforts to develop therapeutics and vaccines. A key target of these efforts is the spike (S) protein, which is metastable and difficult to produce recombinantly. We characterized 100 structure-guided spike designs and identified 26 individual substitutions that increased protein yields and stability. Testing combinations of beneficial substitutions resulted in the identification of HexaPro, a variant with six beneficial proline substitutions exhibiting higher expression than its parental construct (by a factor of 10) as well as the ability to withstand heat stress, storage at room temperature, and three freeze-thaw cycles. A cryo-electron microscopy structure of HexaPro at a resolution of 3.2 angstroms confirmed that it retains the prefusion spike conformation. High-yield production of a stabilized prefusion spike protein will accelerate the development of vaccines and serological diagnostics for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
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Affiliation(s)
- Ching-Lin Hsieh
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Jory A Goldsmith
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Jeffrey M Schaub
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Andrea M DiVenere
- Department of Chemical Engineering, University of Texas, Austin, TX 78712, USA
| | - Hung-Che Kuo
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Kamyab Javanmardi
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Kevin C Le
- Department of Chemical Engineering, University of Texas, Austin, TX 78712, USA
| | - Daniel Wrapp
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Alison G Lee
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Yutong Liu
- Department of Chemical Engineering, University of Texas, Austin, TX 78712, USA
| | - Chia-Wei Chou
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Patrick O Byrne
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Christy K Hjorth
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Nicole V Johnson
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - John Ludes-Meyers
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Annalee W Nguyen
- Department of Chemical Engineering, University of Texas, Austin, TX 78712, USA
| | - Juyeon Park
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Nianshuang Wang
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Dzifa Amengor
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Jason J Lavinder
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
- Department of Chemical Engineering, University of Texas, Austin, TX 78712, USA
| | - Gregory C Ippolito
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
- Department of Oncology, Dell Medical School, University of Texas, Austin, TX 78712, USA
| | - Jennifer A Maynard
- Department of Chemical Engineering, University of Texas, Austin, TX 78712, USA.
| | - Ilya J Finkelstein
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA.
- Center for Systems and Synthetic Biology, University of Texas, Austin, TX 78712, USA
| | - Jason S McLellan
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA.
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11
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Hsieh CL, Goldsmith JA, Schaub JM, DiVenere AM, Kuo HC, Javanmardi K, Le KC, Wrapp D, Lee AG, Liu Y, Chou CW, Byrne PO, Hjorth CK, Johnson NV, Ludes-Meyers J, Nguyen AW, Park J, Wang N, Amengor D, Lavinder JJ, Ippolito GC, Maynard JA, Finkelstein IJ, McLellan JS. Structure-based design of prefusion-stabilized SARS-CoV-2 spikes. Science 2020; 369:1501-1505. [PMID: 32703906 PMCID: PMC7402631 DOI: 10.1126/science.abd0826] [Citation(s) in RCA: 792] [Impact Index Per Article: 198.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 07/13/2020] [Indexed: 12/16/2022]
Abstract
The coronavirus disease 2019 (COVID-19) pandemic has led to accelerated efforts to develop therapeutics and vaccines. A key target of these efforts is the spike (S) protein, which is metastable and difficult to produce recombinantly. We characterized 100 structure-guided spike designs and identified 26 individual substitutions that increased protein yields and stability. Testing combinations of beneficial substitutions resulted in the identification of HexaPro, a variant with six beneficial proline substitutions exhibiting higher expression than its parental construct (by a factor of 10) as well as the ability to withstand heat stress, storage at room temperature, and three freeze-thaw cycles. A cryo-electron microscopy structure of HexaPro at a resolution of 3.2 angstroms confirmed that it retains the prefusion spike conformation. High-yield production of a stabilized prefusion spike protein will accelerate the development of vaccines and serological diagnostics for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
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Affiliation(s)
- Ching-Lin Hsieh
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Jory A Goldsmith
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Jeffrey M Schaub
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Andrea M DiVenere
- Department of Chemical Engineering, University of Texas, Austin, TX 78712, USA
| | - Hung-Che Kuo
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Kamyab Javanmardi
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Kevin C Le
- Department of Chemical Engineering, University of Texas, Austin, TX 78712, USA
| | - Daniel Wrapp
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Alison G Lee
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Yutong Liu
- Department of Chemical Engineering, University of Texas, Austin, TX 78712, USA
| | - Chia-Wei Chou
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Patrick O Byrne
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Christy K Hjorth
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Nicole V Johnson
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - John Ludes-Meyers
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Annalee W Nguyen
- Department of Chemical Engineering, University of Texas, Austin, TX 78712, USA
| | - Juyeon Park
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Nianshuang Wang
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Dzifa Amengor
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
| | - Jason J Lavinder
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
- Department of Chemical Engineering, University of Texas, Austin, TX 78712, USA
| | - Gregory C Ippolito
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA
- Department of Oncology, Dell Medical School, University of Texas, Austin, TX 78712, USA
| | - Jennifer A Maynard
- Department of Chemical Engineering, University of Texas, Austin, TX 78712, USA.
| | - Ilya J Finkelstein
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA.
- Center for Systems and Synthetic Biology, University of Texas, Austin, TX 78712, USA
| | - Jason S McLellan
- Department of Molecular Biosciences, University of Texas, Austin, TX 78712, USA.
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12
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Hsieh CL, Goldsmith JA, Schaub JM, DiVenere AM, Kuo HC, Javanmardi K, Le KC, Wrapp D, Lee AGW, Liu Y, Chou CW, Byrne PO, Hjorth CK, Johnson NV, Ludes-Meyers J, Nguyen AW, Park J, Wang N, Amengor D, Maynard JA, Finkelstein IJ, McLellan JS. Structure-based Design of Prefusion-stabilized SARS-CoV-2 Spikes. bioRxiv 2020:2020.05.30.125484. [PMID: 32577660 PMCID: PMC7302215 DOI: 10.1101/2020.05.30.125484] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
The COVID-19 pandemic caused by the novel coronavirus SARS-CoV-2 has led to accelerated efforts to develop therapeutics, diagnostics, and vaccines to mitigate this public health emergency. A key target of these efforts is the spike (S) protein, a large trimeric class I fusion protein that is metastable and difficult to produce recombinantly in large quantities. Here, we designed and expressed over 100 structure-guided spike variants based upon a previously determined cryo-EM structure of the prefusion SARS-CoV-2 spike. Biochemical, biophysical and structural characterization of these variants identified numerous individual substitutions that increased protein yields and stability. The best variant, HexaPro, has six beneficial proline substitutions leading to ~10-fold higher expression than its parental construct and is able to withstand heat stress, storage at room temperature, and multiple freeze-thaws. A 3.2 Å-resolution cryo-EM structure of HexaPro confirmed that it retains the prefusion spike conformation. High-yield production of a stabilized prefusion spike protein will accelerate the development of vaccines and serological diagnostics for SARS-CoV-2.
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Affiliation(s)
- Ching-Lin Hsieh
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
| | - Jory A. Goldsmith
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
| | - Jeffrey M. Schaub
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
| | - Andrea M. DiVenere
- Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712
| | - Hung-Che Kuo
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
| | - Kamyab Javanmardi
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
| | - Kevin C. Le
- Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712
| | - Daniel Wrapp
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
| | - Alison Gene-Wei Lee
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
| | - Yutong Liu
- Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712
| | - Chia-Wei Chou
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
| | - Patrick O. Byrne
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
| | - Christy K. Hjorth
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
| | - Nicole V. Johnson
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
| | - John Ludes-Meyers
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
| | - Annalee W. Nguyen
- Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712
| | - Juyeon Park
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
| | - Nianshuang Wang
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
| | - Dzifa Amengor
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
| | - Jennifer A. Maynard
- Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712
| | - Ilya J. Finkelstein
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, Texas 78712
| | - Jason S. McLellan
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712
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13
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Mallam AL, Sae-Lee W, Schaub JM, Tu F, Battenhouse A, Jang YJ, Kim J, Wallingford JB, Finkelstein IJ, Marcotte EM, Drew K. Systematic Discovery of Endogenous Human Ribonucleoprotein Complexes. Cell Rep 2019; 29:1351-1368.e5. [PMID: 31665645 PMCID: PMC6873818 DOI: 10.1016/j.celrep.2019.09.060] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 08/30/2019] [Accepted: 09/18/2019] [Indexed: 12/16/2022] Open
Abstract
RNA-binding proteins (RBPs) play essential roles in biology and are frequently associated with human disease. Although recent studies have systematically identified individual RNA-binding proteins, their higher-order assembly into ribonucleoprotein (RNP) complexes has not been systematically investigated. Here, we describe a proteomics method for systematic identification of RNP complexes in human cells. We identify 1,428 protein complexes that associate with RNA, indicating that more than 20% of known human protein complexes contain RNA. To explore the role of RNA in the assembly of each complex, we identify complexes that dissociate, change composition, or form stable protein-only complexes in the absence of RNA. We use our method to systematically identify cell-type-specific RNA-associated proteins in mouse embryonic stem cells and finally, distribute our resource, rna.MAP, in an easy-to-use online interface (rna.proteincomplexes.org). Our system thus provides a methodology for explorations across human tissues, disease states, and throughout all domains of life.
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Affiliation(s)
- Anna L Mallam
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA.
| | - Wisath Sae-Lee
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Jeffrey M Schaub
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Fan Tu
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Anna Battenhouse
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Yu Jin Jang
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Jonghwan Kim
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - John B Wallingford
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Ilya J Finkelstein
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Edward M Marcotte
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA.
| | - Kevin Drew
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA.
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14
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Abstract
Single-stranded DNA (ssDNA) is a critical intermediate in all DNA transactions. Because ssDNA is more flexible than double-stranded (ds) DNA, interactions with ssDNA-binding proteins (SSBs) may significantly compact or elongate the ssDNA molecule. Here, we develop and characterize low-complexity ssDNA curtains, a high-throughput single-molecule assay to simultaneously monitor protein binding and correlated ssDNA length changes on supported lipid bilayers. Low-complexity ssDNA is generated via rolling circle replication of short synthetic oligonucleotides, permitting control over the sequence composition and secondary structure-forming propensity. One end of the ssDNA is functionalized with a biotin, while the second is fluorescently labeled to track the overall DNA length. Arrays of ssDNA molecules are organized at microfabricated barriers for high-throughput single-molecule imaging. Using this assay, we demonstrate that E. coli SSB drastically and reversibly compacts ssDNA templates upon changes in NaCl concentration. We also examine the interactions between a phosphomimetic RPA and ssDNA. Our results indicate that RPA-ssDNA interactions are not significantly altered by these modifications. We anticipate that low-complexity ssDNA curtains will be broadly useful for single-molecule studies of ssDNA-binding proteins involved in DNA replication, transcription, and repair.
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Affiliation(s)
- Jeffrey M. Schaub
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology
| | - Hongshan Zhang
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology
| | - Michael M. Soniat
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology
| | - Ilya J. Finkelstein
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology
- Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas 78712, United States
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15
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Li S, Lowell AN, Yu F, Raveh A, Newmister SA, Bair N, Schaub JM, Williams RM, Sherman DH. Hapalindole/Ambiguine Biogenesis Is Mediated by a Cope Rearrangement, C-C Bond-Forming Cascade. J Am Chem Soc 2015; 137:15366-9. [PMID: 26629885 DOI: 10.1021/jacs.5b10136] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hapalindoles are bioactive indole alkaloids with fascinating polycyclic ring systems whose biosynthetic assembly mechanism has remained unknown since their initial discovery in the 1980s. In this study, we describe the fam gene cluster from the cyanobacterium Fischerella ambigua UTEX 1903 encoding hapalindole and ambiguine biosynthesis along with the characterization of two aromatic prenyltransferases, FamD1 and FamD2, and a previously undescribed cyclase, FamC1. These studies demonstrate that FamD2 and FamC1 act in concert to form the tetracyclic core ring system of the hapalindoles from cis-indole isonitrile and geranyl pyrophosphate through a presumed biosynthetic Cope rearrangement and subsequent 6-exo-trig cyclization/electrophilic aromatic substitution reaction.
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Affiliation(s)
| | | | | | | | | | - Nathan Bair
- Department of Chemistry, Colorado State University , Fort Collins, Colorado 80523, United States
| | | | - Robert M Williams
- Department of Chemistry, Colorado State University , Fort Collins, Colorado 80523, United States.,University of Colorado Cancer Center , Aurora, Colorado 80045, United States
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16
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Abstract
D-Arabinose 5-phosphate isomerases (APIs) catalyze the interconversion of D-ribulose 5-phosphate and D-arabinose 5-phosphate (A5P). A5P is an intermediate in the biosynthesis of 3-deoxy-D-manno-octulosonate (Kdo), an essential component of lipopolysaccharide, the lipopolysaccharide found in the outer membrane of Gram-negative bacteria. The genome of the Gram-positive pathogen Listeria monocytogenes contains a gene encoding a putative sugar isomerase domain API, Q723E8, with significant similarity to c3406, the only one of four APIs from Escherichia coli CFT073 that lacks a cystathionine-β-synthase domain. However, L. monocytogenes lacks genes encoding any of the other enzymes of the Kdo biosynthesis pathway. Realizing that the discovery of an API in a Gram-positive bacterium could provide insight into an alternate physiological role of A5P in the cell, we prepared and purified recombinant Q723E8. We found that Q723E8 does not possess API activity, but instead is a novel GPI (D-glucose 6-phosphate isomerase). However, the GPI activity of Q723E8 is weak compared with previously described GPIS. L. monocytogenes contains an ortholog of the well-studied two-domain bacterial GPI, so this maybe redundant. Based on this evidence glucose utilization is likely not the primary physiological role of Q723E8.
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Affiliation(s)
- David L Cech
- Department of Medicinal Chemistry, University of Michigan, 428 Church Street, Ann Arbor, MI, 48109-1065, USA,
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