1
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Miller LM, Draper BE, Wang JCY, Jarrold MF. Charge Detection Mass Spectrometry Reveals Favored Structures in the Assembly of Virus-Like Particles: Polymorphism in Norovirus GI.1. Anal Chem 2024. [PMID: 39074122 DOI: 10.1021/acs.analchem.4c01913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/31/2024]
Abstract
The main capsid protein (CP) of norovirus, the leading cause of gastroenteritis, is expected to self-assemble into virus-like particles with the same structure as the wild-type virus, a capsid with 180 CPs in a T = 3 icosahedron. Using charge detection mass spectrometry (CD-MS), we find that the norovirus GI.1 variant is structurally promiscuous, forming a wide variety of well-defined structures, some that are icosahedral capsids and others that are not. The structures that are present evolve with time and vary with solution conditions. The presence of icosahedral T = 3 and T = 4 capsids (240 CPs) under some conditions was confirmed by cryo-electron microscopy (cryo-EM). The cryo-EM studies also confirmed the presence of an unexpected prolate geometry based on an elongated T = 4 capsid with 300 CPs. In addition, CD-MS measurements indicate the presence of well-defined peaks with masses corresponding to 420, 480, 600, and 700 CPs. The peak corresponding to 420 CPs is probably due to an icosahedral T = 7 capsid, but this could not be confirmed by cryo-EM. It is possible that the T = 7 particles are too fragile to survive vitrification. There are no mass peaks associated with the T = 9 and T = 12 icosahedra with 540 and 720 CPs. The larger structures with 480, 600, and 700 CPs are not icosahedral; however, their measured charges suggest that they are hollow shells. The use of CD-MS to monitor virus-like particles assembly may have important applications in vaccine development and quality control.
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Affiliation(s)
- Lohra M Miller
- Chemistry Department, Indiana University, 800 E Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Benjamin E Draper
- Megadalton Solutions Inc, 3750 E Bluebird Ln, Bloomington, Indiana 47401, United States
| | - Joseph C-Y Wang
- Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania 17033, United States
| | - Martin F Jarrold
- Chemistry Department, Indiana University, 800 E Kirkwood Avenue, Bloomington, Indiana 47405, United States
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2
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Panicker LR, Kummari S, Keerthanaa MR, Rao Bommi J, Koteshwara Reddy K, Yugender Goud K. Trends and challenges in electroanalytical biosensing methodologies for infectious viral diseases. Bioelectrochemistry 2024; 156:108594. [PMID: 37984310 DOI: 10.1016/j.bioelechem.2023.108594] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 10/26/2023] [Accepted: 10/30/2023] [Indexed: 11/22/2023]
Abstract
Viral pandemic diseases have disruptive global consequences leading to millions of deaths and a severe impact on the global economy. Inadequate preventative protocols have led to an overwhelming demand for intensive care leading to uncontrollable burdens and even breakdown of healthcare sectors across many countries. The rapid detection of viral disease helps in the understanding of the relevant intricacies, helping to tackle infection with improved guidelines. Portable biosensor devices offer promising solutions by facilitating on-site detection of viral pathogens. This review summarizes the latest innovative strategies reported using electroanalytical methods for the screening of viral antigens. The structural components of viruses and their categories are presented followed by the various recognition elements and transduction techniques involved in biosensors. Core sections focus on biosensors reported for viral genomic detection(DNA and RNA) and antigenic capsid protein. Strategies for addressing the challenges of electroanalytical biosensing of viral components are also presented. The advantages, and disadvantages of biorecognition elements and nanozymes for the detection of viral disease are highlighted. Such technical insights will help researchers working in chemistry, and biochemistry as well as clinicians working in medical diagnostics.
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Affiliation(s)
- Lakshmi R Panicker
- Department of Chemistry, Indian Institute of Technology Palakkad, Palakkad, Kerala 678 557, India
| | - Shekher Kummari
- Department of Chemistry, Indian Institute of Technology Palakkad, Palakkad, Kerala 678 557, India
| | - M R Keerthanaa
- Department of Chemistry, Indian Institute of Technology Palakkad, Palakkad, Kerala 678 557, India
| | | | - K Koteshwara Reddy
- School of Material Science and Engineering, Purdue University, West Lafayette, IN, 47907, USA.
| | - K Yugender Goud
- Department of Chemistry, Indian Institute of Technology Palakkad, Palakkad, Kerala 678 557, India.
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3
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Zhang Y, Anbir S, McTiernan J, Li S, Worcester M, Mishra P, Colvin ME, Gopinathan A, Mohideen U, Zandi R, Kuhlman TE. Synthesis, insertion, and characterization of SARS-CoV-2 membrane protein within lipid bilayers. SCIENCE ADVANCES 2024; 10:eadm7030. [PMID: 38416838 PMCID: PMC10901468 DOI: 10.1126/sciadv.adm7030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 01/25/2024] [Indexed: 03/01/2024]
Abstract
Throughout history, coronaviruses have posed challenges to both public health and the global economy; nevertheless, methods to combat them remain rudimentary, primarily due to the absence of experiments to understand the function of various viral components. Among these, membrane (M) proteins are one of the most elusive because of their small size and challenges with expression. Here, we report the development of an expression system to produce tens to hundreds of milligrams of M protein per liter of Escherichia coli culture. These large yields render many previously inaccessible structural and biophysical experiments feasible. Using cryo-electron microscopy and atomic force microscopy, we image and characterize individual membrane-incorporated M protein dimers and discover membrane thinning in the vicinity, which we validated with molecular dynamics simulations. Our results suggest that the resulting line tension, along with predicted induction of local membrane curvature, could ultimately drive viral assembly and budding.
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Affiliation(s)
- Yuanzhong Zhang
- Department of Physics and Astronomy, University of California, Riverside, Riverside, CA 92521, USA
| | - Sara Anbir
- Biophysics Program, University of California, Riverside, Riverside, CA 92521, USA
| | - Joseph McTiernan
- Department of Physics, University of California, Merced, Merced, CA 95340, USA
| | - Siyu Li
- Department of Physics and Astronomy, University of California, Riverside, Riverside, CA 92521, USA
| | - Michael Worcester
- Department of Physics and Astronomy, University of California, Riverside, Riverside, CA 92521, USA
| | - Pratyasha Mishra
- Department of Biochemistry, University of California, Riverside, Riverside, CA 92521, USA
| | - Michael E. Colvin
- Department of Chemistry and Biochemistry, University of California, Merced, Merced, CA 95340, USA
| | - Ajay Gopinathan
- Department of Physics, University of California, Merced, Merced, CA 95340, USA
| | - Umar Mohideen
- Department of Physics and Astronomy, University of California, Riverside, Riverside, CA 92521, USA
- Biophysics Program, University of California, Riverside, Riverside, CA 92521, USA
| | - Roya Zandi
- Department of Physics and Astronomy, University of California, Riverside, Riverside, CA 92521, USA
- Biophysics Program, University of California, Riverside, Riverside, CA 92521, USA
| | - Thomas E. Kuhlman
- Department of Physics and Astronomy, University of California, Riverside, Riverside, CA 92521, USA
- Biophysics Program, University of California, Riverside, Riverside, CA 92521, USA
- Microbiology Program, University of California, Riverside, Riverside, CA 92521, USA
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4
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Coshic K, Maffeo C, Winogradoff D, Aksimentiev A. The structure and physical properties of a packaged bacteriophage particle. Nature 2024; 627:905-914. [PMID: 38448589 PMCID: PMC11196859 DOI: 10.1038/s41586-024-07150-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 02/01/2024] [Indexed: 03/08/2024]
Abstract
A string of nucleotides confined within a protein capsid contains all the instructions necessary to make a functional virus particle, a virion. Although the structure of the protein capsid is known for many virus species1,2, the three-dimensional organization of viral genomes has mostly eluded experimental probes3,4. Here we report all-atom structural models of an HK97 virion5, including its entire 39,732 base pair genome, obtained through multiresolution simulations. Mimicking the action of a packaging motor6, the genome was gradually loaded into the capsid. The structure of the packaged capsid was then refined through simulations of increasing resolution, which produced a 26 million atom model of the complete virion, including water and ions confined within the capsid. DNA packaging occurs through a loop extrusion mechanism7 that produces globally different configurations of the packaged genome and gives each viral particle individual traits. Multiple microsecond-long all-atom simulations characterized the effect of the packaged genome on capsid structure, internal pressure, electrostatics and diffusion of water, ions and DNA, and revealed the structural imprints of the capsid onto the genome. Our approach can be generalized to obtain complete all-atom structural models of other virus species, thereby potentially revealing new drug targets at the genome-capsid interface.
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Affiliation(s)
- Kush Coshic
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Christopher Maffeo
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - David Winogradoff
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Aleksei Aksimentiev
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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5
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Christians LF, Halingstad EV, Kram E, Okolovitch EM, Pak AJ. Formalizing Coarse-Grained Representations of Anisotropic Interactions at Multimeric Protein Interfaces Using Virtual Sites. J Phys Chem B 2024; 128:1394-1406. [PMID: 38316012 DOI: 10.1021/acs.jpcb.3c07023] [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: 02/07/2024]
Abstract
Molecular simulations of biomacromolecules that assemble into multimeric complexes remain a challenge due to computationally inaccessible length and time scales. Low-resolution and implicit-solvent coarse-grained modeling approaches using traditional nonbonded interactions (both pairwise and spherically isotropic) have been able to partially address this gap. However, these models may fail to capture the complex anisotropic interactions present at macromolecular interfaces unless higher-order interaction potentials are incorporated at the expense of the computational cost. In this work, we introduce an alternate and systematic approach to represent directional interactions at protein-protein interfaces by using virtual sites restricted to pairwise interactions. We show that virtual site interaction parameters can be optimized within a relative entropy minimization framework by using only information from known statistics between coarse-grained sites. We compare our virtual site models to traditional coarse-grained models using two case studies of multimeric protein assemblies and find that the virtual site models predict pairwise correlations with higher fidelity and, more importantly, assembly behavior that is morphologically consistent with experiments. Our study underscores the importance of anisotropic interaction representations and paves the way for more accurate yet computationally efficient coarse-grained simulations of macromolecular assembly in future research.
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Affiliation(s)
- Luc F Christians
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Ethan V Halingstad
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Emiel Kram
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Evan M Okolovitch
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Alexander J Pak
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
- Quantitative Biosciences and Engineering Program, Colorado School of Mines, Golden, Colorado 80401, United States
- Materials Science Program, Colorado School of Mines, Golden, Colorado 80401, United States
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6
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Wei WS, Trubiano A, Sigl C, Paquay S, Dietz H, Hagan MF, Fraden S. Hierarchical assembly is more robust than egalitarian assembly in synthetic capsids. Proc Natl Acad Sci U S A 2024; 121:e2312775121. [PMID: 38324570 PMCID: PMC10873614 DOI: 10.1073/pnas.2312775121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 12/07/2023] [Indexed: 02/09/2024] Open
Abstract
Self-assembly of complex and functional materials remains a grand challenge in soft material science. Efficient assembly depends on a delicate balance between thermodynamic and kinetic effects, requiring fine-tuning affinities and concentrations of subunits. By contrast, we introduce an assembly paradigm that allows large error-tolerance in the subunit affinity and helps avoid kinetic traps. Our combined experimental and computational approach uses a model system of triangular subunits programmed to assemble into T = 3 icosahedral capsids comprising 60 units. The experimental platform uses DNA origami to create monodisperse colloids whose three-dimensional geometry is controlled to nanometer precision, with two distinct bonds whose affinities are controlled to kBT precision, quantified in situ by static light scattering. The computational model uses a coarse-grained representation of subunits, short-ranged potentials, and Langevin dynamics. Experimental observations and modeling reveal that when the bond affinities are unequal, two distinct hierarchical assembly pathways occur, in which the subunits first form dimers in one case and pentamers in another. These hierarchical pathways produce complete capsids faster and are more robust against affinity variation than egalitarian pathways, in which all binding sites have equal strengths. This finding suggests that hierarchical assembly may be a general engineering principle for optimizing self-assembly of complex target structures.
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Affiliation(s)
- Wei-Shao Wei
- Martin A. Fisher School of Physics, Brandeis University, Waltham, MA02453
- Materials Research Science and Engineering Center, Brandeis University, Waltham, MA02453
| | - Anthony Trubiano
- Martin A. Fisher School of Physics, Brandeis University, Waltham, MA02453
- Materials Research Science and Engineering Center, Brandeis University, Waltham, MA02453
| | - Christian Sigl
- Laboratory for Biomolecular Nanotechnology, Department of Physics, Technical University of Munich, Garching85748, Germany
- Munich Institute of Biomedical Engineering, Technical University of Munich, Garching85748, Germany
| | - Stefan Paquay
- Martin A. Fisher School of Physics, Brandeis University, Waltham, MA02453
- Materials Research Science and Engineering Center, Brandeis University, Waltham, MA02453
| | - Hendrik Dietz
- Laboratory for Biomolecular Nanotechnology, Department of Physics, Technical University of Munich, Garching85748, Germany
- Munich Institute of Biomedical Engineering, Technical University of Munich, Garching85748, Germany
| | - Michael F. Hagan
- Martin A. Fisher School of Physics, Brandeis University, Waltham, MA02453
- Materials Research Science and Engineering Center, Brandeis University, Waltham, MA02453
| | - Seth Fraden
- Martin A. Fisher School of Physics, Brandeis University, Waltham, MA02453
- Materials Research Science and Engineering Center, Brandeis University, Waltham, MA02453
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7
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Williams LA, Neophytou A, Garmann RF, Chakrabarti D, Manoharan VN. Effect of coat-protein concentration on the self-assembly of bacteriophage MS2 capsids around RNA. NANOSCALE 2024; 16:3121-3132. [PMID: 38258446 DOI: 10.1039/d3nr03292b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Self-assembly is a vital part of the life cycle of certain icosahedral RNA viruses. Furthermore, the assembly process can be harnessed to make icosahedral virus-like particles (VLPs) from coat protein and RNA in vitro. Although much previous work has explored the effects of RNA-protein interactions on the assembly products, relatively little research has explored the effects of coat-protein concentration. We mix coat protein and RNA from bacteriophage MS2, and we use a combination of gel electrophoresis, dynamic light scattering, and transmission electron microscopy to investigate the assembly products. We show that with increasing coat-protein concentration, the products transition from well-formed MS2 VLPs to "monster" particles consisting of multiple partial capsids to RNA-protein condensates consisting of large networks of RNA and partially assembled capsids. We argue that the transition from well-formed to monster particles arises because the assembly follows a nucleation-and-growth pathway in which the nucleation rate depends sensitively on the coat-protein concentration, such that at high protein concentrations, multiple nuclei can form on each RNA strand. To understand the formation of the condensates, which occurs at even higher coat-protein concentrations, we use Monte Carlo simulations with coarse-grained models of capsomers and RNA. These simulations suggest that the formation of condensates occurs by the adsorption of protein to the RNA followed by the assembly of capsids. Multiple RNA molecules can become trapped when a capsid grows from capsomers attached to two different RNA molecules or when excess protein bridges together growing capsids on different RNA molecules. Our results provide insight into an important biophysical process and could inform design rules for making VLPs for various applications.
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Affiliation(s)
- LaNell A Williams
- Department of Physics, Harvard University, Cambridge, MA 02138, USA.
| | - Andreas Neophytou
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Rees F Garmann
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA 92182, USA
- Viral Information Institute, San Diego State University, San Diego, CA 92182, USA
| | | | - Vinothan N Manoharan
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
- Department of Physics, Harvard University, Cambridge, MA 02138, USA.
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8
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Asor R, Singaram SW, Levi-Kalisman Y, Hagan MF, Raviv U. Effect of ionic strength on the assembly of simian vacuolating virus capsid protein around poly(styrene sulfonate). THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2023; 46:107. [PMID: 37917241 DOI: 10.1140/epje/s10189-023-00363-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 10/09/2023] [Indexed: 11/04/2023]
Abstract
Virus-like particles (VLPs) are noninfectious nanocapsules that can be used for drug delivery or vaccine applications. VLPs can be assembled from virus capsid proteins around a condensing agent, such as RNA, DNA, or a charged polymer. Electrostatic interactions play an important role in the assembly reaction. VLPs assemble from many copies of capsid protein, with a combinatorial number of intermediates. Hence, the mechanism of the reaction is poorly understood. In this paper, we combined solution small-angle X-ray scattering (SAXS), cryo-transmission electron microscopy (TEM), and computational modeling to determine the effect of ionic strength on the assembly of Simian Vacuolating Virus 40 (SV40)-like particles. We mixed poly(styrene sulfonate) with SV40 capsid protein pentamers at different ionic strengths. We then characterized the assembly product by SAXS and cryo-TEM. To analyze the data, we performed Langevin dynamics simulations using a coarse-grained model that revealed incomplete, asymmetric VLP structures consistent with the experimental data. We found that close to physiological ionic strength, [Formula: see text] VLPs coexisted with VP1 pentamers. At lower or higher ionic strengths, incomplete particles coexisted with pentamers and [Formula: see text] particles. Including the simulated structures was essential to explain the SAXS data in a manner that is consistent with the cryo-TEM images.
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Affiliation(s)
- Roi Asor
- Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, 9190401, Jerusalem, Israel
| | - Surendra W Singaram
- Department of Physics, Brandeis University, 415 South Street, Waltham, 02453, MA, USA
| | - Yael Levi-Kalisman
- Institute of Life Sciences and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, 9190401, Jerusalem, Israel
| | - Michael F Hagan
- Department of Physics, Brandeis University, 415 South Street, Waltham, 02453, MA, USA.
| | - Uri Raviv
- Institute of Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, 9190401, Jerusalem, Israel.
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9
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Waltmann C, Kennedy NW, Mills CE, Roth EW, Ikonomova SP, Tullman-Ercek D, Olvera de la Cruz M. Kinetic Growth of Multicomponent Microcompartment Shells. ACS NANO 2023; 17:15751-15762. [PMID: 37552700 DOI: 10.1021/acsnano.3c03353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/10/2023]
Abstract
An important goal of systems and synthetic biology is to produce high value chemical species in large quantities. Microcompartments, which are protein nanoshells encapsulating catalytic enzyme cargo, could potentially function as tunable nanobioreactors inside and outside cells to generate these high value species. Modifying the morphology of microcompartments through genetic engineering of shell proteins is one viable strategy to tune cofactor and metabolite access to encapsulated enzymes. However, this is a difficult task without understanding how changing interactions between the many different types of shell proteins and enzymes affect microcompartment assembly and shape. Here, we use multiscale molecular dynamics and experimental data to describe assembly pathways available to microcompartments composed of multiple types of shell proteins with varied interactions. As the average interaction between the enzyme cargo and the multiple types of shell proteins is weakened, the shell assembly pathway transitions from (i) nucleating on the enzyme cargo to (ii) nucleating in the bulk and then binding the cargo as it grows to (iii) an empty shell. Atomistic simulations and experiments using the 1,2-propanediol utilization microcompartment system demonstrate that shell protein interactions are highly varied and consistent with our multicomponent, coarse-grained model. Furthermore, our results suggest that intrinsic bending angles control the size of these microcompartments. Overall, our simulations and experiments provide guidance to control microcomparmtent size and assembly by modulating the interactions between shell proteins.
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Affiliation(s)
- Curt Waltmann
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Nolan W Kennedy
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, Illinois 60208, United States
| | - Carolyn E Mills
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Eric W Roth
- Northwestern University Atomic and Nanoscale Characterization Experimentation Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Svetlana P Ikonomova
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Danielle Tullman-Ercek
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Monica Olvera de la Cruz
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
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10
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Lynch D, Pavlova A, Fan Z, Gumbart JC. Understanding Virus Structure and Dynamics through Molecular Simulations. J Chem Theory Comput 2023; 19:3025-3036. [PMID: 37192279 PMCID: PMC10269348 DOI: 10.1021/acs.jctc.3c00116] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Indexed: 05/18/2023]
Abstract
Viral outbreaks remain a serious threat to human and animal populations and motivate the continued development of antiviral drugs and vaccines, which in turn benefits from a detailed understanding of both viral structure and dynamics. While great strides have been made in characterizing these systems experimentally, molecular simulations have proven to be an essential, complementary approach. In this work, we review the contributions of molecular simulations to the understanding of viral structure, functional dynamics, and processes related to the viral life cycle. Approaches ranging from coarse-grained to all-atom representations are discussed, including current efforts at modeling complete viral systems. Overall, this review demonstrates that computational virology plays an essential role in understanding these systems.
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Affiliation(s)
- Diane
L. Lynch
- School
of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Anna Pavlova
- School
of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Zixing Fan
- Interdisciplinary
Bioengineering Graduate Program, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - James C. Gumbart
- School
of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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11
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Self-assembly of dengue virus empty capsid-like particles in solution. iScience 2023; 26:106197. [PMID: 36890794 PMCID: PMC9986514 DOI: 10.1016/j.isci.2023.106197] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 09/11/2022] [Accepted: 02/08/2023] [Indexed: 02/17/2023] Open
Abstract
Nucleocapsid (NC) assembly is an essential step of the virus replication cycle. It ensures genome protection and transmission among hosts. Flaviviruses are human viruses for which envelope structure is well known, whereas no information on NC organization is available. Here we designed a dengue virus capsid protein (DENVC) mutant in which a highly positive spot conferred by arginine 85 in α4-helix was replaced by a cysteine residue, simultaneously removing the positive charge and restricting the intermolecular motion through the formation of a disulfide cross-link. We showed that the mutant self-assembles into capsid-like particles (CLP) in solution without nucleic acids. Using biophysical techniques, we investigated capsid assembly thermodynamics, showing that an efficient assembly is related to an increased DENVC stability due to α4/α4' motion restriction. To our knowledge, this is the first time that flaviviruses' empty capsid assembly is obtained in solution, revealing the R85C mutant as a powerful tool to understand the NC assembly mechanism.
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12
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A binary interaction map between turnip mosaic virus and Arabidopsis thaliana proteomes. Commun Biol 2023; 6:28. [PMID: 36631662 PMCID: PMC9834402 DOI: 10.1038/s42003-023-04427-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 01/05/2023] [Indexed: 01/13/2023] Open
Abstract
Viruses are obligate intracellular parasites that have co-evolved with their hosts to establish an intricate network of protein-protein interactions. Here, we followed a high-throughput yeast two-hybrid screening to identify 378 novel protein-protein interactions between turnip mosaic virus (TuMV) and its natural host Arabidopsis thaliana. We identified the RNA-dependent RNA polymerase NIb as the viral protein with the largest number of contacts, including key salicylic acid-dependent transcription regulators. We verified a subset of 25 interactions in planta by bimolecular fluorescence complementation assays. We then constructed and analyzed a network comprising 399 TuMV-A. thaliana interactions together with intravirus and intrahost connections. In particular, we found that the host proteins targeted by TuMV are enriched in different aspects of plant responses to infections, are more connected and have an increased capacity to spread information throughout the cell proteome, display higher expression levels, and have been subject to stronger purifying selection than expected by chance. The proviral or antiviral role of ten host proteins was validated by characterizing the infection dynamics in the corresponding mutant plants, supporting a proviral role for the transcriptional regulator TGA1. Comparison with similar studies with animal viruses, highlights shared fundamental features in their mode of action.
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13
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Jin J, Pak AJ, Durumeric AEP, Loose TD, Voth GA. Bottom-up Coarse-Graining: Principles and Perspectives. J Chem Theory Comput 2022; 18:5759-5791. [PMID: 36070494 PMCID: PMC9558379 DOI: 10.1021/acs.jctc.2c00643] [Citation(s) in RCA: 80] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Indexed: 01/14/2023]
Abstract
Large-scale computational molecular models provide scientists a means to investigate the effect of microscopic details on emergent mesoscopic behavior. Elucidating the relationship between variations on the molecular scale and macroscopic observable properties facilitates an understanding of the molecular interactions driving the properties of real world materials and complex systems (e.g., those found in biology, chemistry, and materials science). As a result, discovering an explicit, systematic connection between microscopic nature and emergent mesoscopic behavior is a fundamental goal for this type of investigation. The molecular forces critical to driving the behavior of complex heterogeneous systems are often unclear. More problematically, simulations of representative model systems are often prohibitively expensive from both spatial and temporal perspectives, impeding straightforward investigations over possible hypotheses characterizing molecular behavior. While the reduction in resolution of a study, such as moving from an atomistic simulation to that of the resolution of large coarse-grained (CG) groups of atoms, can partially ameliorate the cost of individual simulations, the relationship between the proposed microscopic details and this intermediate resolution is nontrivial and presents new obstacles to study. Small portions of these complex systems can be realistically simulated. Alone, these smaller simulations likely do not provide insight into collectively emergent behavior. However, by proposing that the driving forces in both smaller and larger systems (containing many related copies of the smaller system) have an explicit connection, systematic bottom-up CG techniques can be used to transfer CG hypotheses discovered using a smaller scale system to a larger system of primary interest. The proposed connection between different CG systems is prescribed by (i) the CG representation (mapping) and (ii) the functional form and parameters used to represent the CG energetics, which approximate potentials of mean force (PMFs). As a result, the design of CG methods that facilitate a variety of physically relevant representations, approximations, and force fields is critical to moving the frontier of systematic CG forward. Crucially, the proposed connection between the system used for parametrization and the system of interest is orthogonal to the optimization used to approximate the potential of mean force present in all systematic CG methods. The empirical efficacy of machine learning techniques on a variety of tasks provides strong motivation to consider these approaches for approximating the PMF and analyzing these approximations.
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Affiliation(s)
- Jaehyeok Jin
- Department of Chemistry,
Chicago Center for Theoretical Chemistry, Institute for Biophysical
Dynamics, and James Franck Institute, The
University of Chicago, Chicago, Illinois 60637, United States
| | - Alexander J. Pak
- Department of Chemistry,
Chicago Center for Theoretical Chemistry, Institute for Biophysical
Dynamics, and James Franck Institute, The
University of Chicago, Chicago, Illinois 60637, United States
| | - Aleksander E. P. Durumeric
- Department of Chemistry,
Chicago Center for Theoretical Chemistry, Institute for Biophysical
Dynamics, and James Franck Institute, The
University of Chicago, Chicago, Illinois 60637, United States
| | - Timothy D. Loose
- Department of Chemistry,
Chicago Center for Theoretical Chemistry, Institute for Biophysical
Dynamics, and James Franck Institute, The
University of Chicago, Chicago, Illinois 60637, United States
| | - Gregory A. Voth
- Department of Chemistry,
Chicago Center for Theoretical Chemistry, Institute for Biophysical
Dynamics, and James Franck Institute, The
University of Chicago, Chicago, Illinois 60637, United States
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14
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Li S, Zandi R. Biophysical Modeling of SARS-CoV-2 Assembly: Genome Condensation and Budding. Viruses 2022; 14:2089. [PMID: 36298645 PMCID: PMC9611094 DOI: 10.3390/v14102089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/12/2022] [Accepted: 09/16/2022] [Indexed: 11/18/2022] Open
Abstract
The COVID-19 pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has spurred unprecedented and concerted worldwide research to curtail and eradicate this pathogen. SARS-CoV-2 has four structural proteins: Envelope (E), Membrane (M), Nucleocapsid (N), and Spike (S), which self-assemble along with its RNA into the infectious virus by budding from intracellular lipid membranes. In this paper, we develop a model to explore the mechanisms of RNA condensation by structural proteins, protein oligomerization and cellular membrane-protein interactions that control the budding process and the ultimate virus structure. Using molecular dynamics simulations, we have deciphered how the positively charged N proteins interact and condense the very long genomic RNA resulting in its packaging by a lipid envelope decorated with structural proteins inside a host cell. Furthermore, considering the length of RNA and the size of the virus, we find that the intrinsic curvature of M proteins is essential for virus budding. While most current research has focused on the S protein, which is responsible for viral entry, and it has been motivated by the need to develop efficacious vaccines, the development of resistance through mutations in this crucial protein makes it essential to elucidate the details of the viral life cycle to identify other drug targets for future therapy. Our simulations will provide insight into the viral life cycle through the assembly of viral particles de novo and potentially identify therapeutic targets for future drug development.
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Affiliation(s)
- Siyu Li
- Songshan Lake Materials Laboratory, Dongguan 523808, China
| | - Roya Zandi
- Department of Physics and Astronomy, University of California Riverside, Riverside, CA 92521, USA
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15
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Tsidilkovski L, Mohajerani F, Hagan MF. Microcompartment assembly around multicomponent fluid cargoes. J Chem Phys 2022; 156:245104. [PMID: 35778087 PMCID: PMC9249432 DOI: 10.1063/5.0089556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This article describes dynamical simulations of the assembly of an icosahedral protein shell around a bicomponent fluid cargo. Our simulations are motivated by bacterial microcompartments, which are protein shells found in bacteria that assemble around a complex of enzymes and other components involved in certain metabolic processes. The simulations demonstrate that the relative interaction strengths among the different cargo species play a key role in determining the amount of each species that is encapsulated, their spatial organization, and the nature of the shell assembly pathways. However, the shell protein–shell protein and shell protein–cargo component interactions that help drive assembly and encapsulation also influence cargo composition within certain parameter regimes. These behaviors are governed by a combination of thermodynamic and kinetic effects. In addition to elucidating how natural microcompartments encapsulate multiple components involved within reaction cascades, these results have implications for efforts in synthetic biology to colocalize alternative sets of molecules within microcompartments to accelerate specific reactions. More broadly, the results suggest that coupling between self-assembly and multicomponent liquid–liquid phase separation may play a role in the organization of the cellular cytoplasm.
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Affiliation(s)
- Lev Tsidilkovski
- Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts 02453, USA
| | - Farzaneh Mohajerani
- Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts 02453, USA
| | - Michael F Hagan
- Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts 02453, USA
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16
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Harati Taji Z, Bielytskyi P, Shein M, Sani MA, Seitz S, Schütz AK. Transient RNA Interactions Leave a Covalent Imprint on a Viral Capsid Protein. J Am Chem Soc 2022; 144:8536-8550. [PMID: 35512333 PMCID: PMC9121876 DOI: 10.1021/jacs.1c12439] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The hepatitis B virus (HBV) is the leading cause of persistent liver infections. Its DNA-based genome is synthesized through reverse transcription of an RNA template inside the assembled capsid shell. In addition to the structured assembly domain, the capsid protein harbors a C-terminal extension that mediates both the enclosure of RNA during capsid assembly and the nuclear entry of the capsid during infection. The arginine-rich motifs within this extension, though common to many viruses, have largely escaped atomic-scale investigation. Here, we leverage solution and solid-state nuclear magnetic resonance spectroscopy at ambient and cryogenic temperatures, under dynamic nuclear polarization signal enhancement, to investigate the organization of the genome within the capsid. Transient interactions with phosphate groups of the RNA backbone confine the arginine-rich motifs to the interior capsid space. While no secondary structure is induced in the C-terminal extension, interactions with RNA counteract the formation of a disulfide bond, which covalently tethers this peptide arm onto the inner capsid surface. Electrostatic and covalent contributions thus compete in the spatial regulation of capsid architecture. This disulfide switch represents a coupling mechanism between the structured assembly domain of the capsid and the enclosed nucleic acids. In particular, it enables the redox-dependent regulation of the exposure of the C-terminal extension on the capsid surface, which is required for nuclear uptake of the capsid. Phylogenetic analysis of capsid proteins from hepadnaviruses points toward a function of this switch in the persistence of HBV infections.
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Affiliation(s)
- Zahra Harati Taji
- Bavarian NMR Center, Department of Chemistry, Technical University of Munich, Garching 85748, Germany.,Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg 85764, Germany
| | - Pavlo Bielytskyi
- Bavarian NMR Center, Department of Chemistry, Technical University of Munich, Garching 85748, Germany.,Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg 85764, Germany
| | - Mikhail Shein
- Bavarian NMR Center, Department of Chemistry, Technical University of Munich, Garching 85748, Germany.,Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg 85764, Germany
| | - Marc-Antoine Sani
- School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Stefan Seitz
- Department of Infectious Diseases, Molecular Virology, University of Heidelberg, Heidelberg 69120, Germany.,Division of Virus-Associated Carcinogenesis (F170), German Cancer Research Center (DKFZ), Heidelberg 69120, Germany
| | - Anne K Schütz
- Bavarian NMR Center, Department of Chemistry, Technical University of Munich, Garching 85748, Germany.,Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg 85764, Germany
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17
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Sukeník L, Mukhamedova L, Procházková M, Škubník K, Plevka P, Vácha R. Cargo Release from Nonenveloped Viruses and Virus-like Nanoparticles: Capsid Rupture or Pore Formation. ACS NANO 2021; 15:19233-19243. [PMID: 34881874 DOI: 10.1021/acsnano.1c04814] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Virus-like nanoparticles are protein shells similar to wild-type viruses, and both aim to deliver their content into a cell. Unfortunately, the release mechanism of their cargo/genome remains elusive. Pores on the symmetry axes were proposed to enable the slow release of the viral genome. In contrast, cryo-EM images showed that capsids of nonenveloped RNA viruses can crack open and rapidly release the genome. We combined in vitro cryo-EM observations of the genome release of three viruses with coarse-grained simulations of generic virus-like nanoparticles to investigate the cargo/genome release pathways. Simulations provided details on both slow and rapid release pathways, including the success rates of individual releases. Moreover, the simulated structures from the rapid release pathway were in agreement with the experiment. Slow release occurred when interactions between capsid subunits were long-ranged, and the cargo/genome was noncompact. In contrast, rapid release was preferred when the interaction range was short and/or the cargo/genome was compact. These findings indicate a design strategy of virus-like nanoparticles for drug delivery.
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Affiliation(s)
- Lukáš Sukeník
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
- Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská 267/2, 611 37 Brno, Czech Republic
| | - Liya Mukhamedova
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Michaela Procházková
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Karel Škubník
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Pavel Plevka
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Robert Vácha
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
- Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská 267/2, 611 37 Brno, Czech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
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18
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Solé R, Sardanyés J, Elena SF. Phase transitions in virology. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2021; 84:115901. [PMID: 34584031 DOI: 10.1088/1361-6633/ac2ab0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 09/28/2021] [Indexed: 06/13/2023]
Abstract
Viruses have established relationships with almost every other living organism on Earth and at all levels of biological organization: from other viruses up to entire ecosystems. In most cases, they peacefully coexist with their hosts, but in most relevant cases, they parasitize them and induce diseases and pandemics, such as the AIDS and the most recent avian influenza and COVID-19 pandemic events, causing a huge impact on health, society, and economy. Viruses play an essential role in shaping the eco-evolutionary dynamics of their hosts, and have been also involved in some of the major evolutionary innovations either by working as vectors of genetic information or by being themselves coopted by the host into their genomes. Viruses can be studied at different levels of biological organization, from the molecular mechanisms of genome replication, gene expression and encapsidation, to global pandemics. All these levels are different and yet connected through the presence of threshold conditions allowing for the formation of a capsid, the loss of genetic information or epidemic spreading. These thresholds, as occurs with temperature separating phases in a liquid, define sharp qualitative types of behaviour. Thesephase transitionsare very well known in physics. They have been studied by means of simple, but powerful models able to capture their essential properties, allowing us to better understand them. Can the physics of phase transitions be an inspiration for our understanding of viral dynamics at different scales? Here we review well-known mathematical models of transition phenomena in virology. We suggest that the advantages of abstract, simplified pictures used in physics are also the key to properly understanding the origins and evolution of complexity in viruses. By means of several examples, we explore this multilevel landscape and how minimal models provide deep insights into a diverse array of problems. The relevance of these transitions in connecting dynamical patterns across scales and their evolutionary and clinical implications are outlined.
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Affiliation(s)
- Ricard Solé
- ICREA-Complex Systems Lab, Universitat Pompeu Fabra-PRBB, Dr Aiguader 80, 08003 Barcelona, Spain
- Institut de Biologia Evolutiva, CSIC-Universitat Pompeu Fabra, Passeig Maritim de la Barceloneta 37, 08003 Barcelona, Spain
- Santa Fe Institute, 1399 Hyde Park Road, Santa Fe NM 87501, United States of America
| | - Josep Sardanyés
- Centre de Recerca Matemàtica (CRM), Edifici C, Campus de Bellaterra, Cerdanyola del Vallès, 08193 Barcelona, Spain
- Dynamical Systems and Computational Virology, CSIC Associated Unit, Institute for Integrative Systems Biology (I2SysBio)-CRM, Spain
| | - Santiago F Elena
- Santa Fe Institute, 1399 Hyde Park Road, Santa Fe NM 87501, United States of America
- Evolutionary Systems Virology Lab (I2SysBio), CSIC-Universitat de València, Catedrático Agustín Escardino 9, Paterna, 46980 València, Spain
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19
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Jack A, Ferro LS, Trnka MJ, Wehri E, Nadgir A, Nguyenla X, Fox D, Costa K, Stanley S, Schaletzky J, Yildiz A. SARS-CoV-2 nucleocapsid protein forms condensates with viral genomic RNA. PLoS Biol 2021; 19:e3001425. [PMID: 34634033 PMCID: PMC8553124 DOI: 10.1371/journal.pbio.3001425] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 10/28/2021] [Accepted: 09/28/2021] [Indexed: 12/13/2022] Open
Abstract
The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection causes Coronavirus Disease 2019 (COVID-19), a pandemic that seriously threatens global health. SARS-CoV-2 propagates by packaging its RNA genome into membrane enclosures in host cells. The packaging of the viral genome into the nascent virion is mediated by the nucleocapsid (N) protein, but the underlying mechanism remains unclear. Here, we show that the N protein forms biomolecular condensates with viral genomic RNA both in vitro and in mammalian cells. While the N protein forms spherical assemblies with homopolymeric RNA substrates that do not form base pairing interactions, it forms asymmetric condensates with viral RNA strands. Cross-linking mass spectrometry (CLMS) identified a region that drives interactions between N proteins in condensates, and deletion of this region disrupts phase separation. We also identified small molecules that alter the size and shape of N protein condensates and inhibit the proliferation of SARS-CoV-2 in infected cells. These results suggest that the N protein may utilize biomolecular condensation to package the SARS-CoV-2 RNA genome into a viral particle.
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Affiliation(s)
- Amanda Jack
- Biophysics Graduate Group, University of California, Berkeley, California, United States of America
| | - Luke S. Ferro
- Department of Molecular and Cell Biology, University of California, Berkeley, California, United States of America
| | - Michael J. Trnka
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California, United States of America
| | - Eddie Wehri
- Center for Emerging and Neglected Diseases, University of California, Berkeley, California, United States of America
| | - Amrut Nadgir
- Physics Department, University of California, Berkeley, California, United States of America
| | - Xammy Nguyenla
- School of Public Health, Division of Infectious Diseases and Vaccinology, University of California, Berkeley, California, United States of America
| | - Douglas Fox
- School of Public Health, Division of Infectious Diseases and Vaccinology, University of California, Berkeley, California, United States of America
| | - Katelyn Costa
- Press West Illustrations, Boston, Massachusetts, United States of America
| | - Sarah Stanley
- Department of Molecular and Cell Biology, University of California, Berkeley, California, United States of America
- School of Public Health, Division of Infectious Diseases and Vaccinology, University of California, Berkeley, California, United States of America
| | - Julia Schaletzky
- Center for Emerging and Neglected Diseases, University of California, Berkeley, California, United States of America
| | - Ahmet Yildiz
- Biophysics Graduate Group, University of California, Berkeley, California, United States of America
- Department of Molecular and Cell Biology, University of California, Berkeley, California, United States of America
- Physics Department, University of California, Berkeley, California, United States of America
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20
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RNA Structures and Their Role in Selective Genome Packaging. Viruses 2021; 13:v13091788. [PMID: 34578369 PMCID: PMC8472981 DOI: 10.3390/v13091788] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/31/2021] [Accepted: 09/02/2021] [Indexed: 12/13/2022] Open
Abstract
To generate infectious viral particles, viruses must specifically select their genomic RNA from milieu that contains a complex mixture of cellular or non-genomic viral RNAs. In this review, we focus on the role of viral encoded RNA structures in genome packaging. We first discuss how packaging signals are constructed from local and long-range base pairings within viral genomes, as well as inter-molecular interactions between viral and host RNAs. Then, how genome packaging is regulated by the biophysical properties of RNA. Finally, we examine the impact of RNA packaging signals on viral evolution.
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21
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Xu C, Katyal N, Nesterova T, Perilla JR. Molecular determinants of Ebola nucleocapsid stability from molecular dynamics simulations. J Chem Phys 2021; 153:155102. [PMID: 33092380 DOI: 10.1063/5.0021491] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Ebola virus (EBOV) is a human pathogen with the ability to cause hemorrhagic fever and bleeding diathesis in hosts. The life cycle of EBOV depends on its nucleocapsid. The Ebola nucleocapsid consists of a helical assembly of nucleoproteins (NPs) encapsidating single-stranded viral RNA (ssRNA). Knowledge of the molecular determinants of Ebola nucleocapsid stability is essential for the development of therapeutics against EBOV. However, large degrees of freedom associated with the Ebola nucleocapsid helical assembly pose a computational challenge, thereby limiting the previous simulation studies to the level of monomers. In the present work, we have performed all atom molecular dynamics (MD) simulations of the helical assembly of EBOV nucleoproteins in the absence and presence of ssRNA. We found that ssRNA is essential for maintaining structural integrity of the nucleocapsid. Other molecular determinants observed to stabilize the nucleocapsid include NP-RNA and NP-NP interactions and ion distributions. Additionally, the structural and dynamical behavior of the nucleocapsid monomer depends on its position in the helical assembly. NP monomers present on the longitudinal edges of the helical tube are more exposed, flexible, and have weaker NP-NP interactions than those residing in the center. This work provides key structural features stabilizing the nucleocapsid that may serve as therapeutic targets.
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Affiliation(s)
- Chaoyi Xu
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
| | - Nidhi Katyal
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
| | - Tanya Nesterova
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
| | - Juan R Perilla
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
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22
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Chaudhari HV, Inamdar MM, Kondabagil K. Scaling relation between genome length and particle size of viruses provides insights into viral life history. iScience 2021; 24:102452. [PMID: 34113814 PMCID: PMC8169800 DOI: 10.1016/j.isci.2021.102452] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 03/23/2021] [Accepted: 04/15/2021] [Indexed: 12/12/2022] Open
Abstract
In terms of genome and particle sizes, viruses exhibit great diversity. With the discovery of several nucleocytoplasmic large DNA viruses (NCLDVs) and jumbo phages, the relationship between particle and genome sizes has emerged as an important criterion for understanding virus evolution. We use allometric scaling of capsid volume with the genome length of different groups of viruses to shed light on its relationship with virus life history. The allometric exponents for icosahedral dsDNA bacteriophages and NCDLVs were found to be 1 and 2, respectively, indicating that with increasing capsid size DNA packaging density remains the same in bacteriophages but decreases for NCLDVs. We argue that the exponents are largely shaped by their entry mechanism and capsid mechanical stability. We further show that these allometric size parameters are also intricately linked to the relative energy costs of translation and replication in viruses and can have further implications on viral life history. Capsid and genome size allometric exponent gives insights into viral life history The allometric exponent of NCLDVs is almost twice that of bacteriophages The exponent is largely shaped by the viral entry mechanism and capsid stability The relaxed genome size constraint allows large viruses to evolve greater autonomy
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Affiliation(s)
- Harshali V Chaudhari
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Mandar M Inamdar
- Department of Civil Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Kiran Kondabagil
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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23
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Jana AK, May ER. Atomistic dynamics of a viral infection process: Release of membrane lytic peptides from a non-enveloped virus. SCIENCE ADVANCES 2021; 7:7/16/eabe1761. [PMID: 33853772 PMCID: PMC8046363 DOI: 10.1126/sciadv.abe1761] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 02/23/2021] [Indexed: 05/13/2023]
Abstract
Molecular simulations have played an instrumental role in uncovering the structural dynamics and physical properties of virus capsids. In this work, we move beyond equilibrium physicochemical characterization of a virus system to study a stage of the infection process that is required for viral proliferation. Despite many biochemical and functional studies, the molecular mechanism of host cell entry by non-enveloped viruses remains largely unresolved. Flock House virus (FHV) is a model system for non-enveloped viruses and is the subject of the current study. FHV infects through the acid-dependent endocytic pathway, where low pH triggers externalization of membrane-disrupting (γ) peptides from the capsid interior. Using all-atom equilibrium and enhanced sampling simulations, the mechanism and energetics of γ peptide liberation and the effect of pH on this process are investigated. Our computations agree with experimental findings and reveal nanoscopic details regarding the pH control mechanism, which are not readily accessible in experiments.
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Affiliation(s)
- Asis K Jana
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Eric R May
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA.
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24
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Jack A, Ferro LS, Trnka MJ, Wehri E, Nadgir A, Nguyenla X, Costa K, Stanley S, Schaletzky J, Yildiz A. SARS-CoV-2 nucleocapsid protein forms condensates with viral genomic RNA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2021:2020.09.14.295824. [PMID: 32995779 PMCID: PMC7523105 DOI: 10.1101/2020.09.14.295824] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection causes COVID-19, a pandemic that seriously threatens global health. SARS-CoV-2 propagates by packaging its RNA genome into membrane enclosures in host cells. The packaging of the viral genome into the nascent virion is mediated by the nucleocapsid (N) protein, but the underlying mechanism remains unclear. Here, we show that the N protein forms biomolecular condensates with viral genomic RNA both in vitro and in mammalian cells. Phase separation is driven, in part, by hydrophobic and electrostatic interactions. While the N protein forms spherical assemblies with unstructured RNA, it forms asymmetric condensates with viral RNA strands that contain secondary structure elements. Cross-linking mass spectrometry identified a region that forms interactions between N proteins in condensates, and truncation of this region disrupts phase separation. We also identified small molecules that alter the formation of N protein condensates. These results suggest that the N protein may utilize biomolecular condensation to package the SARS-CoV-2 RNA genome into a viral particle.
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Affiliation(s)
- Amanda Jack
- Biophysics Graduate Group, University of California, Berkeley CA
| | - Luke S. Ferro
- Department of Molecular and Cellular Biology, University of California, Berkeley CA
| | - Michael J. Trnka
- Department of Pharmaceutical Chemistry, University of California, San Francisco CA
| | - Eddie Wehri
- Center for Emerging and Neglected Diseases, University of California, Berkeley CA
| | - Amrut Nadgir
- Physics Department, University of California, Berkeley CA
| | - Xammy Nguyenla
- School of Public Health, Division of Infectious Diseases and Vaccinology, University of California, Berkeley, CA
| | | | - Sarah Stanley
- Department of Molecular and Cellular Biology, University of California, Berkeley CA
- School of Public Health, Division of Infectious Diseases and Vaccinology, University of California, Berkeley, CA
| | - Julia Schaletzky
- Center for Emerging and Neglected Diseases, University of California, Berkeley CA
| | - Ahmet Yildiz
- Biophysics Graduate Group, University of California, Berkeley CA
- Department of Molecular and Cellular Biology, University of California, Berkeley CA
- Physics Department, University of California, Berkeley CA
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25
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Wang Y, Chai C, Khatabi B, Scheible WR, Udvardi MK, Saha MC, Kang Y, Nelson RS. An Efficient Brome mosaic virus-Based Gene Silencing Protocol for Hexaploid Wheat ( Triticum aestivum L.). FRONTIERS IN PLANT SCIENCE 2021; 12:685187. [PMID: 34220905 PMCID: PMC8253535 DOI: 10.3389/fpls.2021.685187] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 05/07/2021] [Indexed: 05/09/2023]
Abstract
Virus-induced gene silencing (VIGS) is a rapid and powerful method to evaluate gene function, especially for species like hexaploid wheat that have large, redundant genomes and are difficult and time-consuming to transform. The Brome mosaic virus (BMV)-based VIGS vector is widely used in monocotyledonous species but not wheat. Here we report the establishment of a simple and effective VIGS procedure in bread wheat using BMVCP5, the most recently improved BMV silencing vector, and wheat genes PHYTOENE DESATURASE (TaPDS) and PHOSPHATE2 (TaPHO2) as targets. Time-course experiments revealed that smaller inserts (~100 nucleotides, nt) were more stable in BMVCP5 and conferred higher silencing efficiency and longer silencing duration, compared with larger inserts. When using a 100-nt insert and a novel coleoptile inoculation method, BMVCP5 induced extensive silencing of TaPDS transcript and a visible bleaching phenotype in the 2nd to 5th systemically-infected leaves from nine to at least 28 days post inoculation (dpi). For TaPHO2, the ability of BMVCP5 to simultaneously silence all three homoeologs was demonstrated. To investigate the feasibility of BMV VIGS in wheat roots, ectopically expressed enhanced GREEN FLUORESCENT PROTEIN (eGFP) in a transgenic wheat line was targeted for silencing. Silencing of eGFP fluorescence was observed in both the maturation and elongation zones of roots. BMVCP5 mediated significant silencing of eGFP and TaPHO2 mRNA expression in roots at 14 and 21 dpi, and TaPHO2 silencing led to the doubling of inorganic phosphate concentration in the 2nd through 4th systemic leaves. All 54 wheat cultivars screened were susceptible to BMV infection. BMVCP5-mediated TaPDS silencing resulted in the expected bleaching phenotype in all eight cultivars examined, and decreased TaPDS transcript was detected in all three cultivars examined. This BMVCP5 VIGS technology may serve as a rapid and effective functional genomics tool for high-throughput gene function studies in aerial and root tissues and in many wheat cultivars.
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Dong Y, Li S, Zandi R. Effect of the charge distribution of virus coat proteins on the length of packaged RNAs. Phys Rev E 2020; 102:062423. [PMID: 33466113 DOI: 10.1103/physreve.102.062423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 11/17/2020] [Indexed: 01/20/2023]
Abstract
Single-stranded RNA viruses efficiently encapsulate their genome into a protein shell called the capsid. Electrostatic interactions between the positive charges in the capsid protein's N-terminal tail and the negatively charged genome have been postulated as the main driving force for virus assembly. Recent experimental results indicate that the N-terminal tail with the same number of charges and same lengths packages different amounts of RNA, which reveals that electrostatics alone cannot explain all the observed outcomes of the RNA self-assembly experiments. Using a mean-field theory, we show that the combined effect of genome configurational entropy and electrostatics can explain to some extent the amount of packaged RNA with mutant proteins where the location and number of charges on the tails are altered. Understanding the factors contributing to the virus assembly could promote the attempt to block viral infections or to build capsids for gene therapy applications.
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Affiliation(s)
- Yinan Dong
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
| | - Siyu Li
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
| | - Roya Zandi
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA
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27
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Waltmann C, Asor R, Raviv U, Olvera de la Cruz M. Assembly and Stability of Simian Virus 40 Polymorphs. ACS NANO 2020; 14:4430-4443. [PMID: 32208635 PMCID: PMC7232851 DOI: 10.1021/acsnano.9b10004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Understanding viral assembly pathways is of critical importance to biology, medicine, and nanotechology. Here, we study the assembly path of a system with various structures, the simian vacuolating virus 40 (SV40) polymorphs. We simulate the templated assembly process of VP1 pentamers, which are the constituents of SV40, into icosahedal shells made of N = 12 pentamers (T = 1). The simulations include connections formed between pentamers by C-terminal flexible lateral units, termed here "C-terminal ligands", which are shown to control assembly behavior and shell dynamics. The model also incorporates electrostatic attractions between the N-terminal peptide strands (ligands) and the negatively charged cargo, allowing for agreement with experiments of RNA templated assembly at various pH and ionic conditions. During viral assembly, pentamers bound to any template increase its effective size due to the length and flexibility of the C-terminal ligands, which can connect to other VP1 pentamers and recruit them to a partially completed capsid. All closed shells formed other than the T = 1 feature the ability to dynamically rearrange and are thus termed "pseudo-closed". The N = 13 shell can even spontaneously "self-correct" by losing a pentamer and become a T = 1 capsid when the template size fluctuates. Bound pentamers recruiting additional pentamers to dynamically rearranging capsids allow closed shells to continue growing via the pseudo-closed growth mechanism, for which experimental evidence already exists. Overall, we show that the C-terminal ligands control the dynamic assembly paths of SV40 polymorphs.
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Affiliation(s)
- Curt Waltmann
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Roi Asor
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J Safra Campus, Givat Ram, Jerusalem, 9190401, Israel
- Center for Nanoscale Science and Technology, The Hebrew University of Jerusalem, Edmond J Safra Campus, Givat Ram, Jerusalem, 9190401, Israel
| | - Uri Raviv
- Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J Safra Campus, Givat Ram, Jerusalem, 9190401, Israel
- Center for Nanoscale Science and Technology, The Hebrew University of Jerusalem, Edmond J Safra Campus, Givat Ram, Jerusalem, 9190401, Israel
| | - Monica Olvera de la Cruz
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
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van Rosmalen MGM, Kamsma D, Biebricher AS, Li C, Zlotnick A, Roos WH, Wuite GJ. Revealing in real-time a multistep assembly mechanism for SV40 virus-like particles. SCIENCE ADVANCES 2020; 6:eaaz1639. [PMID: 32494611 PMCID: PMC7159915 DOI: 10.1126/sciadv.aaz1639] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 01/09/2020] [Indexed: 05/20/2023]
Abstract
Many viruses use their genome as template for self-assembly into an infectious particle. However, this reaction remains elusive because of the transient nature of intermediate structures. To elucidate this process, optical tweezers and acoustic force spectroscopy are used to follow viral assembly in real time. Using Simian virus 40 (SV40) virus-like particles as model system, we reveal a multistep assembly mechanism. Initially, binding of VP1 pentamers to DNA leads to a significantly decreased persistence length. Moreover, the pentamers seem able to stabilize DNA loops. Next, formation of interpentamer interactions results in intermediate structures with reduced contour length. These structures stabilize into objects that permanently decrease the contour length to a degree consistent with DNA compaction in wild-type SV40. These data indicate that a multistep mechanism leads to fully assembled cross-linked SV40 particles. SV40 is studied as drug delivery system. Our insights can help optimize packaging of therapeutic agents in these particles.
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Affiliation(s)
- Mariska G. M. van Rosmalen
- Natuur- en Sterrenkunde and LaserLaB, Vrije Universiteit Amsterdam, Boelelaan 1081, 1081 HV Amsterdam, Netherlands
| | - Douwe Kamsma
- Natuur- en Sterrenkunde and LaserLaB, Vrije Universiteit Amsterdam, Boelelaan 1081, 1081 HV Amsterdam, Netherlands
| | - Andreas S. Biebricher
- Natuur- en Sterrenkunde and LaserLaB, Vrije Universiteit Amsterdam, Boelelaan 1081, 1081 HV Amsterdam, Netherlands
| | - Chenglei Li
- Department of Molecular and Cellular Biochemistry, Indiana University, 212 S Hawthorne Dr., Bloomington, IN 47405, USA
| | - Adam Zlotnick
- Department of Molecular and Cellular Biochemistry, Indiana University, 212 S Hawthorne Dr., Bloomington, IN 47405, USA
| | - Wouter H. Roos
- Moleculaire Biofysica, Zernike Instituut, Rijksuniversiteit Groningen, Nijenborgh 4, 9747 AG Groningen, Netherlands
- Corresponding author. (G.J.L.W.); (W.H.R.)
| | - Gijs J.L. Wuite
- Natuur- en Sterrenkunde and LaserLaB, Vrije Universiteit Amsterdam, Boelelaan 1081, 1081 HV Amsterdam, Netherlands
- Corresponding author. (G.J.L.W.); (W.H.R.)
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29
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Viruses with different genome types adopt a similar strategy to pack nucleic acids based on positively charged protein domains. Sci Rep 2020; 10:5470. [PMID: 32214181 PMCID: PMC7096446 DOI: 10.1038/s41598-020-62328-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 03/02/2020] [Indexed: 11/17/2022] Open
Abstract
Capsid proteins often present a positively charged arginine-rich sequence at their terminal regions, which has a fundamental role in genome packaging and particle stability for some icosahedral viruses. These sequences show little to no conservation and are structurally dynamic such that they cannot be easily detected by common sequence or structure comparisons. As a result, the occurrence and distribution of positively charged domains across the viral universe are unknown. Based on the net charge calculation of discrete protein segments, we identified proteins containing amino acid stretches with a notably high net charge (Q > + 17), which are enriched in icosahedral viruses with a distinctive bias towards arginine over lysine. We used viral particle structural data to calculate the total electrostatic charge derived from the most positively charged protein segment of capsid proteins and correlated these values with genome charges arising from the phosphates of each nucleotide. We obtained a positive correlation (r = 0.91, p-value <0001) for a group of 17 viral families, corresponding to 40% of all families with icosahedral structures described to date. These data indicated that unrelated viruses with diverse genome types adopt a common underlying mechanism for capsid assembly based on R-arms.
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30
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Panahandeh S, Li S, Marichal L, Leite Rubim R, Tresset G, Zandi R. How a Virus Circumvents Energy Barriers to Form Symmetric Shells. ACS NANO 2020; 14:3170-3180. [PMID: 32115940 DOI: 10.1021/acsnano.9b08354] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Previous self-assembly experiments on a model icosahedral plant virus have shown that, under physiological conditions, capsid proteins initially bind to the genome through an en masse mechanism and form nucleoprotein complexes in a disordered state, which raises the question as to how virions are assembled into a highly ordered structure in the host cell. Using small-angle X-ray scattering, we find out that a disorder-order transition occurs under physiological conditions upon an increase in capsid protein concentrations. Our cryo-transmission electron microscopy reveals closed spherical shells containing in vitro transcribed viral RNA even at pH 7.5, in marked contrast with the previous observations. We use Monte Carlo simulations to explain this disorder-order transition and find that, as the shell grows, the structures of disordered intermediates in which the distribution of pentamers does not belong to the icosahedral subgroups become energetically so unfavorable that the caps can easily dissociate and reassemble, overcoming the energy barriers for the formation of perfect icosahedral shells. In addition, we monitor the growth of capsids under the condition that the nucleation and growth is the dominant pathway and show that the key for the disorder-order transition in both en masse and nucleation and growth pathways lies in the strength of elastic energy compared to the other forces in the system including protein-protein interactions and the chemical potential of free subunits. Our findings explain, at least in part, why perfect virions with icosahedral order form under different conditions including physiological ones.
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Affiliation(s)
- Sanaz Panahandeh
- Department of Physics and Astronomy, University of California, Riverside, California 92521, United States
| | - Siyu Li
- Department of Physics and Astronomy, University of California, Riverside, California 92521, United States
| | - Laurent Marichal
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| | - Rafael Leite Rubim
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| | - Guillaume Tresset
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| | - Roya Zandi
- Department of Physics and Astronomy, University of California, Riverside, California 92521, United States
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31
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Buzón P, Maity S, Roos WH. Physical virology: From virus self-assembly to particle mechanics. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2020; 12:e1613. [PMID: 31960585 PMCID: PMC7317356 DOI: 10.1002/wnan.1613] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 10/01/2019] [Accepted: 12/11/2019] [Indexed: 12/19/2022]
Abstract
Viruses are highly ordered supramolecular complexes that have evolved to propagate by hijacking the host cell's machinery. Although viruses are very diverse, spreading through cells of all kingdoms of life, they share common functions and properties. Next to the general interest in virology, fundamental viral mechanisms are of growing importance in other disciplines such as biomedicine and (bio)nanotechnology. However, in order to optimally make use of viruses and virus-like particles, for instance as vehicle for targeted drug delivery or as building blocks in electronics, it is essential to understand their basic chemical and physical properties and characteristics. In this context, the number of studies addressing the mechanisms governing viral properties and processes has recently grown drastically. This review summarizes a specific part of these scientific achievements, particularly addressing physical virology approaches aimed to understand the self-assembly of viruses and the mechanical properties of viral particles. Using a physicochemical perspective, we have focused on fundamental studies providing an overview of the molecular basis governing these key aspects of viral systems. This article is categorized under: Biology-Inspired Nanomaterials > Protein and Virus-Based Structures Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.
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Affiliation(s)
- Pedro Buzón
- Moleculaire Biofysica, Zernike Instituut, Rijksuniversiteit Groningen, Groningen, The Netherlands
| | - Sourav Maity
- Moleculaire Biofysica, Zernike Instituut, Rijksuniversiteit Groningen, Groningen, The Netherlands
| | - Wouter H Roos
- Moleculaire Biofysica, Zernike Instituut, Rijksuniversiteit Groningen, Groningen, The Netherlands
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32
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Fejer SN. Minimalistic coarse-grained modeling of viral capsid assembly. COMPUTATIONAL APPROACHES FOR UNDERSTANDING DYNAMICAL SYSTEMS: PROTEIN FOLDING AND ASSEMBLY 2020; 170:405-434. [DOI: 10.1016/bs.pmbts.2019.12.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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33
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Thurm AR, Beren C, Duran-Meza AL, Knobler CM, Gelbart WM. RNA Homopolymers Form Higher-Curvature Virus-like Particles Than Do Normal-Composition RNAs. Biophys J 2019; 117:1331-1341. [PMID: 31514968 PMCID: PMC6818174 DOI: 10.1016/j.bpj.2019.08.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 06/17/2019] [Accepted: 08/07/2019] [Indexed: 11/15/2022] Open
Abstract
Unlike double-stranded DNA, single-stranded RNA can be spontaneously packaged into spherical capsids by viral capsid protein (CP) because it is a more compact and flexible polymer. Many systematic investigations of this self-assembly process have been carried out using CP from cowpea chlorotic mottle virus, with a wide range of sequences and lengths of single-stranded RNA. Among these studies are measurements of the relative packaging efficiencies of these RNAs into spherical capsids. In this work, we address a fundamental issue that has received very little attention, namely the question of the preferred curvature of the capsid formed around different RNA molecules. We show in particular that homopolymers of RNA-polyribouridylic acid and polyriboadenylic acid-form exclusively T = 2-sized (∼22-nm diameter) virus-like particles (VLPs) when mixed with cowpea chlorotic mottle virus CP, independent of their length, ranging from 500 to more than 4000 nucleotides. This is in contrast to "normal-composition" RNAs (i.e., molecules with comparable numbers of each of the four nucleotides and hence capable of developing a large amount of secondary structure because of intramolecular complementarity/basepairing); a curvature corresponding to T = 3-size (∼28 nm in diameter) is preferred for the VLPs formed with such RNAs. Our work is consistent with the preferred curvature of VLPs being a consequence of interaction of CP with RNA-in particular, the presence or absence of short RNA duplexes-and suggests that the equilibrium size of the capsid results from a trade-off between this optimum size and the cost of confinement.
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Affiliation(s)
- Abby R Thurm
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California
| | - Christian Beren
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California
| | - Ana Luisa Duran-Meza
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California
| | - Charles M Knobler
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California
| | - William M Gelbart
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California; Molecular Biology Institute, University of California, Los Angeles, California; California NanoSystems Institute, University of California, Los Angeles, California.
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34
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Marchetti M, Kamsma D, Cazares Vargas E, Hernandez García A, van der Schoot P, de Vries R, Wuite GJL, Roos WH. Real-Time Assembly of Viruslike Nucleocapsids Elucidated at the Single-Particle Level. NANO LETTERS 2019; 19:5746-5753. [PMID: 31368710 PMCID: PMC6696885 DOI: 10.1021/acs.nanolett.9b02376] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 07/24/2019] [Indexed: 05/20/2023]
Abstract
While the structure of a multitude of viral particles has been resolved to atomistic detail, their assembly pathways remain largely elusive. Key unresolved issues are particle nucleation, particle growth, and the mode of genome compaction. These issues are difficult to address in bulk approaches and are effectively only accessible by the real-time tracking of assembly dynamics of individual particles. This we do here by studying the assembly into rod-shaped viruslike particles (VLPs) of artificial capsid polypeptides. Using fluorescence optical tweezers, we establish that small oligomers perform one-dimensional diffusion along the DNA. Larger oligomers are immobile and nucleate VLP growth. A multiplexed acoustic force spectroscopy approach reveals that DNA is compacted in regular steps, suggesting packaging via helical wrapping into a nucleocapsid. By reporting how real-time assembly tracking elucidates viral nucleation and growth principles, our work opens the door to a fundamental understanding of the complex assembly pathways of both VLPs and naturally evolved viruses.
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Affiliation(s)
- Margherita Marchetti
- Department
of Physics and Astronomy and LaserLaB Amsterdam, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
- Moleculaire
Biofysica, Zernike Instituut, Rijksuniversiteit
Groningen, 9712 CP Groningen, The Netherlands
| | - Douwe Kamsma
- Department
of Physics and Astronomy and LaserLaB Amsterdam, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Ernesto Cazares Vargas
- Institute
of Chemistry, Department of Chemistry of Biomacromolecules, National Autonomous University of Mexico, 04510 Mexico City, Mexico
| | - Armando Hernandez García
- Institute
of Chemistry, Department of Chemistry of Biomacromolecules, National Autonomous University of Mexico, 04510 Mexico City, Mexico
| | - Paul van der Schoot
- Institute
for Theoretical Physics, Utrecht University, 3512 JE Utrecht, The Netherlands
- Department
of Applied Physics, Eindhoven University
of Technology, 5612 AZ Eindhoven, The Netherlands
| | - Renko de Vries
- Laboratory
of Physical Chemistry and Colloid Science, Wageningen University, 6708 PB Wageningen, The Netherlands
| | - Gijs J. L. Wuite
- Department
of Physics and Astronomy and LaserLaB Amsterdam, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
- E-mail:
| | - Wouter H. Roos
- Moleculaire
Biofysica, Zernike Instituut, Rijksuniversiteit
Groningen, 9712 CP Groningen, The Netherlands
- E-mail:
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35
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Hafner AE, Krausser J, Šarić A. Minimal coarse-grained models for molecular self-organisation in biology. Curr Opin Struct Biol 2019; 58:43-52. [PMID: 31226513 DOI: 10.1016/j.sbi.2019.05.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 05/13/2019] [Accepted: 05/19/2019] [Indexed: 01/19/2023]
Abstract
The molecular machinery of life is largely created via self-organisation of individual molecules into functional assemblies. Minimal coarse-grained models, in which a whole macromolecule is represented by a small number of particles, can be of great value in identifying the main driving forces behind self-organisation in cell biology. Such models can incorporate data from both molecular and continuum scales, and their results can be directly compared to experiments. Here we review the state of the art of models for studying the formation and biological function of macromolecular assemblies in living organisms. We outline the key ingredients of each model and their main findings. We illustrate the contribution of this class of simulations to identifying the physical mechanisms behind life and diseases, and discuss their future developments.
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Affiliation(s)
- Anne E Hafner
- Department of Physics and Astronomy, Institute for the Physics of Living Systems, University College London, London WC1E 6BT, UK
| | - Johannes Krausser
- Department of Physics and Astronomy, Institute for the Physics of Living Systems, University College London, London WC1E 6BT, UK
| | - Anđela Šarić
- Department of Physics and Astronomy, Institute for the Physics of Living Systems, University College London, London WC1E 6BT, UK.
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36
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Kopatz I, Zalk R, Levi-Kalisman Y, Zlotkin-Rivkin E, Frank GA, Kler S. Packaging of DNA origami in viral capsids. NANOSCALE 2019; 11:10160-10166. [PMID: 30994643 DOI: 10.1039/c8nr10113b] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Here we show the encapsulation of 35 nm diameter, nearly-spherical, DNA origami by self-assembly of SV40-like (simian virus 40) particles. The self-assembly of this new type of nanoparticles is highly reproducible and efficient. The structure of these particles was determined by cryo-EM. The capsid forms a regular SV40 lattice of T = 7d icosahedral symmetry and the structural features of encapsulated DNA origami are fully visible. These particles are a promising biomaterial for use in various medical applications.
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37
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Comas-Garcia M. Packaging of Genomic RNA in Positive-Sense Single-Stranded RNA Viruses: A Complex Story. Viruses 2019; 11:v11030253. [PMID: 30871184 PMCID: PMC6466141 DOI: 10.3390/v11030253] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 03/07/2019] [Accepted: 03/08/2019] [Indexed: 02/06/2023] Open
Abstract
The packaging of genomic RNA in positive-sense single-stranded RNA viruses is a key part of the viral infectious cycle, yet this step is not fully understood. Unlike double-stranded DNA and RNA viruses, this process is coupled with nucleocapsid assembly. The specificity of RNA packaging depends on multiple factors: (i) one or more packaging signals, (ii) RNA replication, (iii) translation, (iv) viral factories, and (v) the physical properties of the RNA. The relative contribution of each of these factors to packaging specificity is different for every virus. In vitro and in vivo data show that there are different packaging mechanisms that control selective packaging of the genomic RNA during nucleocapsid assembly. The goals of this article are to explain some of the key experiments that support the contribution of these factors to packaging selectivity and to draw a general scenario that could help us move towards a better understanding of this step of the viral infectious cycle.
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Affiliation(s)
- Mauricio Comas-Garcia
- Research Center for Health Sciences and Biomedicine (CICSaB), Universidad Autónoma de San Luis Potosí (UASLP), Av. Sierra Leona 550 Lomas 2da Seccion, 72810 San Luis Potosi, Mexico.
- Department of Sciences, Universidad Autónoma de San Luis Potosí (UASLP), Av. Chapultepec 1570, Privadas del Pedregal, 78295 San Luis Potosi, Mexico.
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38
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A New Model System for Exploring Assembly Mechanisms of the HIV-1 Immature Capsid In Vivo. Bull Math Biol 2019; 81:1506-1526. [PMID: 30706326 DOI: 10.1007/s11538-019-00571-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 01/23/2019] [Indexed: 10/27/2022]
Abstract
The assembly of the HIV-1 immature capsid (HIC) is an essential step in the virus life cycle. In vivo, the HIC is composed of [Formula: see text] hexameric building blocks, and it takes 5-6 min to complete the assembly process. The involvement of numerous building blocks and the rapid timecourse makes it difficult to understand the HIC assembly process. In this work, we study HIC assembly in vivo by using differential equations. We first obtain a full model with 420 differential equations. Then, we reduce six addition reactions for separate building blocks to a single complex reaction. This strategy reduces the full model to 70 equations. Subsequently, the theoretical analysis of the reduced model shows that it might not be an effective way to decrease the HIC concentration at the equilibrium state by decreasing the microscopic on-rate constants. Based on experimental data, we estimate that the nucleating structure is much smaller than the HIC. We also estimate that the microscopic on-rate constant for nucleation reactions is far less than that for elongation reactions. The parametric collinearity investigation testifies the reliability of these two characteristics, which might explain why free building blocks do not readily polymerize into higher-order polymers until their concentration reaches a threshold value. These results can provide further insight into the assembly mechanisms of the HIC in vivo.
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39
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Jefferys EE, Sansom MSP. Computational Virology: Molecular Simulations of Virus Dynamics and Interactions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1215:201-233. [DOI: 10.1007/978-3-030-14741-9_10] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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40
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Panahandeh S, Li S, Zandi R. The equilibrium structure of self-assembled protein nano-cages. NANOSCALE 2018; 10:22802-22809. [PMID: 30516220 DOI: 10.1039/c8nr07202g] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Understanding how highly symmetric, robust, monodisperse protein nano-cages self-assemble can have major applications in various areas of bio-nanotechnology, such as drug delivery, biomedical imaging and gene therapy. We develop a model to investigate the assembly of protein subunits into the structures with different sizes and symmetries. Using Monte Carlo simulation, we obtain global minimum energy structures. Our results suggest that the physical properties including the spontaneous curvature, flexibility and bending rigidity of coat proteins are sufficient to predict the size, symmetry and shape selectivity of the assembly products. Further, on a thermodynamic basis, we discuss the polymorphism of nano-cages observed in assembly experiments.
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Affiliation(s)
- Sanaz Panahandeh
- Department of Physics and Astronomy, University of California, Riverside, California 92521, USA.
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41
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Borodavka A, Desselberger U, Patton JT. Genome packaging in multi-segmented dsRNA viruses: distinct mechanisms with similar outcomes. Curr Opin Virol 2018; 33:106-112. [PMID: 30145433 PMCID: PMC6289821 DOI: 10.1016/j.coviro.2018.08.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 07/31/2018] [Accepted: 08/01/2018] [Indexed: 12/20/2022]
Abstract
Segmented double-stranded (ds)RNA viruses share remarkable similarities in their replication strategy and capsid structure. During virus replication, positive-sense single-stranded (+)RNAs are packaged into procapsids, where they serve as templates for dsRNA synthesis, forming progeny particles containing a complete equimolar set of genome segments. How the +RNAs are recognized and stoichiometrically packaged remains uncertain. Whereas bacteriophages of the Cystoviridae family rely on specific RNA-protein interactions to select appropriate +RNAs for packaging, viruses of the Reoviridae instead rely on specific inter-molecular interactions between +RNAs that guide multi-segmented genome assembly. While these families use distinct mechanisms to direct +RNA packaging, both yield progeny particles with a complete set of genomic dsRNAs.
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Affiliation(s)
- Alexander Borodavka
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Ulrich Desselberger
- Department of Medicine, Addenbrooke's Hospital, University of Cambridge, Cambridge CB2 0QQ, UK
| | - John T Patton
- Department of Biology, Indiana University, Bloomington, IN 47405, USA.
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42
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Abstract
While small single-stranded viral shells encapsidate their genome spontaneously, many large viruses, such as the herpes simplex virus or infectious bursal disease virus (IBDV), typically require a template, consisting of either scaffolding proteins or an inner core. Despite the proliferation of large viruses in nature, the mechanisms by which hundreds or thousands of proteins assemble to form structures with icosahedral order (IO) is completely unknown. Using continuum elasticity theory, we study the growth of large viral shells (capsids) and show that a nonspecific template not only selects the radius of the capsid, but also leads to the error-free assembly of protein subunits into capsids with universal IO. We prove that as a spherical cap grows, there is a deep potential well at the locations of disclinations that later in the assembly process will become the vertices of an icosahedron. Furthermore, we introduce a minimal model and simulate the assembly of a viral shell around a template under nonequilibrium conditions and find a perfect match between the results of continuum elasticity theory and the numerical simulations. Besides explaining available experimental results, we provide a number of predictions. Implications for other problems in spherical crystals are also discussed.
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43
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Chen J, Lansac Y, Tresset G. Interactions between the Molecular Components of the Cowpea Chlorotic Mottle Virus Investigated by Molecular Dynamics Simulations. J Phys Chem B 2018; 122:9490-9498. [DOI: 10.1021/acs.jpcb.8b08026] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jingzhi Chen
- Laboratoire de Physique des Solides, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - Yves Lansac
- GREMAN, UMR 7347, CNRS, Université de Tours, 37200 Tours, France
| | - Guillaume Tresset
- Laboratoire de Physique des Solides, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France
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44
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Maassen SJ, van der Schoot P, Cornelissen JJLM. Experimental and Theoretical Determination of the pH inside the Confinement of a Virus-Like Particle. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1802081. [PMID: 30102454 DOI: 10.1002/smll.201802081] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 07/17/2018] [Indexed: 06/08/2023]
Abstract
In biology, a variety of highly ordered nanometer-size protein cages is found. Such structures find increasing application in, for example, vaccination, drug delivery, and catalysis. Understanding the physiochemical properties, particularly inside the confinement of a protein cage, helps to predict the behavior and properties of new materials based on such particles. Here, the relation between the bulk solution pH and the local pH inside a model protein cage, based on virus-like particles (VLPs) built from the coat proteins of the cowpea chlorotic mottle virus, is investigated. The pH is a crucial parameter in a variety of processes and is potentially significantly influenced by the high concentration of charges residing on the interior of the VLPs. The data show a systematic more acidic pH of 0.5 unit inside the VLP compared to that of the bulk solution for pH values above pH 6, which is explained using a theoretical model based on a Donnan equilibrium. The model agrees with the experimental data over almost two orders of magnitude, while below pH 6 the experimental data point to a buffering capacity of the VLP. These results are a first step in a better understanding of the physiochemical conditions inside a protein cage.
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Affiliation(s)
- Stan J Maassen
- Laboratory of Biomolecular Nanotechnology, MESA+ Institute for Nanotechnology, University of Twente, Enschede, 7500, AE, The Netherlands
| | - Paul van der Schoot
- Group Theory of Polymers and Soft Matter, Eindhoven University of Technology, PO Box 513, 5600, MB, Eindhoven, The Netherlands
- Institute for Theoretical Physics, Utrecht University, Princetonplein 5, 3584, CC, Utrecht, The Netherlands
| | - Jeroen J L M Cornelissen
- Laboratory of Biomolecular Nanotechnology, MESA+ Institute for Nanotechnology, University of Twente, Enschede, 7500, AE, The Netherlands
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45
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Mohajerani F, Hagan MF. The role of the encapsulated cargo in microcompartment assembly. PLoS Comput Biol 2018; 14:e1006351. [PMID: 30063715 PMCID: PMC6086489 DOI: 10.1371/journal.pcbi.1006351] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 08/10/2018] [Accepted: 07/10/2018] [Indexed: 11/19/2022] Open
Abstract
Bacterial microcompartments are large, roughly icosahedral shells that assemble around enzymes and reactants involved in certain metabolic pathways in bacteria. Motivated by microcompartment assembly, we use coarse-grained computational and theoretical modeling to study the factors that control the size and morphology of a protein shell assembling around hundreds to thousands of molecules. We perform dynamical simulations of shell assembly in the presence and absence of cargo over a range of interaction strengths, subunit and cargo stoichiometries, and the shell spontaneous curvature. Depending on these parameters, we find that the presence of a cargo can either increase or decrease the size of a shell relative to its intrinsic spontaneous curvature, as seen in recent experiments. These features are controlled by a balance of kinetic and thermodynamic effects, and the shell size is assembly pathway dependent. We discuss implications of these results for synthetic biology efforts to target new enzymes to microcompartment interiors.
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Affiliation(s)
- Farzaneh Mohajerani
- Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts, United States of America
| | - Michael F. Hagan
- Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts, United States of America
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46
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Shen K, Wang ZG. Electrostatic correlations and the polyelectrolyte self energy. J Chem Phys 2018; 146:084901. [PMID: 28249457 DOI: 10.1063/1.4975777] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We address the effects of chain connectivity on electrostaticfluctuations in polyelectrolyte solutions using a field-theoretic, renormalizedGaussian fluctuation (RGF) theory. As in simple electrolyte solutions [Z.-G. Wang,Phys. Rev. E 81, 021501 (2010)], the RGF provides a unified theory forelectrostatic fluctuations, accounting for both dielectric and charge correlationeffects in terms of the self-energy. Unlike simple ions, the polyelectrolyte self energydepends intimately on the chain conformation, and our theory naturally provides aself-consistent determination of the response of intramolecular chain structure topolyelectrolyte and salt concentrations. The effects of the chain-conformation on theself-energy and thermodynamics are especially pronounced for flexiblepolyelectrolytes at low polymer and salt concentrations, where application of thewrong chain structure can lead to a drastic misestimation of the electrostaticcorrelations. By capturing the expected scaling behavior of chain size from dilute tosemi-dilute regimes, our theory provides improved estimates of the self energy at lowpolymer concentrations and correctly predicts the eventual N-independenceof the critical temperature and concentration of salt-free solutions of flexiblepolyelectrolytes. We show that the self energy can be interpreted in terms of aninfinite-dilution energy μm,0el and a finite concentrationcorrelation correction μcorr which tends to cancel out the formerwith increasing concentration.
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Affiliation(s)
- Kevin Shen
- Division of Chemistry andChemical Engineering, California Institute of TechnologyPasadena, Pasadena, California 91125,USA
| | - Zhen-Gang Wang
- Division of Chemistry andChemical Engineering, California Institute of TechnologyPasadena, Pasadena, California 91125,USA
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47
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Grosberg AY, Bruinsma R. Confining annealed branched polymers inside spherical capsids. J Biol Phys 2018; 44:133-145. [PMID: 29442192 PMCID: PMC5928018 DOI: 10.1007/s10867-018-9483-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 01/19/2018] [Indexed: 10/18/2022] Open
Abstract
The Lifshitz equation for the confinement of a linear polymer in a spherical cavity of radius R has the form of the Schrödinger equation for a quantum particle trapped in a potential well with flat bottom and infinite walls at radius R. We show that the Lifshitz equation of a confined annealed branched polymer has the form of the Schrödinger equation for a quantum harmonic oscillator. The resulting confinement energy has a 1/R4 dependence on the confinement radius R, in contrast to the case of confined linear polymers, which have a 1/R2 dependence. We discuss the application of this result to the problem of the confinement of single-stranded RNA molecules inside spherical capsids.
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Affiliation(s)
- Alexander Y Grosberg
- Department of Physics and Center for Soft Matter Research, New York University, 726 Broadway, New York, NY, 10003, USA.
| | - Robijn Bruinsma
- Department of Physics and Astronomy, University of California, Los Angeles, CA, 90095, USA
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
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48
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Li S, Orland H, Zandi R. Self consistent field theory of virus assembly. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:144002. [PMID: 29460850 PMCID: PMC7104907 DOI: 10.1088/1361-648x/aab0c6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Revised: 02/12/2018] [Accepted: 02/20/2018] [Indexed: 05/04/2023]
Abstract
The ground state dominance approximation (GSDA) has been extensively used to study the assembly of viral shells. In this work we employ the self-consistent field theory (SCFT) to investigate the adsorption of RNA onto positively charged spherical viral shells and examine the conditions when GSDA does not apply and SCFT has to be used to obtain a reliable solution. We find that there are two regimes in which GSDA does work. First, when the genomic RNA length is long enough compared to the capsid radius, and second, when the interaction between the genome and capsid is so strong that the genome is basically localized next to the wall. We find that for the case in which RNA is more or less distributed uniformly in the shell, regardless of the length of RNA, GSDA is not a good approximation. We observe that as the polymer-shell interaction becomes stronger, the energy gap between the ground state and first excited state increases and thus GSDA becomes a better approximation. We also present our results corresponding to the genome persistence length obtained through the tangent-tangent correlation length and show that it is zero in case of GSDA but is equal to the inverse of the energy gap when using SCFT.
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Affiliation(s)
- Siyu Li
- Department of Physics and Astronomy, University of California, Riverside, CA 92521, United States of America
- Institut de Physique Théorique, CEA-Saclay, CEA, F-91191 Gif-sur-Yvette, France
- Beijing Computational Science Research Center, No.10 East Xibeiwang Road, Haidan District, Beijing 100193, People’s Republic of China
| | - Henri Orland
- Institut de Physique Théorique, CEA-Saclay, CEA, F-91191 Gif-sur-Yvette, France
- Beijing Computational Science Research Center, No.10 East Xibeiwang Road, Haidan District, Beijing 100193, People’s Republic of China
| | - Roya Zandi
- Department of Physics and Astronomy, University of California, Riverside, CA 92521, United States of America
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49
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Lošdorfer Božič A, Micheletti C, Podgornik R, Tubiana L. Compactness of viral genomes: effect of disperse and localized random mutations. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:084006. [PMID: 29334364 PMCID: PMC7104904 DOI: 10.1088/1361-648x/aaa7b0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 12/29/2017] [Accepted: 01/15/2018] [Indexed: 06/07/2023]
Abstract
Genomes of single-stranded RNA viruses have evolved to optimize several concurrent properties. One of them is the architecture of their genomic folds, which must not only feature precise structural elements at specific positions, but also allow for overall spatial compactness. The latter was shown to be disrupted by random synonymous mutations, a disruption which can consequently negatively affect genome encapsidation. In this study, we use three mutation schemes with different degrees of locality to mutate the genomes of phage MS2 and Brome Mosaic virus in order to understand the observed sensitivity of the global compactness of their folds. We find that mutating local stretches of their genomes' sequence or structure is less disruptive to their compactness compared to inducing randomly-distributed mutations. Our findings are indicative of a mechanism for the conservation of compactness acting on a global scale of the genomes, and have several implications for understanding the interplay between local and global architecture of viral RNA genomes.
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Affiliation(s)
- Anže Lošdorfer Božič
- Department of Theoretical Physics, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
| | | | - Rudolf Podgornik
- Department of Theoretical Physics, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
- Department of Physics, Faculty of Mathematics and Physics, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Luca Tubiana
- Faculty of Physics, University of Vienna, A-1090 Vienna, Austria
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50
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Li S, Erdemci-Tandogan G, van der Schoot P, Zandi R. The effect of RNA stiffness on the self-assembly of virus particles. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:044002. [PMID: 29235442 PMCID: PMC7104906 DOI: 10.1088/1361-648x/aaa159] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/06/2017] [Accepted: 12/13/2017] [Indexed: 05/21/2023]
Abstract
Under many in vitro conditions, some small viruses spontaneously encapsidate a single stranded (ss) RNA into a protein shell called the capsid. While viral RNAs are found to be compact and highly branched because of long distance base-pairing between nucleotides, recent experiments reveal that in a head-to-head competition between an ssRNA with no secondary or higher order structure and a viral RNA, the capsid proteins preferentially encapsulate the linear polymer! In this paper, we study the impact of genome stiffness on the encapsidation free energy of the complex of RNA and capsid proteins. We show that an increase in effective chain stiffness because of base-pairing could be the reason why under certain conditions linear chains have an advantage over branched chains when it comes to encapsidation efficiency. While branching makes the genome more compact, RNA base-pairing increases the effective Kuhn length of the RNA molecule, which could result in an increase of the free energy of RNA confinement, that is, the work required to encapsidate RNA, and thus less efficient packaging.
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Affiliation(s)
- Siyu Li
- Department of Physics and Astronomy, University of California, Riverside, CA 92521, United States of America
| | - Gonca Erdemci-Tandogan
- Department of Physics, Syracuse University, Syracuse, NY 13244, United States of America
| | - Paul van der Schoot
- Group Theory of Polymers and Soft Matter, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, Netherlands
- Institute for Theoretical Physics, Utrecht University, Princetonplein 5, 3584 CC Utrecht, Netherlands
| | - Roya Zandi
- Department of Physics and Astronomy, University of California, Riverside, CA 92521, United States of America
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