1
|
Cingolani G, Iglesias S, Hou CF, Lemire S, Soriaga A, Kyme P. Cryo-EM analysis of Pseudomonas phage Pa193 structural components. RESEARCH SQUARE 2024:rs.3.rs-4189479. [PMID: 38659960 PMCID: PMC11042391 DOI: 10.21203/rs.3.rs-4189479/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
The World Health Organization has designated Pseudomonas aeruginosa as a critical pathogen for the development of new antimicrobials. Bacterial viruses, or bacteriophages, have been used in various clinical settings, commonly called phage therapy, to address this growing public health crisis. Here, we describe a high-resolution structural atlas of a therapeutic, contractile-tailed Pseudomonas phage, Pa193. We used bioinformatics, proteomics, and cryogenic electron microscopy single particle analysis to identify, annotate, and build atomic models for 21 distinct structural polypeptide chains forming the icosahedral capsid, neck, contractile tail, and baseplate. We identified a putative scaffolding protein stabilizing the interior of the capsid 5-fold vertex. We also visualized a large portion of Pa193 ~ 500 Å long tail fibers and resolved the interface between the baseplate and tail fibers. The work presented here provides a framework to support a better understanding of phages as biomedicines for phage therapy and inform engineering opportunities.
Collapse
|
2
|
Kim KJ, Kim G, Bae JH, Song JJ, Kim HS. A pH-Responsive Virus-Like Particle as a Protein Cage for a Targeted Delivery. Adv Healthc Mater 2024; 13:e2302656. [PMID: 37966427 DOI: 10.1002/adhm.202302656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 11/05/2023] [Indexed: 11/16/2023]
Abstract
A stimuli-responsive protein self-assembly offers promising utility as a protein nanocage for biotechnological and medical applications. Herein, the development of a virus-like particle (VLP) that undergoes a transition between assembly and disassembly under a neutral and acidic pH, respectively, for a targeted delivery is reported. The structure of the bacteriophage P22 coat protein is used for the computational design of coat subunits that self-assemble into a pH-responsive VLP. Subunit designs are generated through iterative computational cycles of histidine substitutions and evaluation of the interaction energies among the subunits under an acidic and neutral pH. The top subunit designs are tested and one that is assembled into a VLP showing the highest pH-dependent structural transition is selected. The cryo-EM structure of the VLP is determined, and the structural basis of a pH-triggered disassembly is delineated. The utility of the designed VLP is exemplified through the targeted delivery of a cytotoxic protein cargo into tumor cells in a pH-dependent manner. These results provide strategies for the development of self-assembling protein architectures with new functionality for diverse applications.
Collapse
Affiliation(s)
- Kwan-Jip Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Daejon, 34141, South Korea
| | - Gijeong Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Daejon, 34141, South Korea
| | - Jin-Ho Bae
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Daejon, 34141, South Korea
| | - Ji-Joon Song
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Daejon, 34141, South Korea
| | - Hak-Sung Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Daejon, 34141, South Korea
| |
Collapse
|
3
|
Iglesias SM, Lokareddy RK, Yang R, Li F, Yeggoni DP, David Hou CF, Leroux MN, Cortines JR, Leavitt JC, Bird M, Casjens SR, White S, Teschke CM, Cingolani G. Molecular Architecture of Salmonella Typhimurium Virus P22 Genome Ejection Machinery. J Mol Biol 2023; 435:168365. [PMID: 37952769 PMCID: PMC10842050 DOI: 10.1016/j.jmb.2023.168365] [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: 09/01/2023] [Revised: 11/04/2023] [Accepted: 11/07/2023] [Indexed: 11/14/2023]
Abstract
Bacteriophage P22 is a prototypical member of the Podoviridae superfamily. Since its discovery in 1952, P22 has become a paradigm for phage transduction and a model for icosahedral viral capsid assembly. Here, we describe the complete architecture of the P22 tail apparatus (gp1, gp4, gp10, gp9, and gp26) and the potential location and organization of P22 ejection proteins (gp7, gp20, and gp16), determined using cryo-EM localized reconstruction, genetic knockouts, and biochemical analysis. We found that the tail apparatus exists in two equivalent conformations, rotated by ∼6° relative to the capsid. Portal protomers make unique contacts with coat subunits in both conformations, explaining the 12:5 symmetry mismatch. The tail assembles around the hexameric tail hub (gp10), which folds into an interrupted β-propeller characterized by an apical insertion domain. The tail hub connects proximally to the dodecameric portal protein and head-to-tail adapter (gp4), distally to the trimeric tail needle (gp26), and laterally to six trimeric tailspikes (gp9) that attach asymmetrically to gp10 insertion domain. Cryo-EM analysis of P22 mutants lacking the ejection proteins gp7 or gp20 and biochemical analysis of purified recombinant proteins suggest that gp7 and gp20 form a molecular complex associated with the tail apparatus via the portal protein barrel. We identified a putative signal transduction pathway from the tailspike to the tail needle, mediated by three flexible loops in the tail hub, that explains how lipopolysaccharide (LPS) is sufficient to trigger the ejection of the P22 DNA in vitro.
Collapse
Affiliation(s)
- Stephano M Iglesias
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locus Street, Philadelphia, PA 19107, USA
| | - Ravi K Lokareddy
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 1825 University Blvd, Birmingham, AL 35294, USA
| | - Ruoyu Yang
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locus Street, Philadelphia, PA 19107, USA
| | - Fenglin Li
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locus Street, Philadelphia, PA 19107, USA
| | - Daniel P Yeggoni
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locus Street, Philadelphia, PA 19107, USA
| | - Chun-Feng David Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locus Street, Philadelphia, PA 19107, USA
| | - Makayla N Leroux
- Department of Molecular and Cell Biology, University of Connecticut, 91 N. Eagleville Road, Storrs, CT 06269, USA
| | - Juliana R Cortines
- Department of Molecular and Cell Biology, University of Connecticut, 91 N. Eagleville Road, Storrs, CT 06269, USA; Departamento de Virologia, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21590-902, Brazil
| | - Justin C Leavitt
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Mary Bird
- Department of Molecular and Cell Biology, University of Connecticut, 91 N. Eagleville Road, Storrs, CT 06269, USA
| | - Sherwood R Casjens
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Simon White
- Department of Molecular and Cell Biology, University of Connecticut, 91 N. Eagleville Road, Storrs, CT 06269, USA
| | - Carolyn M Teschke
- Department of Molecular and Cell Biology, University of Connecticut, 91 N. Eagleville Road, Storrs, CT 06269, USA; Department of Chemistry, University of Connecticut, 91 N. Eagleville Road, Storrs, CT 06269, USA
| | - Gino Cingolani
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locus Street, Philadelphia, PA 19107, USA; Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 1825 University Blvd, Birmingham, AL 35294, USA.
| |
Collapse
|
4
|
Wang Y, Selivanovitch E, Douglas T. Enhancing Multistep Reactions: Biomimetic Design of Substrate Channeling Using P22 Virus-Like Particles. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2206906. [PMID: 36815387 PMCID: PMC10161098 DOI: 10.1002/advs.202206906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/09/2023] [Indexed: 05/06/2023]
Abstract
Many biocatalytic processes inside cells employ substrate channeling to control the diffusion of intermediates for improved efficiency of enzymatic cascade reactions. This inspirational mechanism offers a strategy for increasing efficiency of multistep biocatalysis, especially where the intermediates are expensive cofactors that require continuous regeneration. However, it is challenging to achieve substrate channeling artificially in vitro due to fast diffusion of small molecules. By mimicking some naturally occurring metabolons, nanoreactors are developed using P22 virus-like particles (VLPs), which enhance the efficiency of nicotinamide adenine dinucleotide (NAD)-dependent multistep biocatalysis by substrate channeling. In this design, NAD-dependent enzyme partners are coencapsulated inside the VLPs, while the cofactor is covalently tethered to the capsid interior through swing arms. The crowded environment inside the VLPs induces colocalization of the enzymes and the immobilized NAD, which shuttles between the enzymes for in situ regeneration without diffusing into the bulk solution. The modularity of the nanoreactors allows to tune their composition and consequently their overall activity, and also remodel them for different reactions by altering enzyme partners. Given the plasticity and versatility, P22 VLPs possess great potential for developing functional materials capable of multistep biotransformations with advantageous properties, including enhanced efficiency and economical usage of enzyme cofactors.
Collapse
Affiliation(s)
- Yang Wang
- Department of ChemistryIndiana University800 E Kirkwood AveBloomingtonIN47405USA
| | | | - Trevor Douglas
- Department of ChemistryIndiana University800 E Kirkwood AveBloomingtonIN47405USA
| |
Collapse
|
5
|
Essus VA, Souza Júnior GSE, Nunes GHP, Oliveira JDS, de Faria BM, Romão LF, Cortines JR. Bacteriophage P22 Capsid as a Pluripotent Nanotechnology Tool. Viruses 2023; 15:516. [PMID: 36851730 PMCID: PMC9962691 DOI: 10.3390/v15020516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/09/2023] [Accepted: 02/10/2023] [Indexed: 02/15/2023] Open
Abstract
The Salmonella enterica bacteriophage P22 is one of the most promising models for the development of virus-like particle (VLP) nanocages. It possesses an icosahedral T = 7 capsid, assembled by the combination of two structural proteins: the coat protein (gp5) and the scaffold protein (gp8). The P22 capsid has the remarkable capability of undergoing structural transition into three morphologies with differing diameters and wall-pore sizes. These varied morphologies can be explored for the design of nanoplatforms, such as for the development of cargo internalization strategies. The capsid proteic nature allows for the extensive modification of its structure, enabling the addition of non-native structures to alter the VLP properties or confer them to diverse ends. Various molecules were added to the P22 VLP through genetic, chemical, and other means to both the capsid and the scaffold protein, permitting the encapsulation or the presentation of cargo. This allows the particle to be exploited for numerous purposes-for example, as a nanocarrier, nanoreactor, and vaccine model, among other applications. Therefore, the present review intends to give an overview of the literature on this amazing particle.
Collapse
Affiliation(s)
- Victor Alejandro Essus
- Laboratório de Virologia e Espectrometria de Massas (LAVEM), Departamento de Virologia, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21590-902, Brazil
| | - Getúlio Silva e Souza Júnior
- Laboratório de Virologia e Espectrometria de Massas (LAVEM), Departamento de Virologia, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21590-902, Brazil
| | - Gabriel Henrique Pereira Nunes
- Laboratório de Virologia e Espectrometria de Massas (LAVEM), Departamento de Virologia, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21590-902, Brazil
| | - Juliana dos Santos Oliveira
- Laboratório de Virologia e Espectrometria de Massas (LAVEM), Departamento de Virologia, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21590-902, Brazil
| | - Bruna Mafra de Faria
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho, 373, CCS, Bl. F026, Rio de Janeiro 21941-590, Brazil
| | - Luciana Ferreira Romão
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho, 373, CCS, Bl. F026, Rio de Janeiro 21941-590, Brazil
| | - Juliana Reis Cortines
- Laboratório de Virologia e Espectrometria de Massas (LAVEM), Departamento de Virologia, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21590-902, Brazil
| |
Collapse
|
6
|
Xiao H, Zhou J, Yang F, Liu Z, Song J, Chen W, Liu H, Cheng L. Assembly and Capsid Expansion Mechanism of Bacteriophage P22 Revealed by High-Resolution Cryo-EM Structures. Viruses 2023; 15:v15020355. [PMID: 36851569 PMCID: PMC9965877 DOI: 10.3390/v15020355] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/17/2023] [Accepted: 01/23/2023] [Indexed: 01/28/2023] Open
Abstract
The formation of many double-stranded DNA viruses, such as herpesviruses and bacteriophages, begins with the scaffolding-protein-mediated assembly of the procapsid. Subsequently, the procapsid undergoes extensive structural rearrangement and expansion to become the mature capsid. Bacteriophage P22 is an established model system used to study virus maturation. Here, we report the cryo-electron microscopy structures of procapsid, empty procapsid, empty mature capsid, and mature capsid of phage P22 at resolutions of 2.6 Å, 3.9 Å, 2.8 Å, and 3.0 Å, respectively. The structure of the procapsid allowed us to build an accurate model of the coat protein gp5 and the C-terminal region of the scaffolding protein gp8. In addition, interactions among the gp5 subunits responsible for procapsid assembly and stabilization were identified. Two C-terminal α-helices of gp8 were observed to interact with the coat protein in the procapsid. The amino acid interactions between gp5 and gp8 in the procapsid were consistent with the results of previous biochemical studies involving mutant proteins. Our structures reveal hydrogen bonds and salt bridges between the gp5 subunits in the procapsid and the conformational changes of the gp5 domains involved in the closure of the local sixfold opening and a thinner capsid shell during capsid maturation.
Collapse
Affiliation(s)
- Hao Xiao
- Institute of Interdisciplinary Studies, Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410082, China
| | - Junquan Zhou
- Institute of Interdisciplinary Studies, Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410082, China
| | - Fan Yang
- Institute of Interdisciplinary Studies, Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410082, China
| | - Zheng Liu
- Kobilka Institute of Innovative Drug Discovery, School of Medicine, Chinese University of Hong Kong, Shenzhen 518172, China
| | - Jingdong Song
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 100052, China
| | - Wenyuan Chen
- Institute of Interdisciplinary Studies, Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410082, China
- Correspondence: (W.C.); (H.L.); (L.C.)
| | - Hongrong Liu
- Institute of Interdisciplinary Studies, Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410082, China
- Correspondence: (W.C.); (H.L.); (L.C.)
| | - Lingpeng Cheng
- Institute of Interdisciplinary Studies, Key Laboratory for Matter Microstructure and Function of Hunan Province, Key Laboratory of Low-dimensional Quantum Structures and Quantum Control, Hunan Normal University, Changsha 410082, China
- Correspondence: (W.C.); (H.L.); (L.C.)
| |
Collapse
|
7
|
Strobl K, Selivanovitch E, Ibáñez-Freire P, Moreno-Madrid F, Schaap IAT, Delgado-Buscalioni R, Douglas T, de Pablo PJ. Electromechanical Photophysics of GFP Packed Inside Viral Protein Cages Probed by Force-Fluorescence Hybrid Single-Molecule Microscopy. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2200059. [PMID: 35718881 PMCID: PMC9528512 DOI: 10.1002/smll.202200059] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 04/29/2022] [Indexed: 06/15/2023]
Abstract
Packing biomolecules inside virus capsids has opened new avenues for the study of molecular function in confined environments. These systems not only mimic the highly crowded conditions in nature, but also allow their manipulation at the nanoscale for technological applications. Here, green fluorescent proteins are packed in virus-like particles derived from P22 bacteriophage procapsids. The authors explore individual virus cages to monitor their emission signal with total internal reflection fluorescence microscopy while simultaneously changing the microenvironment with the stylus of atomic force microscopy. The mechanical and electronic quenching can be decoupled by ≈10% each using insulator and conductive tips, respectively. While with conductive tips the fluorescence quenches and recovers regardless of the structural integrity of the capsid, with the insulator tips quenching only occurs if the green fluorescent proteins remain organized inside the capsid. The electronic quenching is associated with the coupling of the protein fluorescence emission with the tip surface plasmon resonance. In turn, the mechanical quenching is a consequence of the unfolding of the aggregated proteins during the mechanical disruption of the capsid.
Collapse
Affiliation(s)
- Klara Strobl
- Department of Condensed Matter Physics, Universidad Autónoma de Madrid, Madrid, 28049, Spain
| | | | - Pablo Ibáñez-Freire
- Department of Condensed Matter Physics, Universidad Autónoma de Madrid, Madrid, 28049, Spain
| | - Francisco Moreno-Madrid
- Department of Condensed Matter Physics, Universidad Autónoma de Madrid, Madrid, 28049, Spain
| | | | - Rafael Delgado-Buscalioni
- Department of Condensed Matter Physics, Universidad Autónoma de Madrid, Madrid, 28049, Spain
- Institute of Condensed Matter Physics (IFIMAC), Universidad Autónoma de Madrid, Madrid, 28049, Spain
| | - Trevor Douglas
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA
| | - Pedro J de Pablo
- Department of Condensed Matter Physics, Universidad Autónoma de Madrid, Madrid, 28049, Spain
- Institute of Condensed Matter Physics (IFIMAC), Universidad Autónoma de Madrid, Madrid, 28049, Spain
| |
Collapse
|
8
|
Wang Y, Douglas T. Bioinspired Approaches to Self-Assembly of Virus-like Particles: From Molecules to Materials. Acc Chem Res 2022; 55:1349-1359. [PMID: 35507643 DOI: 10.1021/acs.accounts.2c00056] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
ConspectusWhen viewed through the lens of materials science, nature provides a vast library of hierarchically organized structures that serve as inspiration and raw materials for new synthetic materials. The structural organization of complex bioarchitectures with advanced functions arises from the association of building blocks and is strongly supported by ubiquitous mechanisms of self-assembly, where interactions among components result in spontaneous assembly into defined structures. Viruses are exemplary, where a capsid structure, often formed from the self-assembly of many individual protein subunits, serves as a vehicle for the transport and protection of the viral genome. Higher-order assemblies of viral particles are also found in nature with unexpected collective behaviors. When the infectious aspect of viruses is removed, the self-assembly of viral particles and their potential for hierarchical assembly become an inspiration for the design and construction of a new class of functional materials at a range of different length scales.Salmonella typhimurium bacteriophage P22 is a well-studied model for understanding viral self-assembly and the construction of virus-like particle (VLP)-based materials. The formation of cage-like P22 VLP structures results from scaffold protein (SP)-directed self-assembly of coat protein (CP) subunits into icosahedral capsids with encapsulation of SP inside the capsid. Employing the CP-SP interaction during self-assembly, the encapsulation of guest protein cargos inside P22 VLPs can be achieved with control over the composition and the number of guest cargos. The morphology of cargo-loaded VLPs can be altered, along with changes in both the physical properties of the capsid and the cargo-capsid interactions, by mimicking aspects of the infectious P22 viral maturation. The structure of the capsid differentiates the inside cavity from the outside environment and serves as a protecting layer for the encapsulated cargos. Pores in the capsid shell regulate molecular exchange between inside and outside, where small molecules can traverse the capsid freely while the diffusion of larger molecules is limited by the pores. The interior cavity of the P22 capsid can be packed with hundreds of copies of cargo proteins (especially enzymes), enforcing intermolecular proximity, making this an ideal model system in which to study enzymatic catalysis in crowded and confined environments. These aspects highlight the development of functional nanomaterials from individual P22 VLPs, through biomimetic design and self-assembly, resulting in fabrication of nanoreactors with controlled catalytic behaviors.Individual P22 VLPs have been used as building blocks for the self-assembly of higher-order structures. This relies on a balance between the intrinsic interparticle repulsion and a tunable interparticle attraction. The ordering of VLPs within three-dimensional assemblies is dependent on the balance between repulsive and attractive interactions: too strong an attraction results in kinetically trapped disordered structures, while decreasing the attraction can lead to more ordered arrays. These higher-order assemblies display collective behavior of high charge density beyond those of the individual VLPs.The development of synthetic nanomaterials based on P22 VLPs demonstrates how the potential for hierarchical self-assembly can be applied to other self-assembling capsid structures across multiple length scales toward future bioinspired functional materials.
Collapse
Affiliation(s)
- Yang Wang
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Trevor Douglas
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| |
Collapse
|
9
|
Selivanovitch E, LaFrance B, Douglas T. Molecular exclusion limits for diffusion across a porous capsid. Nat Commun 2021; 12:2903. [PMID: 34006828 PMCID: PMC8131759 DOI: 10.1038/s41467-021-23200-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 04/01/2021] [Indexed: 12/19/2022] Open
Abstract
Molecular communication across physical barriers requires pores to connect the environments on either side and discriminate between the diffusants. Here we use porous virus-like particles (VLPs) derived from bacteriophage P22 to investigate the range of molecule sizes able to gain access to its interior. Although there are cryo-EM models of the VLP, they may not accurately depict the parameters of the molecules able to pass across the pores due to the dynamic nature of the P22 particles in the solution. After encapsulating the enzyme AdhD within the P22 VLPs, we use a redox reaction involving PAMAM dendrimer modified NADH/NAD+ to examine the size and charge limitations of molecules entering P22. Utilizing the three different accessible morphologies of the P22 particles, we determine the effective pore sizes of each and demonstrate that negatively charged substrates diffuse across more readily when compared to those that are neutral, despite the negatively charge exterior of the particles.
Collapse
Affiliation(s)
| | - Benjamin LaFrance
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA, USA
| | - Trevor Douglas
- Department of Chemistry, Indiana University, Bloomington, IN, USA.
| |
Collapse
|
10
|
Ignatiou A, Brasilès S, El Sadek Fadel M, Bürger J, Mielke T, Topf M, Tavares P, Orlova EV. Structural transitions during the scaffolding-driven assembly of a viral capsid. Nat Commun 2019; 10:4840. [PMID: 31649265 PMCID: PMC6813328 DOI: 10.1038/s41467-019-12790-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 09/25/2019] [Indexed: 11/11/2022] Open
Abstract
Assembly of tailed bacteriophages and herpesviruses starts with formation of procapsids (virion precursors without DNA). Scaffolding proteins (SP) drive assembly by chaperoning the major capsid protein (MCP) to build an icosahedral lattice. Here we report near-atomic resolution cryo-EM structures of the bacteriophage SPP1 procapsid, the intermediate expanded procapsid with partially released SPs, and the mature capsid with DNA. In the intermediate state, SPs are bound only to MCP pentons and to adjacent subunits from hexons. SP departure results in the expanded state associated with unfolding of the MCP N-terminus and straightening of E-loops. The newly formed extensive inter-capsomere bonding appears to compensate for release of SPs that clasp MCP capsomeres together. Subsequent DNA packaging instigates bending of MCP A domain loops outwards, closing the hexons central opening and creating the capsid auxiliary protein binding interface. These findings provide a molecular basis for the sequential structural rearrangements during viral capsid maturation.
Collapse
Affiliation(s)
- Athanasios Ignatiou
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London, WC1E 7HX, UK
| | - Sandrine Brasilès
- Department of Virology, Institut de Biologie Intégrative de la Cellule (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette, France
| | - Mehdi El Sadek Fadel
- Department of Virology, Institut de Biologie Intégrative de la Cellule (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette, France
| | - Jörg Bürger
- Max-Planck-Institut für Molekulare Genetik, Microscopy and Cryo-Electron Microscopy Group, Ihnestraße 63-73, 14195, Berlin, Germany
- Medizinische Physik und Biophysik, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Thorsten Mielke
- Max-Planck-Institut für Molekulare Genetik, Microscopy and Cryo-Electron Microscopy Group, Ihnestraße 63-73, 14195, Berlin, Germany
| | - Maya Topf
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London, WC1E 7HX, UK
| | - Paulo Tavares
- Department of Virology, Institut de Biologie Intégrative de la Cellule (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette, France.
| | - Elena V Orlova
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, London, WC1E 7HX, UK.
| |
Collapse
|
11
|
Whitehead RD, Teschke CM, Alexandrescu AT. NMR Mapping of Disordered Segments from a Viral Scaffolding Protein Enclosed in a 23 MDa Procapsid. Biophys J 2019; 117:1387-1392. [PMID: 31585705 DOI: 10.1016/j.bpj.2019.08.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 08/27/2019] [Accepted: 08/30/2019] [Indexed: 01/10/2023] Open
Abstract
Scaffolding proteins (SPs) are required for the capsid shell assembly of many tailed double-stranded DNA bacteriophages, some archaeal viruses, herpesviruses, and adenoviruses. Despite their importance, only one high-resolution structure is available for SPs within procapsids. Here, we use the inherent size limit of NMR to identify mobile segments of the 303-residue phage P22 SP free in solution and when incorporated into a ∼23 MDa procapsid complex. Free SP gives NMR signals from its acidic N-terminus (residues 1-40) and basic C-terminus (residues 264-303), whereas NMR signals from the middle segment (residues 41-263) are missing because of intermediate conformational exchange on the NMR chemical shift timescale. When SP is incorporated into P22 procapsids, NMR signals from the C-terminal helix-turn-helix domain disappear because of binding to the procapsid interior. Signals from the N-terminal domain persist, indicating that this segment retains flexibility when bound to procapsids. The unstructured character of the N-terminus, coupled with its high content of negative charges, is likely important for dissociation and release of SP during the double-stranded DNA genome packaging step accompanying phage maturation.
Collapse
Affiliation(s)
- Richard D Whitehead
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut
| | - Carolyn M Teschke
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut; Department of Chemistry, University of Connecticut, Storrs, Connecticut.
| | - Andrei T Alexandrescu
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut.
| |
Collapse
|
12
|
Asija K, Teschke CM. Of capsid structure and stability: The partnership between charged residues of E-loop and P-domain of the bacteriophage P22 coat protein. Virology 2019; 534:45-53. [PMID: 31176063 PMCID: PMC6614003 DOI: 10.1016/j.virol.2019.05.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 05/27/2019] [Accepted: 05/31/2019] [Indexed: 01/14/2023]
Abstract
Tailed dsDNA bacteriophages and herpesviruses form capsids using coat proteins that have the HK97 fold. In these viruses, the coat proteins first assemble into procapsids, which subsequently mature during DNA packaging. Generally interactions between the coat protein E-loop of one subunit and the P-domain of an adjacent subunit help stabilize both capsomers and capsids. Based on a recent 3.3 Å cryo-EM structure of the bacteriophage P22 virion, E-loop amino acids E52, E59 and E72 were suggested to stabilize the capsid through intra-capsomer salt bridges with the P-domain residues R102, R109 and K118. The glutamic acid residues were each mutated to alanine to test this hypothesis. The substitutions resulted in a WT phenotype and did not destabilize capsids; rather, the alanine substituted coat proteins increased the stability of procapsids and virions. These results indicate that different types of interactions must be used between the E-loop and P-domain to stabilize phage P22 procapsids and virions.
Collapse
Affiliation(s)
- Kunica Asija
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA
| | - Carolyn M Teschke
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, USA; Department of Chemistry, University of Connecticut, Storrs, CT, USA.
| |
Collapse
|
13
|
Selivanovitch E, Koliyatt R, Douglas T. Chemically Induced Morphogenesis of P22 Virus-like Particles by the Surfactant Sodium Dodecyl Sulfate. Biomacromolecules 2018; 20:389-400. [PMID: 30462501 DOI: 10.1021/acs.biomac.8b01357] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In the infectious P22 bacteriophage, the packaging of DNA into the initially formed procapsid triggers a remarkable morphological transformation where the capsid expands from 58 to 62 nm. Along with the increase in size, this maturation also provides greater stability to the capsid and initiates the release of the scaffolding protein (SP). (2,4) In the P22 virus-like particle (VLP), this transformation can be mimicked in vitro by heating the procapsid particles to 65 °C or by treatment with sodium dodecyl sulfate (SDS). (5,6) Heating the P22 particles at 65 °C for 20 min is well established to trigger the transformation of P22 to the expanded (EX) P22 VLP but does not always result in a fully expanded population. Incubation with SDS resulted in a >80% expanded population for all P22 variants used in this work. This study elucidates the importance of the stoichiometric ratio between P22 subunits and SDS, the charge of the headgroup, and length of the carbon chain for the transformation. We propose a mechanism by which the expansion takes place, where both the negatively charged sulfate group and hydrophobic tail interact with the coat protein (CP) monomers within the capsid shell in a process that is facilitated by an internal osmotic pressure generated by an encapsulated macromolecular cargo.
Collapse
Affiliation(s)
| | - Ranjit Koliyatt
- Department of Chemistry , Indiana University , Bloomington , Indiana 47405 , United States
| | - Trevor Douglas
- Department of Chemistry , Indiana University , Bloomington , Indiana 47405 , United States
| |
Collapse
|
14
|
McCoy K, Selivanovitch E, Luque D, Lee B, Edwards E, Castón JR, Douglas T. Cargo Retention inside P22 Virus-Like Particles. Biomacromolecules 2018; 19:3738-3746. [PMID: 30092631 DOI: 10.1021/acs.biomac.8b00867] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Viral protein cages, with their regular and programmable architectures, are excellent platforms for the development of functional nanomaterials. The ability to transform a virus into a material with intended structure and function relies on the existence of a well-understood model system, a noninfectious virus-like particle (VLP) counterpart. Here, we study the factors important to the ability of P22 VLP to retain or release various protein cargo molecules depending on the nature of the cargo, the capsid morphology, and the environmental conditions. Because the interaction between the internalized scaffold protein (SP) and the capsid coat protein (CP) is noncovalent, we have studied the efficiency with which a range of SP variants can dissociate from the interior of different P22 VLP morphologies and exit by traversing the porous capsid. Understanding the types of cargos that are either retained or released from the P22 VLP will aid in the rational design of functional nanomaterials.
Collapse
Affiliation(s)
- Kimberly McCoy
- Department of Chemistry , Indiana University , 800 East Kirkwood Avenue , Bloomington , Indiana 47405 , United States
| | - Ekaterina Selivanovitch
- Department of Chemistry , Indiana University , 800 East Kirkwood Avenue , Bloomington , Indiana 47405 , United States
| | - Daniel Luque
- Department of Structure of Macromolecules , Centro Nacional de Biotecnología (CNB-CSIC) , Darwin 3 , 28049 Madrid , Spain.,Centro Nacional de Microbiología/ISCIII, 28220 Majadahonda, Madrid , Spain
| | - Byeongdu Lee
- X-ray Science Division, Advanced Photon Source , Argonne National Laboratory , 9700 South Cass Avenue , Argonne , Illinois 60439 , United States
| | - Ethan Edwards
- Department of Chemistry , Indiana University , 800 East Kirkwood Avenue , Bloomington , Indiana 47405 , United States
| | - José R Castón
- Department of Structure of Macromolecules , Centro Nacional de Biotecnología (CNB-CSIC) , Darwin 3 , 28049 Madrid , Spain
| | - Trevor Douglas
- Department of Chemistry , Indiana University , 800 East Kirkwood Avenue , Bloomington , Indiana 47405 , United States
| |
Collapse
|
15
|
Abstract
Within the materials science community, proteins with cage-like architectures are being developed as versatile nanoscale platforms for use in protein nanotechnology. Much effort has been focused on the functionalization of protein cages with biological and non-biological moieties to bring about new properties of not only individual protein cages, but collective bulk-scale assemblies of protein cages. In this review, we report on the current understanding of protein cage assembly, both of the cages themselves from individual subunits, and the assembly of the individual protein cages into higher order structures. We start by discussing the key properties of natural protein cages (for example: size, shape and structure) followed by a review of some of the mechanisms of protein cage assembly and the factors that influence it. We then explore the current approaches for functionalizing protein cages, on the interior or exterior surfaces of the capsids. Lastly, we explore the emerging area of higher order assemblies created from individual protein cages and their potential for new and exciting collective properties.
Collapse
Affiliation(s)
- William M Aumiller
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA.
| | | | | |
Collapse
|
16
|
Dearborn AD, Wall EA, Kizziah JL, Klenow L, Parker LK, Manning KA, Spilman MS, Spear JM, Christie GE, Dokland T. Competing scaffolding proteins determine capsid size during mobilization of Staphylococcus aureus pathogenicity islands. eLife 2017; 6:30822. [PMID: 28984245 PMCID: PMC5644958 DOI: 10.7554/elife.30822] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 10/02/2017] [Indexed: 01/03/2023] Open
Abstract
Staphylococcus aureus pathogenicity islands (SaPIs), such as SaPI1, exploit specific helper bacteriophages, like 80α, for their high frequency mobilization, a process termed 'molecular piracy'. SaPI1 redirects the helper's assembly pathway to form small capsids that can only accommodate the smaller SaPI1 genome, but not a complete phage genome. SaPI1 encodes two proteins, CpmA and CpmB, that are responsible for this size redirection. We have determined the structures of the 80α and SaPI1 procapsids to near-atomic resolution by cryo-electron microscopy, and show that CpmB competes with the 80α scaffolding protein (SP) for a binding site on the capsid protein (CP), and works by altering the angle between capsomers. We probed these interactions genetically and identified second-site suppressors of lethal mutations in SP. Our structures show, for the first time, the detailed interactions between SP and CP in a bacteriophage, providing unique insights into macromolecular assembly processes.
Collapse
Affiliation(s)
- Altaira D Dearborn
- Protein Expression Laboratory, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, United States
| | - Erin A Wall
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, United States
| | - James L Kizziah
- Department of Microbiology, University of Alabama, Birmingham, United States
| | - Laura Klenow
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, United States
| | - Laura K Parker
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, United States.,Department of Microbiology, University of Alabama, Birmingham, United States
| | - Keith A Manning
- Department of Microbiology, University of Alabama, Birmingham, United States
| | | | - John M Spear
- Biological Science Imaging Resource, Florida State University, Tallahassee, United States
| | - Gail E Christie
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, United States
| | - Terje Dokland
- Department of Microbiology, University of Alabama, Birmingham, United States
| |
Collapse
|
17
|
Portal protein functions akin to a DNA-sensor that couples genome-packaging to icosahedral capsid maturation. Nat Commun 2017; 8:14310. [PMID: 28134243 PMCID: PMC5290284 DOI: 10.1038/ncomms14310] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 12/14/2016] [Indexed: 11/24/2022] Open
Abstract
Tailed bacteriophages and herpesviruses assemble infectious particles via an empty precursor capsid (or ‘procapsid') built by multiple copies of coat and scaffolding protein and by one dodecameric portal protein. Genome packaging triggers rearrangement of the coat protein and release of scaffolding protein, resulting in dramatic procapsid lattice expansion. Here, we provide structural evidence that the portal protein of the bacteriophage P22 exists in two distinct dodecameric conformations: an asymmetric assembly in the procapsid (PC-portal) that is competent for high affinity binding to the large terminase packaging protein, and a symmetric ring in the mature virion (MV-portal) that has negligible affinity for the packaging motor. Modelling studies indicate the structure of PC-portal is incompatible with DNA coaxially spooled around the portal vertex, suggesting that newly packaged DNA triggers the switch from PC- to MV-conformation. Thus, we propose the signal for termination of ‘Headful Packaging' is a DNA-dependent symmetrization of portal protein. Tailed bacteriophages assemble empty precursor capsids known as procapsids that are subsequently filled with viral DNA by a genome-packaging motor. Here the authors present a structure-based analysis that suggests the signal for termination of genome packaging is achieved through a DNA-dependent symmetrization of portal protein.
Collapse
|
18
|
ϕX174 Procapsid Assembly: Effects of an Inhibitory External Scaffolding Protein and Resistant Coat Proteins In Vitro. J Virol 2017; 91:JVI.01878-16. [PMID: 27795440 DOI: 10.1128/jvi.01878-16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 10/18/2016] [Indexed: 11/20/2022] Open
Abstract
During ϕX174 morphogenesis, 240 copies of the external scaffolding protein D organize 12 pentameric assembly intermediates into procapsids, a reaction reconstituted in vitro In previous studies, ϕX174 strains resistant to exogenously expressed dominant lethal D genes were experimentally evolved. Resistance was achieved by the stepwise acquisition of coat protein mutations. Once resistance was established, a stimulatory D protein mutation that greatly increased strain fitness arose. In this study, in vitro biophysical and biochemical methods were utilized to elucidate the mechanistic details and evolutionary trade-offs created by the resistance mutations. The kinetics of procapsid formation was analyzed in vitro using wild-type, inhibitory, and experimentally evolved coat and scaffolding proteins. Our data suggest that viral fitness is correlated with in vitro assembly kinetics and demonstrate that in vivo experimental evolution can be analyzed within an in vitro biophysical context. IMPORTANCE Experimental evolution is an extremely valuable tool. Comparisons between ancestral and evolved genotypes suggest hypotheses regarding adaptive mechanisms. However, it is not always possible to rigorously test these hypotheses in vivo We applied in vitro biophysical and biochemical methods to elucidate the mechanistic details that allowed an experimentally evolved virus to become resistant to an antiviral protein and then evolve a productive use for that protein. Moreover, our results indicate that the respective roles of scaffolding and coat proteins may have been redistributed during the evolution of a two-scaffolding-protein system. In one-scaffolding-protein virus assembly systems, coat proteins promiscuously interact to form heterogeneous aberrant structures in the absence of scaffolding proteins. Thus, the scaffolding protein controls fidelity. During ϕX174 assembly, the external scaffolding protein acts like a coat protein, self-associating into large aberrant spherical structures in the absence of coat protein, whereas the coat protein appears to control fidelity.
Collapse
|
19
|
Keifer DZ, Motwani T, Teschke CM, Jarrold MF. Measurement of the accurate mass of a 50 MDa infectious virus. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2016; 30:1957-62. [PMID: 27501430 PMCID: PMC5137368 DOI: 10.1002/rcm.7673] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 06/17/2016] [Accepted: 06/22/2016] [Indexed: 06/06/2023]
Abstract
RATIONALE Bacteriophage P22 is believed to contain a total of 521 copies of 9 different proteins and a 41,724 base pair genome. Despite its enormous size and complexity, phage P22 can be electrosprayed, and it remains intact in ultra-high vacuum where its molar mass distribution has been measured. METHODS Phage P22 virions were generated by complementation in Salmonella enterica and purified. They were transferred into 100 mM ammonium acetate and then electrosprayed. The masses of individual virions were determined using charge detection mass spectrometry. RESULTS The stoichiometry of the protein components of phage P22 is sufficiently well known that the theoretical molar mass can be determined to within a narrow range. The measured average molar mass of phage P22, 52,180 ± 59 kDa, is consistent with the theoretical molar mass and supports the proposed stoichiometry of the components. The intrinsic width of the phage P22 mass distribution can be accounted for by the distribution of DNA packaged by the headful mechanism. CONCLUSIONS At over 50 MDa, phage P22 is the largest object with a well-defined molar mass to be analyzed by mass spectrometry. The narrow measured mass distribution indicates that the virions survive the transition into the gas phase intact. Copyright © 2016 John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- David Z Keifer
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA
| | - Tina Motwani
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, 06269, USA
| | - Carolyn M Teschke
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, 06269, USA
- Department of Chemistry, University of Connecticut, Storrs, CT, 06269, USA
| | - Martin F Jarrold
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA
| |
Collapse
|
20
|
Wagner J, Zandi R. The Robust Assembly of Small Symmetric Nanoshells. Biophys J 2016; 109:956-65. [PMID: 26331253 DOI: 10.1016/j.bpj.2015.07.041] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 06/18/2015] [Accepted: 07/28/2015] [Indexed: 12/20/2022] Open
Abstract
Highly symmetric nanoshells are found in many biological systems, such as clathrin cages and viral shells. Many studies have shown that symmetric shells appear in nature as a result of the free-energy minimization of a generic interaction between their constituent subunits. We examine the physical basis for the formation of symmetric shells, and by using a minimal model, demonstrate that these structures can readily grow from the irreversible addition of identical subunits. Our model of nanoshell assembly shows that the spontaneous curvature regulates the size of the shell while the mechanical properties of the subunit determine the symmetry of the assembled structure. Understanding the minimum requirements for the formation of closed nanoshells is a necessary step toward engineering of nanocontainers, which will have far-reaching impact in both material science and medicine.
Collapse
Affiliation(s)
- Jef Wagner
- Department of Physics and Astronomy, University of California at Riverside, Riverside, California.
| | - Roya Zandi
- Department of Physics and Astronomy, University of California at Riverside, Riverside, California
| |
Collapse
|
21
|
Harprecht C, Okifo O, Robbins KJ, Motwani T, Alexandrescu AT, Teschke CM. Contextual Role of a Salt Bridge in the Phage P22 Coat Protein I-Domain. J Biol Chem 2016; 291:11359-72. [PMID: 27006399 DOI: 10.1074/jbc.m116.716910] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Indexed: 12/30/2022] Open
Abstract
The I-domain is a genetic insertion in the phage P22 coat protein that chaperones its folding and stability. Of 11 acidic residues in the I-domain, seven participate in stabilizing electrostatic interactions with basic residues across elements of secondary structure, fastening the β-barrel fold. A hydrogen-bonded salt bridge between Asp-302 and His-305 is particularly interesting as Asp-302 is the site of a temperature-sensitive-folding mutation. The pKa of His-305 is raised to 9.0, indicating the salt bridge stabilizes the I-domain by ∼4 kcal/mol. Consistently, urea denaturation experiments indicate the stability of the WT I-domain decreases by 4 kcal/mol between neutral and basic pH. The mutants D302A and H305A remove the pH dependence of stability. The D302A substitution destabilizes the I-domain by 4 kcal/mol, whereas H305A had smaller effects, on the order of 1-2 kcal/mol. The destabilizing effects of D302A are perpetuated in the full-length coat protein as shown by a higher sensitivity to protease digestion, decreased procapsid assembly rates, and impaired phage production in vivo By contrast, the mutants have only minor effects on capsid expansion or stability in vitro The effects of the Asp-302-His-305 salt bridge are thus complex and context-dependent. Substitutions that abolish the salt bridge destabilize coat protein monomers and impair capsid self-assembly, but once capsids are formed the effects of the substitutions are overcome by new quaternary interactions between subunits.
Collapse
Affiliation(s)
- Christina Harprecht
- From the Department of Molecular and Cell Biology and Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269
| | - Oghenefejiro Okifo
- From the Department of Molecular and Cell Biology and Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269
| | - Kevin J Robbins
- From the Department of Molecular and Cell Biology and Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269
| | - Tina Motwani
- From the Department of Molecular and Cell Biology and Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269
| | - Andrei T Alexandrescu
- From the Department of Molecular and Cell Biology and Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269
| | - Carolyn M Teschke
- From the Department of Molecular and Cell Biology and Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269
| |
Collapse
|
22
|
A Molecular Staple: D-Loops in the I Domain of Bacteriophage P22 Coat Protein Make Important Intercapsomer Contacts Required for Procapsid Assembly. J Virol 2015; 89:10569-79. [PMID: 26269173 DOI: 10.1128/jvi.01629-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 08/08/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Bacteriophage P22, a double-stranded DNA (dsDNA) virus, has a nonconserved 124-amino-acid accessory domain inserted into its coat protein, which has the canonical HK97 protein fold. This I domain is involved in virus capsid size determination and stability, as well as protein folding. The nuclear magnetic resonance (NMR) solution structure of the I domain revealed the presence of a D-loop, which was hypothesized to make important intersubunit contacts between coat proteins in adjacent capsomers. Here we show that amino acid substitutions of residues near the tip of the D-loop result in aberrant assembly products, including tubes and broken particles, highlighting the significance of the D-loops in proper procapsid assembly. Using disulfide cross-linking, we showed that the tips of the D-loops are positioned directly across from each other both in the procapsid and the mature virion, suggesting their importance in both states. Our results indicate that D-loop interactions act as "molecular staples" at the icosahedral 2-fold symmetry axis and significantly contribute to stabilizing the P22 capsid for DNA packaging. IMPORTANCE Many dsDNA viruses have morphogenic pathways utilizing an intermediate capsid, known as a procapsid. These procapsids are assembled from a coat protein having the HK97 fold in a reaction driven by scaffolding proteins or delta domains. Maturation of the capsid occurs during DNA packaging. Bacteriophage HK97 uniquely stabilizes its capsid during maturation by intercapsomer cross-linking, but most virus capsids are stabilized by alternate means. Here we show that the I domain that is inserted into the coat protein of bacteriophage P22 is important in the process of proper procapsid assembly. Specifically, the I domain allows for stabilizing interactions across the capsid 2-fold axis of symmetry via a D-loop. When amino acid residues at the tip of the D-loop are mutated, aberrant assembly products, including tubes, are formed instead of procapsids, consequently phage production is affected, indicating the importance of stabilizing interactions during the assembly and maturation reactions.
Collapse
|
23
|
Suhanovsky MM, Teschke CM. Nature's favorite building block: Deciphering folding and capsid assembly of proteins with the HK97-fold. Virology 2015; 479-480:487-97. [PMID: 25864106 PMCID: PMC4424165 DOI: 10.1016/j.virol.2015.02.055] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 02/24/2015] [Accepted: 02/27/2015] [Indexed: 01/08/2023]
Abstract
For many (if not all) bacterial and archaeal tailed viruses and eukaryotic Herpesvirdae the HK97-fold serves as the major architectural element in icosahedral capsid formation while still enabling the conformational flexibility required during assembly and maturation. Auxiliary proteins or Δ-domains strictly control assembly of multiple, identical, HK97-like subunits into procapsids with specific icosahedral symmetries, rather than aberrant non-icosahedral structures. Procapsids are precursor structures that mature into capsids in a process involving release of auxiliary proteins (or cleavage of Δ-domains), dsDNA packaging, and conformational rearrangement of the HK97-like subunits. Some coat proteins built on the ubiquitous HK97-fold also have accessory domains or loops that impart specific functions, such as increased monomer, procapsid, or capsid stability. In this review, we analyze the numerous HK97-like coat protein structures that are emerging in the literature (over 40 at time of writing) by comparing their topology, additional domains, and their assembly and misassembly reactions.
Collapse
Affiliation(s)
- Margaret M Suhanovsky
- Department of Molecular and Cell Biology, University of Connecticut, 91N. Eagleville Rd. Storrs, CT 06269-3125, USA.
| | - Carolyn M Teschke
- Department of Molecular and Cell Biology, University of Connecticut, 91N. Eagleville Rd. Storrs, CT 06269-3125, USA; Department of Chemistry, University of Connecticut, 91N. Eagleville Rd. Storrs, CT 06269-3125, USA.
| |
Collapse
|
24
|
Jiang J, Yang J, Sereda YV, Ortoleva PJ. Early stage P22 viral capsid self-assembly mediated by scaffolding protein: atom-resolved model and molecular dynamics simulation. J Phys Chem B 2015; 119:5156-62. [PMID: 25815608 DOI: 10.1021/acs.jpcb.5b00303] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Molecular dynamics simulation of an atom-resolved bacteriophage P22 capsid model is used to delineate the underlying mechanism of early stage P22 self-assembly. A dimer formed by the C-terminal fragment of scaffolding protein with a new conformation is demonstrated to catalyze capsomer (hexamer and pentamer) aggregation efficiently. Effects of scaffolding protein/coat protein binding patterns and scaffolding protein concentration on efficiency, fidelity, and capsid curvature of P22 self-assembly are identified.
Collapse
Affiliation(s)
- Jiajian Jiang
- Center for Theoretical and Computational Nanoscience, Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Jing Yang
- Center for Theoretical and Computational Nanoscience, Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Yuriy V Sereda
- Center for Theoretical and Computational Nanoscience, Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Peter J Ortoleva
- Center for Theoretical and Computational Nanoscience, Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| |
Collapse
|