1
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Streit JO, Bukvin IV, Chan SHS, Bashir S, Woodburn LF, Włodarski T, Figueiredo AM, Jurkeviciute G, Sidhu HK, Hornby CR, Waudby CA, Cabrita LD, Cassaignau AME, Christodoulou J. The ribosome lowers the entropic penalty of protein folding. Nature 2024:10.1038/s41586-024-07784-4. [PMID: 39112704 DOI: 10.1038/s41586-024-07784-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 07/04/2024] [Indexed: 08/17/2024]
Abstract
Most proteins fold during biosynthesis on the ribosome1, and co-translational folding energetics, pathways and outcomes of many proteins have been found to differ considerably from those in refolding studies2-10. The origin of this folding modulation by the ribosome has remained unknown. Here we have determined atomistic structures of the unfolded state of a model protein on and off the ribosome, which reveal that the ribosome structurally expands the unfolded nascent chain and increases its solvation, resulting in its entropic destabilization relative to the peptide chain in isolation. Quantitative 19F NMR experiments confirm that this destabilization reduces the entropic penalty of folding by up to 30 kcal mol-1 and promotes formation of partially folded intermediates on the ribosome, an observation that extends to other protein domains and is obligate for some proteins to acquire their active conformation. The thermodynamic effects also contribute to the ribosome protecting the nascent chain from mutation-induced unfolding, which suggests a crucial role of the ribosome in supporting protein evolution. By correlating nascent chain structure and dynamics to their folding energetics and post-translational outcomes, our findings establish the physical basis of the distinct thermodynamics of co-translational protein folding.
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Affiliation(s)
- Julian O Streit
- Institute of Structural and Molecular Biology, Department of Structural and Molecular Biology, University College London, London, UK
| | - Ivana V Bukvin
- Institute of Structural and Molecular Biology, Department of Structural and Molecular Biology, University College London, London, UK
| | - Sammy H S Chan
- Institute of Structural and Molecular Biology, Department of Structural and Molecular Biology, University College London, London, UK.
| | - Shahzad Bashir
- Institute of Structural and Molecular Biology, Department of Structural and Molecular Biology, University College London, London, UK
| | - Lauren F Woodburn
- Institute of Structural and Molecular Biology, Department of Structural and Molecular Biology, University College London, London, UK
| | - Tomasz Włodarski
- Institute of Structural and Molecular Biology, Department of Structural and Molecular Biology, University College London, London, UK
| | - Angelo Miguel Figueiredo
- Institute of Structural and Molecular Biology, Department of Structural and Molecular Biology, University College London, London, UK
| | - Gabija Jurkeviciute
- Institute of Structural and Molecular Biology, Department of Structural and Molecular Biology, University College London, London, UK
| | - Haneesh K Sidhu
- Institute of Structural and Molecular Biology, Department of Structural and Molecular Biology, University College London, London, UK
| | - Charity R Hornby
- Institute of Structural and Molecular Biology, Department of Structural and Molecular Biology, University College London, London, UK
| | - Christopher A Waudby
- Institute of Structural and Molecular Biology, Department of Structural and Molecular Biology, University College London, London, UK
| | - Lisa D Cabrita
- Institute of Structural and Molecular Biology, Department of Structural and Molecular Biology, University College London, London, UK
| | - Anaïs M E Cassaignau
- Institute of Structural and Molecular Biology, Department of Structural and Molecular Biology, University College London, London, UK.
| | - John Christodoulou
- Institute of Structural and Molecular Biology, Department of Structural and Molecular Biology, University College London, London, UK.
- Department of Biological Sciences, Birkbeck College, London, UK.
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2
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Włodarski T, Streit JO, Mitropoulou A, Cabrita LD, Vendruscolo M, Christodoulou J. Bayesian reweighting of biomolecular structural ensembles using heterogeneous cryo-EM maps with the cryoENsemble method. Sci Rep 2024; 14:18149. [PMID: 39103467 PMCID: PMC11300795 DOI: 10.1038/s41598-024-68468-7] [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: 02/21/2024] [Accepted: 07/24/2024] [Indexed: 08/07/2024] Open
Abstract
Cryogenic electron microscopy (cryo-EM) has emerged as a powerful method for the determination of structures of complex biological molecules. The accurate characterisation of the dynamics of such systems, however, remains a challenge. To address this problem, we introduce cryoENsemble, a method that applies Bayesian reweighting to conformational ensembles derived from molecular dynamics simulations to improve their agreement with cryo-EM data, thus enabling the extraction of dynamics information. We illustrate the use of cryoENsemble to determine the dynamics of the ribosome-bound state of the co-translational chaperone trigger factor (TF). We also show that cryoENsemble can assist with the interpretation of low-resolution, noisy or unaccounted regions of cryo-EM maps. Notably, we are able to link an unaccounted part of the cryo-EM map to the presence of another protein (methionine aminopeptidase, or MetAP), rather than to the dynamics of TF, and model its TF-bound state. Based on these results, we anticipate that cryoENsemble will find use for challenging heterogeneous cryo-EM maps for biomolecular systems encompassing dynamic components.
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Affiliation(s)
- Tomasz Włodarski
- Institute of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT, UK.
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, 02-106, Warsaw, Poland.
| | - Julian O Streit
- Institute of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Alkistis Mitropoulou
- Institute of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Lisa D Cabrita
- Institute of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Michele Vendruscolo
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - John Christodoulou
- Institute of Structural and Molecular Biology, University College London, Gower Street, London, WC1E 6BT, UK
- Birkbeck College, University of London, Malet Street, London, WC1E 7HX, UK
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3
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Herling TW, Cassaignau AME, Wentink AS, Peter QAE, Kumar PC, Kartanas T, Schneider MM, Cabrita LD, Christodoulou J, Knowles TPJ. Thermodynamic profiles for cotranslational trigger factor substrate recognition. SCIENCE ADVANCES 2024; 10:eadn4824. [PMID: 38985872 PMCID: PMC11235164 DOI: 10.1126/sciadv.adn4824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 06/04/2024] [Indexed: 07/12/2024]
Abstract
Molecular chaperones are central to the maintenance of proteostasis in living cells. A key member of this protein family is trigger factor (TF), which acts throughout the protein life cycle and has a ubiquitous role as the first chaperone encountered by proteins during synthesis. However, our understanding of how TF achieves favorable interactions with such a diverse substrate base remains limited. Here, we use microfluidics to reveal the thermodynamic determinants of this process. We find that TF binding to empty 70S ribosomes is enthalpy-driven, with micromolar affinity, while nanomolar affinity is achieved through a favorable entropic contribution for both intrinsically disordered and folding-competent nascent chains. These findings suggest a general mechanism for cotranslational TF function, which relies on occupation of the exposed TF-substrate binding groove rather than specific complementarity between chaperone and nascent chain. These insights add to our wider understanding of how proteins can achieve broad substrate specificity.
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Affiliation(s)
- Therese W. Herling
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
| | - Anaïs M. E. Cassaignau
- Institute of Structural and Molecular Biology, University College London and Birkbeck College, London WC1 6BT, UK
| | - Anne S. Wentink
- Institute of Structural and Molecular Biology, University College London and Birkbeck College, London WC1 6BT, UK
| | - Quentin A. E. Peter
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
| | - Pavan C. Kumar
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
| | - Tadas Kartanas
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
| | - Matthias M. Schneider
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
| | - Lisa D. Cabrita
- Institute of Structural and Molecular Biology, University College London and Birkbeck College, London WC1 6BT, UK
| | - John Christodoulou
- Institute of Structural and Molecular Biology, University College London and Birkbeck College, London WC1 6BT, UK
| | - Tuomas P. J. Knowles
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, UK
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4
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Roeselová A, Maslen SL, Shivakumaraswamy S, Pellowe GA, Howell S, Joshi D, Redmond J, Kjær S, Skehel JM, Balchin D. Mechanism of chaperone coordination during cotranslational protein folding in bacteria. Mol Cell 2024; 84:2455-2471.e8. [PMID: 38908370 DOI: 10.1016/j.molcel.2024.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 04/12/2024] [Accepted: 06/01/2024] [Indexed: 06/24/2024]
Abstract
Protein folding is assisted by molecular chaperones that bind nascent polypeptides during mRNA translation. Several structurally distinct classes of chaperones promote de novo folding, suggesting that their activities are coordinated at the ribosome. We used biochemical reconstitution and structural proteomics to explore the molecular basis for cotranslational chaperone action in bacteria. We found that chaperone binding is disfavored close to the ribosome, allowing folding to precede chaperone recruitment. Trigger factor recognizes compact folding intermediates that expose an extensive unfolded surface, and dictates DnaJ access to nascent chains. DnaJ uses a large surface to bind structurally diverse intermediates and recruits DnaK to sequence-diverse solvent-accessible sites. Neither Trigger factor, DnaJ, nor DnaK destabilize cotranslational folding intermediates. Instead, the chaperones collaborate to protect incipient structure in the nascent polypeptide well beyond the ribosome exit tunnel. Our findings show how the chaperone network selects and modulates cotranslational folding intermediates.
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Affiliation(s)
- Alžběta Roeselová
- Protein Biogenesis Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Sarah L Maslen
- Proteomics Science Technology Platform, The Francis Crick Institute, London NW1 1AT, UK
| | | | - Grant A Pellowe
- Protein Biogenesis Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Steven Howell
- Proteomics Science Technology Platform, The Francis Crick Institute, London NW1 1AT, UK
| | - Dhira Joshi
- Chemical Biology Science Technology Platform, The Francis Crick Institute, London NW1 1AT, UK
| | - Joanna Redmond
- Chemical Biology Science Technology Platform, The Francis Crick Institute, London NW1 1AT, UK
| | - Svend Kjær
- Structural Biology Science Technology Platform, The Francis Crick Institute, London NW1 1AT, UK
| | - J Mark Skehel
- Proteomics Science Technology Platform, The Francis Crick Institute, London NW1 1AT, UK
| | - David Balchin
- Protein Biogenesis Laboratory, The Francis Crick Institute, London NW1 1AT, UK.
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5
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Wales TE, Pajak A, Roeselová A, Shivakumaraswamy S, Howell S, Kjær S, Hartl FU, Engen JR, Balchin D. Resolving chaperone-assisted protein folding on the ribosome at the peptide level. Nat Struct Mol Biol 2024:10.1038/s41594-024-01355-x. [PMID: 38987455 DOI: 10.1038/s41594-024-01355-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 06/17/2024] [Indexed: 07/12/2024]
Abstract
Protein folding in vivo begins during synthesis on the ribosome and is modulated by molecular chaperones that engage the nascent polypeptide. How these features of protein biogenesis influence the maturation pathway of nascent proteins is incompletely understood. Here, we use hydrogen-deuterium exchange mass spectrometry to define, at peptide resolution, the cotranslational chaperone-assisted folding pathway of Escherichia coli dihydrofolate reductase. The nascent polypeptide folds along an unanticipated pathway through structured intermediates not populated during refolding from denaturant. Association with the ribosome allows these intermediates to form, as otherwise destabilizing carboxy-terminal sequences remain confined in the ribosome exit tunnel. Trigger factor binds partially folded states without disrupting their structure, and the nascent chain is poised to complete folding immediately upon emergence of the C terminus from the exit tunnel. By mapping interactions between the nascent chain and ribosomal proteins, we trace the path of the emerging polypeptide during synthesis. Our work reveals new mechanisms by which cellular factors shape the conformational search for the native state.
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Affiliation(s)
- Thomas E Wales
- Department of Chemistry & Chemical Biology, Northeastern University, Boston, MA, USA
| | - Aleksandra Pajak
- Protein Biogenesis Laboratory, The Francis Crick Institute, London, UK
| | - Alžběta Roeselová
- Protein Biogenesis Laboratory, The Francis Crick Institute, London, UK
| | | | - Steven Howell
- Proteomics Science Technology Platform, The Francis Crick Institute, London, UK
| | - Svend Kjær
- Structural Biology Science Technology Platform, The Francis Crick Institute, London, UK
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - John R Engen
- Department of Chemistry & Chemical Biology, Northeastern University, Boston, MA, USA.
| | - David Balchin
- Protein Biogenesis Laboratory, The Francis Crick Institute, London, UK.
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6
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Rajasekaran N, Kaiser CM. Navigating the complexities of multi-domain protein folding. Curr Opin Struct Biol 2024; 86:102790. [PMID: 38432063 DOI: 10.1016/j.sbi.2024.102790] [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: 11/27/2023] [Revised: 02/11/2024] [Accepted: 02/12/2024] [Indexed: 03/05/2024]
Abstract
Proteome complexity has expanded tremendously over evolutionary time, enabling biological diversification. Much of this complexity is achieved by combining a limited set of structural units into long polypeptides. This widely used evolutionary strategy poses challenges for folding of the resulting multi-domain proteins. As a consequence, their folding differs from that of small single-domain proteins, which generally fold quickly and reversibly. Co-translational processes and chaperone interactions are important aspects of multi-domain protein folding. In this review, we discuss some of the recent experimental progress toward understanding these processes.
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Affiliation(s)
| | - Christian M Kaiser
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States; Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, Netherlands.
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7
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McDonnell RT, Elcock AH. AutoRNC: An automated modeling program for building atomic models of ribosome-nascent chain complexes. Structure 2024; 32:621-629.e5. [PMID: 38428431 PMCID: PMC11073581 DOI: 10.1016/j.str.2024.02.002] [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: 06/30/2023] [Revised: 11/29/2023] [Accepted: 02/05/2024] [Indexed: 03/03/2024]
Abstract
The interpretation of experimental studies of co-translational protein folding often benefits from the use of computational methods that seek to model or simulate the nascent chain and its interactions with the ribosome. Building realistic 3D models of ribosome-nascent chain (RNC) constructs often requires expert knowledge, so to circumvent this issue, we describe here AutoRNC, an automated modeling program capable of constructing large numbers of plausible atomic models of RNCs within minutes. AutoRNC takes input from the user specifying any regions of the nascent chain that contain secondary or tertiary structure and attempts to build conformations compatible with those specifications-and with the constraints imposed by the ribosome-by sampling and progressively piecing together dipeptide conformations extracted from the Research Collaboratory for Structural Bioinformatics Protein Data Bank (RCSB). Despite using only modest computational resources, we show here that AutoRNC can build plausible conformations for a wide range of RNC constructs for which experimental data have already been reported.
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Affiliation(s)
- Robert T McDonnell
- Department of Biochemistry & Molecular Biology, University of Iowa, Iowa City, IA, USA
| | - Adrian H Elcock
- Department of Biochemistry & Molecular Biology, University of Iowa, Iowa City, IA, USA.
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8
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Gersteuer F, Morici M, Gabrielli S, Fujiwara K, Safdari HA, Paternoga H, Bock LV, Chiba S, Wilson DN. The SecM arrest peptide traps a pre-peptide bond formation state of the ribosome. Nat Commun 2024; 15:2431. [PMID: 38503753 PMCID: PMC10951299 DOI: 10.1038/s41467-024-46762-2] [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: 10/30/2023] [Accepted: 03/07/2024] [Indexed: 03/21/2024] Open
Abstract
Nascent polypeptide chains can induce translational stalling to regulate gene expression. This is exemplified by the E. coli secretion monitor (SecM) arrest peptide that induces translational stalling to regulate expression of the downstream encoded SecA, an ATPase that co-operates with the SecYEG translocon to facilitate insertion of proteins into or through the cytoplasmic membrane. Here we present the structure of a ribosome stalled during translation of the full-length E. coli SecM arrest peptide at 2.0 Å resolution. The structure reveals that SecM arrests translation by stabilizing the Pro-tRNA in the A-site, but in a manner that prevents peptide bond formation with the SecM-peptidyl-tRNA in the P-site. By employing molecular dynamic simulations, we also provide insight into how a pulling force on the SecM nascent chain can relieve the SecM-mediated translation arrest. Collectively, the mechanisms determined here for SecM arrest and relief are also likely to be applicable for a variety of other arrest peptides that regulate components of the protein localization machinery identified across a wide range of bacteria lineages.
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Affiliation(s)
- Felix Gersteuer
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Martino Morici
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Sara Gabrielli
- Theoretical and Computational Biophysics Department, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Keigo Fujiwara
- Faculty of Life Sciences and Institute for Protein Dynamics, Kyoto Sangyo University, Kamigamo, Motoyama, Kita-ku, Kyoto, 603-8555, Japan
| | - Haaris A Safdari
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Helge Paternoga
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany
| | - Lars V Bock
- Theoretical and Computational Biophysics Department, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Shinobu Chiba
- Faculty of Life Sciences and Institute for Protein Dynamics, Kyoto Sangyo University, Kamigamo, Motoyama, Kita-ku, Kyoto, 603-8555, Japan
| | - Daniel N Wilson
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany.
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9
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Samatova E, Komar AA, Rodnina MV. How the ribosome shapes cotranslational protein folding. Curr Opin Struct Biol 2024; 84:102740. [PMID: 38071940 DOI: 10.1016/j.sbi.2023.102740] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/15/2023] [Accepted: 11/16/2023] [Indexed: 02/09/2024]
Abstract
During protein synthesis, the growing nascent peptide chain moves inside the polypeptide exit tunnel of the ribosome from the peptidyl transferase center towards the exit port where it emerges into the cytoplasm. The ribosome defines the unique energy landscape of the pioneering round of protein folding. The spatial confinement and the interactions of the nascent peptide with the tunnel walls facilitate formation of secondary structures, such as α-helices. The vectorial nature of protein folding inside the tunnel favors local intra- and inter-molecular interactions, thereby inducing cotranslational folding intermediates that do not form upon protein refolding in solution. Tertiary structures start to fold in the lower part of the tunnel, where interactions with the ribosome destabilize native protein folds. The present review summarizes the recent progress in understanding the driving forces of nascent protein folding inside the tunnel and at the surface of the ribosome.
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Affiliation(s)
- Ekaterina Samatova
- Department of Physical Biochemistry, Max Planck Institute for Multidisciplinary Sciences, Goettingen 37077, Germany
| | - Anton A Komar
- Center for Gene Regulation in Health and Disease, Department of Biological, Geological and Environmental Sciences, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA; Department of Biochemistry and Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Multidisciplinary Sciences, Goettingen 37077, Germany.
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10
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Panda C, Kumar S, Gupta S, Pandey LM. Structural, kinetic, and thermodynamic aspects of insulin aggregation. Phys Chem Chem Phys 2023; 25:24195-24213. [PMID: 37674360 DOI: 10.1039/d3cp03103a] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Given the significance of protein aggregation in proteinopathies and the development of therapeutic protein pharmaceuticals, revamped interest in assessing and modelling the aggregation kinetics has been observed. Quantitative analysis of aggregation includes data of gradual monomeric depletion followed by the formation of subvisible particles. Kinetic and thermodynamic studies are essential to gain key insights into the aggregation process. Despite being the medical marvel in the world of diabetes, insulin suffers from the challenge of aggregation. Physicochemical stresses are experienced by insulin during industrial formulation, storage, delivery, and transport, considerably impacting product quality, efficacy, and effectiveness. The present review briefly describes the pathways, mathematical kinetic models, and thermodynamics of protein misfolding and aggregation. With a specific focus on insulin, further discussions include the structural heterogeneity and modifications of the intermediates incurred during insulin fibrillation. Finally, different model equations to fit the kinetic data of insulin fibrillation are discussed. We believe that this review will shed light on the conditions that induce structural changes in insulin during the lag phase of fibrillation and will motivate scientists to devise strategies to block the initialization of the aggregation cascade. Subsequent abrogation of insulin fibrillation during bioprocessing will ensure stable and globally accessible insulin for efficient management of diabetes.
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Affiliation(s)
- Chinmaya Panda
- Bio-interface & Environmental Engineering Lab Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Assam, 781039, India.
| | - Sachin Kumar
- Viral Immunology Lab Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Assam, 781039, India
| | - Sharad Gupta
- Neurodegeneration and Peptide Engineering Research Lab Biological Engineering Discipline, Indian Institute of Technology Gandhinagar, Gujarat, 382355, India
| | - Lalit M Pandey
- Bio-interface & Environmental Engineering Lab Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Assam, 781039, India.
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11
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Chen X, Kaiser CM. AP profiling resolves co-translational folding pathway and chaperone interactions in vivo. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.01.555749. [PMID: 37693575 PMCID: PMC10491307 DOI: 10.1101/2023.09.01.555749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Natural proteins have evolved to fold robustly along specific pathways. Folding begins during synthesis, guided by interactions of the nascent protein with the ribosome and molecular chaperones. However, the timing and progression of co-translational folding remain largely elusive, in part because the process is difficult to measure in the natural environment of the cytosol. We developed a high-throughput method to quantify co-translational folding in live cells that we term Arrest Peptide profiling (AP profiling). We employed AP profiling to delineate co-translational folding for a set of GTPase domains with very similar structures, defining how topology shapes folding pathways. Genetic ablation of major nascent chain-binding chaperones resulted in localized folding changes that suggest how functional redundancies among chaperones are achieved by distinct interactions with the nascent protein. Collectively, our studies provide a window into cellular folding pathways of complex proteins and pave the way for systematic studies on nascent protein folding at unprecedented resolution and throughput.
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Affiliation(s)
- Xiuqi Chen
- CMDB Graduate Program, Johns Hopkins University, Baltimore, MD, United States
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States
- Present address: Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, the Netherlands
| | - Christian M. Kaiser
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States
- Department of Biophysics, Johns Hopkins University, Baltimore, MD, United States
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12
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McDonnell RT, Elcock AH. AutoRNC: an automated modeling program for building atomic models of ribosome-nascent chain complexes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.14.544999. [PMID: 37398297 PMCID: PMC10312685 DOI: 10.1101/2023.06.14.544999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
The interpretation of experimental studies of co-translational protein folding often benefits from the use of computational methods that seek to model the nascent chain and its interactions with the ribosome. Ribosome-nascent chain (RNC) constructs studied experimentally can vary significantly in size and the extent to which they contain secondary and tertiary structure, and building realistic 3D models of them therefore often requires expert knowledge. To circumvent this issue, we describe here AutoRNC, an automated modeling program capable of constructing large numbers of plausible atomic models of RNCs within minutes. AutoRNC takes input from the user specifying any regions of the nascent chain that contain secondary or tertiary structure and attempts to build conformations compatible with those specifications - and with the constraints imposed by the ribosome - by sampling and progressively piecing together dipeptide conformations extracted from the RCSB. We first show that conformations of completely unfolded proteins built by AutoRNC in the absence of the ribosome have radii of gyration that match well with the corresponding experimental data. We then show that AutoRNC can build plausible conformations for a wide range of RNC constructs for which experimental data have already been reported. Since AutoRNC requires only modest computational resources, we anticipate that it will prove to be a useful hypothesis generator for experimental studies, for example, in providing indications of whether designed constructs are likely to be capable of folding, as well as providing useful starting points for downstream atomic or coarse-grained simulations of the conformational dynamics of RNCs.
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13
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Neira JL, Palomino-Schätzlein M. Folding of the nascent polypeptide chain of a histidine phosphocarrier protein in vitro. Arch Biochem Biophys 2023; 736:109538. [PMID: 36738980 DOI: 10.1016/j.abb.2023.109538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/28/2023] [Accepted: 02/01/2023] [Indexed: 02/05/2023]
Abstract
The phosphotransferase system (PTS), a metabolic pathway formed by five proteins, modulates the use of sugars in bacteria. The second protein in the chain is the histidine phosphocarrier, HPr, with the binding site at His15. The HPr kinase/phosphorylase (HPrK/P), involved in the bacterial use of carbon sources, phosphorylates HPr at Ser46, and it binds at its binding site. The regulator of sigma D protein (Rsd) also binds to HPr at His15. We have designed fragments of HPr, growing from its N-terminus and containing the His15. In this work, we obtained three fragments, HPr38, HPr58 and HPr70, comprising the first thirty-eight, fifty-eight and seventy residues of HPr, respectively. All fragments were mainly disordered, with evidence of a weak native-like, helical population around the binding site, as shown by fluorescence, far-ultraviolet circular dichroism, size exclusion chromatography and nuclear magnetic resonance. Although HPr38, HPr58 and HPr70 were disordered, they could bind to: (i) the N-terminal domain of first protein of the PTS, EIN; (ii) Rsd; and, (iii) HPrK/P, as shown by fluorescence and biolayer interferometry (BLI). The association constants for each protein to any of the fragments were in the low micromolar range, within the same range than those measured in the binding of HPr to each protein. Then, although acquisition of stable, native-like secondary and tertiary structures occurred at the last residues of the polypeptide, the ability to bind protein partners happened much earlier in the growing chain. Binding was related to the presence of the native-like structure around His15.
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Affiliation(s)
- José L Neira
- IDIBE, Universidad Miguel Hernández, 03202, Elche, Alicante, Spain; Instituto de Biocomputación y Física de Sistemas Complejos (BIFI), Joint Units IQFR-CSIC-BIFI and GBsC-CSIC-BIFI, Universidad de Zaragoza, 50018, Zaragoza, Spain.
| | - Martina Palomino-Schätzlein
- ProtoQSAR SL, CEEI-Valencia, Parque Tecnológico de Valencia, Av. Benjamin Franklin 12 (Dep. 8), 46980, Paterna, Valencia, Spain
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