1
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Dupuy E, Collet JF. Entering deeper into the mysteries of the GroEL-GroES nanomachine. Curr Opin Microbiol 2024; 79:102480. [PMID: 38714141 DOI: 10.1016/j.mib.2024.102480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 04/10/2024] [Accepted: 04/12/2024] [Indexed: 05/09/2024]
Abstract
In the densely populated intracellular milieu, polypeptides are at constant risk of nonspecific interactions and aggregation, posing a threat to essential cellular functions. Cells rely on a network of protein folding factors to deal with this challenge. The Hsp60 family of molecular chaperones, which depend on ATP for function, stands out in the proteostasis network by a characteristic structure comprising two multimeric rings arranged back to back. This review provides an updated overview of GroEL, the bacterial Hsp60, and its GroES (Hsp10) cofactor. Specifically, we highlight recent breakthroughs in understanding the intricate folding mechanisms of the GroEL-GroES nanomachine and explore the newly discovered interaction between GroEL and the chaperedoxin CnoX. Despite considerable research on the GroEL-GroES system, numerous questions remain to be explored.
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Affiliation(s)
- Emile Dupuy
- WELBIO department, WEL Research Institute, Avenue Pasteur 6, 1300 Wavre, Belgium; de Duve Institute, Université catholique de Louvain, Avenue Hippocrate 75, 1200 Brussels, Belgium
| | - Jean-François Collet
- WELBIO department, WEL Research Institute, Avenue Pasteur 6, 1300 Wavre, Belgium; de Duve Institute, Université catholique de Louvain, Avenue Hippocrate 75, 1200 Brussels, Belgium.
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2
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Gardner S, Darrow MC, Lukoyanova N, Thalassinos K, Saibil HR. Structural basis of substrate progression through the bacterial chaperonin cycle. Proc Natl Acad Sci U S A 2023; 120:e2308933120. [PMID: 38064510 PMCID: PMC10723157 DOI: 10.1073/pnas.2308933120] [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: 05/31/2023] [Accepted: 10/20/2023] [Indexed: 12/17/2023] Open
Abstract
The bacterial chaperonin GroEL-GroES promotes protein folding through ATP-regulated cycles of substrate protein binding, encapsulation, and release. Here, we have used cryoEM to determine structures of GroEL, GroEL-ADP·BeF3, and GroEL-ADP·AlF3-GroES all complexed with the model substrate Rubisco. Our structures provide a series of snapshots that show how the conformation and interactions of non-native Rubisco change as it proceeds through the GroEL-GroES reaction cycle. We observe specific charged and hydrophobic GroEL residues forming strong initial contacts with non-native Rubisco. Binding of ATP or ADP·BeF3 to GroEL-Rubisco results in the formation of an intermediate GroEL complex displaying striking asymmetry in the ATP/ADP·BeF3-bound ring. In this ring, four GroEL subunits bind Rubisco and the other three are in the GroES-accepting conformation, suggesting how GroEL can recruit GroES without releasing bound substrate. Our cryoEM structures of stalled GroEL-ADP·AlF3-Rubisco-GroES complexes show Rubisco folding intermediates interacting with GroEL-GroES via different sets of residues.
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Affiliation(s)
- Scott Gardner
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, LondonWC1E 7HX, United Kingdom
| | | | - Natalya Lukoyanova
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, LondonWC1E 7HX, United Kingdom
| | - Konstantinos Thalassinos
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, LondonWC1E 7HX, United Kingdom
- Division of Biosciences, Institute of Structural and Molecular Biology, University College London, LondonWC1E 6BT, United Kingdom
| | - Helen R. Saibil
- Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, LondonWC1E 7HX, United Kingdom
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3
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Piplani B, Kumar CMS, Lund PA, Chaudhuri TK. Mycobacterial chaperonins in cellular proteostasis: Evidence for chaperone function of Cpn60.1 and Cpn60.2-mediated protein folding. Mol Microbiol 2023; 120:210-223. [PMID: 37350285 PMCID: PMC10952152 DOI: 10.1111/mmi.15109] [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: 12/14/2022] [Revised: 06/04/2023] [Accepted: 06/06/2023] [Indexed: 06/24/2023]
Abstract
Mycobacterium tuberculosis encodes two chaperonin proteins, MtbCpn60.1 and MtbCpn60.2, that share substantial sequence similarity with the Escherichia coli chaperonin, GroEL. However, unlike GroEL, MtbCpn60.1 and MtbCpn60.2 purify as lower-order oligomers. Previous studies have shown that MtbCpn60.2 can functionally replace GroEL in E. coli, while the function of MtbCpn60.1 remained an enigma. Here, we demonstrate the molecular chaperone function of MtbCpn60.1 and MtbCpn60.2, by probing their ability to assist the folding of obligate chaperonin clients, DapA, FtsE and MetK, in an E. coli strain depleted of endogenous GroEL. We show that both MtbCpn60.1 and MtbCpn60.2 support cell survival and cell division by assisting the folding of DapA and FtsE, but only MtbCpn60.2 completely rescues GroEL-depleted E. coli cells. We also show that, unlike MtbCpn60.2, MtbCpn60.1 has limited ability to support cell growth and proliferation and assist the folding of MetK. Our findings suggest that the client pools of GroEL and MtbCpn60.2 overlap substantially, while MtbCpn60.1 folds only a small subset of GroEL clients. We conclude that the differences between MtbCpn60.1 and MtbCpn60.2 may be a consequence of their intrinsic sequence features, which affect their thermostability, efficiency, clientomes and modes of action.
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Affiliation(s)
- Bakul Piplani
- Kusuma School of Biological SciencesIndian Institute of Technology DelhiIndia
| | - C. M. Santosh Kumar
- School of BiosciencesUniversity of BirminghamBirmingham
- Institute of Microbiology and InfectionUniversity of BirminghamBirminghamUK
| | - Peter A. Lund
- School of BiosciencesUniversity of BirminghamBirmingham
- Institute of Microbiology and InfectionUniversity of BirminghamBirminghamUK
| | - Tapan K. Chaudhuri
- Kusuma School of Biological SciencesIndian Institute of Technology DelhiIndia
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A diminished hydrophobic effect inside the GroEL/ES cavity contributes to protein substrate destabilization. Proc Natl Acad Sci U S A 2022; 119:e2213170119. [PMID: 36409898 PMCID: PMC9860310 DOI: 10.1073/pnas.2213170119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Confining compartments are ubiquitous in biology, but there have been few experimental studies on the thermodynamics of protein folding in such environments. Recently, we reported that the stability of a model protein substrate in the GroEL/ES chaperonin cage is reduced dramatically by more than 5 kcal mol-1 compared to that in bulk solution, but the origin of this effect remained unclear. Here, we show that this destabilization is caused, at least in part, by a diminished hydrophobic effect in the GroEL/ES cavity. This reduced hydrophobic effect is probably caused by water ordering due to the small number of hydration shells between the cavity and protein substrate surfaces. Hence, encapsulated protein substrates can undergo a process similar to cold denaturation in which unfolding is promoted by ordered water molecules. Our findings are likely to be relevant to encapsulated substrates in chaperonin systems, in general, and are consistent with the iterative annealing mechanism of action proposed for GroEL/ES.
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5
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Shoup D, Roth A, Puchalla J, Rye HS. The Impact of Hidden Structure on Aggregate Disassembly by Molecular Chaperones. Front Mol Biosci 2022; 9:915307. [PMID: 35874607 PMCID: PMC9302491 DOI: 10.3389/fmolb.2022.915307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 06/16/2022] [Indexed: 11/13/2022] Open
Abstract
Protein aggregation, or the uncontrolled self-assembly of partially folded proteins, is an ever-present danger for living organisms. Unimpeded, protein aggregation can result in severe cellular dysfunction and disease. A group of proteins known as molecular chaperones is responsible for dismantling protein aggregates. However, how protein aggregates are recognized and disassembled remains poorly understood. Here we employ a single particle fluorescence technique known as Burst Analysis Spectroscopy (BAS), in combination with two structurally distinct aggregate types grown from the same starting protein, to examine the mechanism of chaperone-mediated protein disaggregation. Using the core bi-chaperone disaggregase system from Escherichia coli as a model, we demonstrate that, in contrast to prevailing models, the overall size of an aggregate particle has, at most, a minor influence on the progression of aggregate disassembly. Rather, we show that changes in internal structure, which have no observable impact on aggregate particle size or molecular chaperone binding, can dramatically limit the ability of the bi-chaperone system to take aggregates apart. In addition, these structural alterations progress with surprising speed, rendering aggregates resistant to disassembly within minutes. Thus, while protein aggregate structure is generally poorly defined and is often obscured by heterogeneous and complex particle distributions, it can have a determinative impact on the ability of cellular quality control systems to process protein aggregates.
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Affiliation(s)
- Daniel Shoup
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States
| | - Andrew Roth
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States
| | - Jason Puchalla
- Department of Physics, Princeton University, Princeton, NJ, United States
| | - Hays S. Rye
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States
- *Correspondence: Hays S. Rye,
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6
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Naqvi MM, Avellaneda MJ, Roth A, Koers EJ, Roland A, Sunderlikova V, Kramer G, Rye HS, Tans SJ. Protein chain collapse modulation and folding stimulation by GroEL-ES. SCIENCE ADVANCES 2022; 8:eabl6293. [PMID: 35245117 PMCID: PMC8896798 DOI: 10.1126/sciadv.abl6293] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 01/11/2022] [Indexed: 06/14/2023]
Abstract
The collapse of polypeptides is thought important to protein folding, aggregation, intrinsic disorder, and phase separation. However, whether polypeptide collapse is modulated in cells to control protein states is unclear. Here, using integrated protein manipulation and imaging, we show that the chaperonin GroEL-ES can accelerate the folding of proteins by strengthening their collapse. GroEL induces contractile forces in substrate chains, which draws them into the cavity and triggers a general compaction and discrete folding transitions, even for slow-folding proteins. This collapse enhancement is strongest in the nucleotide-bound states of GroEL and is aided by GroES binding to the cavity rim and by the amphiphilic C-terminal tails at the cavity bottom. Collapse modulation is distinct from other proposed GroEL-ES folding acceleration mechanisms, including steric confinement and misfold unfolding. Given the prevalence of collapse throughout the proteome, we conjecture that collapse modulation is more generally relevant within the protein quality control machinery.
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Affiliation(s)
| | | | - Andrew Roth
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77845, USA
| | | | | | | | - Günter Kramer
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, Heidelberg D-69120, Germany
- German Cancer Research Center (DKFZ), Im Neuenheimer Feld 282, Heidelberg D-69120, Germany
| | - Hays S. Rye
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77845, USA
| | - Sander J. Tans
- AMOLF, Science Park 104, 1098 XG Amsterdam, Netherlands
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, Netherlands
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7
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Kim H, Park J, Lim S, Jun SH, Jung M, Roh SH. Cryo-EM structures of GroEL:ES 2 with RuBisCO visualize molecular contacts of encapsulated substrates in a double-cage chaperonin. iScience 2022; 25:103704. [PMID: 35036883 PMCID: PMC8749442 DOI: 10.1016/j.isci.2021.103704] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 11/12/2021] [Accepted: 12/23/2021] [Indexed: 10/24/2022] Open
Abstract
The GroEL/GroES chaperonin system assists the folding of many proteins, through conformational transitions driven by ATP hydrolysis. Although structural information about bullet-shaped GroEL:ES1 complexes has been extensively reported, the substrate interactions of another functional complex, the football-shaped GroEL:ES2, remain elusive. Here, we report single-particle cryo-EM structures of reconstituted wild-type GroEL:ES2 complexes with a chemically denatured substrate, ribulose-1,5-bisphosphate carboxylase oxygenase (RuBisCO). Our structures demonstrate that native-like folded RuBisCO density is captured at the lower part of the GroEL chamber and that GroEL's bulky hydrophobic residues Phe281, Tyr360, and Phe44 contribute to direct contact with RuBisCO density. In addition, our analysis found that GroEL:ES2 can be occupied by two substrates simultaneously, one in each chamber. Together, these observations provide insights to the football-shaped GroEL:ES2 complex as a functional state to assist the substrate folding with visualization.
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Affiliation(s)
- Hyunmin Kim
- School of Biology, Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, Republic of Korea
| | - Junsun Park
- School of Biology, Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, Republic of Korea
| | - Seyeon Lim
- School of Biology, Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, Republic of Korea
| | - Sung-Hoon Jun
- Korea Basic Science Institute, Ochang 28119, Republic of Korea
| | - Mingyu Jung
- School of Biology, Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, Republic of Korea
| | - Soung-Hun Roh
- School of Biology, Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, Republic of Korea
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Horovitz A, Reingewertz TH, Cuéllar J, Valpuesta JM. Chaperonin Mechanisms: Multiple and (Mis)Understood? Annu Rev Biophys 2022; 51:115-133. [DOI: 10.1146/annurev-biophys-082521-113418] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The chaperonins are ubiquitous and essential nanomachines that assist in protein folding in an ATP-driven manner. They consist of two back-to-back stacked oligomeric rings with cavities in which protein (un)folding can take place in a shielding environment. This review focuses on GroEL from Escherichia coli and the eukaryotic chaperonin-containing t-complex polypeptide 1, which differ considerably in their reaction mechanisms despite sharing a similar overall architecture. Although chaperonins feature in many current biochemistry textbooks after being studied intensively for more than three decades, key aspects of their reaction mechanisms remain under debate and are discussed in this review. In particular, it is unclear whether a universal reaction mechanism operates for all substrates and whether it is passive, i.e., aggregation is prevented but the folding pathway is unaltered, or active. It is also unclear how chaperonin clients are distinguished from nonclients and what are the precise roles of the cofactors with which chaperonins interact. Expected final online publication date for the Annual Review of Biophysics, Volume 51 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Amnon Horovitz
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel; Amnon.H
| | - Tali Haviv Reingewertz
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, Israel; Amnon.H
| | - Jorge Cuéllar
- Department of Macromolecular Structure, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
| | - José María Valpuesta
- Department of Macromolecular Structure, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
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Kaewchana A, Techaparin A, Boonchot N, Thanonkeo P, Klanrit P. Improved high-temperature ethanol production from sweet sorghum juice using Zymomonas mobilis overexpressing groESL genes. Appl Microbiol Biotechnol 2021; 105:9419-9431. [PMID: 34787692 DOI: 10.1007/s00253-021-11686-0] [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: 01/28/2021] [Revised: 10/11/2021] [Accepted: 11/07/2021] [Indexed: 10/19/2022]
Abstract
Zymomonas mobilis may encounter various types of stress during ethanol fermentation, which reduces ethanol production efficiency. This situation may be mitigated by molecular chaperones, including the chaperonin GroESL, which confers enhanced protection against various stresses. In this study, we successfully developed a Z. mobilis strain R301 that harbors groESL genes and can be used for high-temperature ethanol production from sweet sorghum juice. Sequence analyses of GroES and GroEL from Z. mobilis TISTR548 demonstrated conserved residues at specific positions within GroES and conserved glycine-glycine-methionine (GGM) repeats at the C-terminus of GroEL. The Z. mobilis wild-type and R301 strains were then evaluated for their tolerance to stresses, including high temperatures, high sugar concentrations, and high ethanol concentrations up to 40°C, 300 g/L, and 13% (v/v), respectively. Z. mobilis R301 exhibited better growth performance than the wild-type strain under all stress conditions. This is the first report on ethanol production at 40°C by recombinant Z. mobilis using sweet sorghum juice; this strain produced an ethanol concentration of 41.66 g/L, with a productivity of 0.87 g/L/h and a theoretical ethanol yield of 88.9%. Overexpression of groESL resulted in increased ethanol production, with values approximately 11% higher than those of the wild type at 40°C. Additionally, at 37°C, Z. mobilis R301 gave a higher theoretical ethanol yield (92.6%) than that shown in previous research. This work illustrates the potential for future enhancement of industrial-scale ethanol production at high temperatures utilizing Z. mobilis R301 in the bioconversion of sweet sorghum juice, a promising energy crop. KEY POINTS: • The groESL-overexpressing Z. mobilis strain was successfully constructed. • The recombinant Z. mobilis exhibited higher stress tolerance than the wild-type strain. • Overexpression of groESL genes improved ethanol production efficiency at high temperatures.
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Affiliation(s)
- Anchittha Kaewchana
- Graduate School, Khon Kaen University, Khon Kaen, 40002, Thailand.,Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen, 40002, Thailand
| | - Atiya Techaparin
- Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen, 40002, Thailand
| | - Nongluck Boonchot
- Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen, 40002, Thailand
| | - Pornthap Thanonkeo
- Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen, 40002, Thailand.,Fermentation Research Center for Value Added Agricultural Products (FerVAAP), Khon Kaen University, Khon Kaen, 40002, Thailand
| | - Preekamol Klanrit
- Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen, 40002, Thailand. .,Fermentation Research Center for Value Added Agricultural Products (FerVAAP), Khon Kaen University, Khon Kaen, 40002, Thailand.
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Structural and Computational Study of the GroEL-Prion Protein Complex. Biomedicines 2021; 9:biomedicines9111649. [PMID: 34829878 PMCID: PMC8615626 DOI: 10.3390/biomedicines9111649] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/02/2021] [Accepted: 11/05/2021] [Indexed: 11/16/2022] Open
Abstract
The molecular chaperone GroEL is designed to promote protein folding and prevent aggregation. However, the interaction between GroEL and the prion protein, PrPC, could lead to pathogenic transformation of the latter to the aggregation-prone PrPSc form. Here, the molecular basis of the interactions in the GroEL-PrP complex is studied with cryo-EM and molecular dynamics approaches. The obtained cryo-EM structure shows PrP to be bound to several subunits of GroEL at the level of their apical domains. According to MD simulations, the disordered N-domain of PrP forms much more intermolecular contacts with GroEL. Upon binding to the GroEL, the N-domain of PrP begins to form short helices, while the C-domain of PrP exhibits a tendency to unfold its α2-helix. In the absence of the nucleotides in the system, these processes are manifested at the hundred nanoseconds to microsecond timescale.
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Panina IS, Mamchur AA, Yaroshevich IA, Zlenko DV, Pichkur EB, Kudryavtseva SS, Muronetz VI, Sokolova OS, Stanishneva-Konovalova TB. Study of GroEL Conformational Mobility by Cryo-Electron Microscopy and Molecular Dynamics. CRYSTALLOGR REP+ 2021. [DOI: 10.1134/s1063774521050163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Abstract
Bacterial chaperonin GroEL is a complex ring-shaped protein oligomer that promotes the folding of other proteins by encapsulating them in the cavity. There is very little structural information about the disordered C-terminal fragment of the GroEL subunits, which is involved in the folding of the substrate protein. A 3D reconstruction of the GroEL apo-form was obtained by cryo-electron microscopy (cryo-EM) with a resolution of 3.02 Å and supplemented by molecular dynamics (MD) calculations. The results of cryo-EM and MD are in good agreement and demonstrate a diverse mobility of the protein subunit domains. The MD results predict the dynamics and the network of intramolecular contacts of the C-terminal sections of the protein. These results are of great importance for the subsequent study of the mechanism of protein folding in the GroEL cavity.
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Abstract
As the GroES/GroEL chaperonin system is the only bacterial chaperone that is essential under all conditions, we have been interested in the development of GroES/GroEL inhibitors as potential antibiotics. Using Escherichia coli GroES/GroEL as a surrogate, we have discovered several classes of GroES/GroEL inhibitors that show potent antibacterial activity against both Gram-positive and Gram-negative bacteria. However, it remains unknown if E. coli GroES/GroEL is functionally identical to other GroES/GroEL chaperonins and hence if our inhibitors will function against other chaperonins. Herein we report our initial efforts to characterize the GroES/GroEL chaperonins from clinically significant ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species). We used complementation experiments in GroES/GroEL-deficient and -null E. coli strains to report on exogenous ESKAPE chaperone function. In GroES/GroEL-deficient (but not knocked-out) E. coli, we found that only a subset of the ESKAPE GroES/GroEL chaperone systems could complement to produce a viable organism. Surprisingly, GroES/GroEL chaperone systems from two of the ESKAPE pathogens were found to complement in E. coli, but only in the strict absence of either E. coli GroEL (P. aeruginosa) or both E. coli GroES and GroEL (E. faecium). In addition, GroES/GroEL from S. aureus was unable to complement E. coli GroES/GroEL under all conditions. The resulting viable strains, in which E. coli groESL was replaced with ESKAPE groESL, demonstrated similar growth kinetics to wild-type E. coli, but displayed an elongated phenotype (potentially indicating compromised GroEL function) at some temperatures. These results suggest functional differences between GroES/GroEL chaperonins despite high conservation of amino acid identity.IMPORTANCE The GroES/GroEL chaperonin from E. coli has long served as the model system for other chaperonins. This assumption seemed valid because of the high conservation between the chaperonins. It was, therefore, shocking to discover ESKAPE pathogen GroES/GroEL formed mixed-complex chaperonins in the presence of E. coli GroES/GroEL, leading to loss of organism viability in some cases. Complete replacement of E. coli groESL with ESKAPE groESL restored organism viability, but produced an elongated phenotype, suggesting differences in chaperonin function, including client specificity and/or refolding cycle rates. These data offer important mechanistic insight into these remarkable machines, and the new strains developed allow for the synthesis of homogeneous chaperonins for biochemical studies and to further our efforts to develop chaperonin-targeted antibiotics.
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Korobko I, Mazal H, Haran G, Horovitz A. Measuring protein stability in the GroEL chaperonin cage reveals massive destabilization. eLife 2020; 9:56511. [PMID: 32716842 PMCID: PMC7440923 DOI: 10.7554/elife.56511] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 07/25/2020] [Indexed: 01/29/2023] Open
Abstract
The thermodynamics of protein folding in bulk solution have been thoroughly investigated for decades. By contrast, measurements of protein substrate stability inside the GroEL/ES chaperonin cage have not been reported. Such measurements require stable encapsulation, that is no escape of the substrate into bulk solution during experiments, and a way to perturb protein stability without affecting the chaperonin system itself. Here, by establishing such conditions, we show that protein stability in the chaperonin cage is reduced dramatically by more than 5 kcal mol-1 compared to that in bulk solution. Given that steric confinement alone is stabilizing, our results indicate that hydrophobic and/or electrostatic effects in the cavity are strongly destabilizing. Our findings are consistent with the iterative annealing mechanism of action proposed for the chaperonin GroEL.
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Affiliation(s)
- Ilia Korobko
- Departments of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Hisham Mazal
- Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Gilad Haran
- Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Amnon Horovitz
- Departments of Structural Biology, Weizmann Institute of Science, Rehovot, Israel
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14
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Balchin D, Hayer-Hartl M, Hartl FU. Recent advances in understanding catalysis of protein folding by molecular chaperones. FEBS Lett 2020; 594:2770-2781. [PMID: 32446288 DOI: 10.1002/1873-3468.13844] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/17/2020] [Accepted: 05/18/2020] [Indexed: 12/27/2022]
Abstract
Molecular chaperones are highly conserved proteins that promote proper folding of other proteins in vivo. Diverse chaperone systems assist de novo protein folding and trafficking, the assembly of oligomeric complexes, and recovery from stress-induced unfolding. A fundamental function of molecular chaperones is to inhibit unproductive protein interactions by recognizing and protecting hydrophobic surfaces that are exposed during folding or following proteotoxic stress. Beyond this basic principle, it is now clear that chaperones can also actively and specifically accelerate folding reactions in an ATP-dependent manner. We focus on the bacterial Hsp70 and chaperonin systems as paradigms, and review recent work that has advanced our understanding of how these chaperones act as catalysts of protein folding.
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Affiliation(s)
- David Balchin
- Protein Biogenesis Laboratory, The Francis Crick Institute, London, UK
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
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15
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Abstract
This chronologue seeks to document the discovery and development of an understanding of oligomeric ring protein assemblies known as chaperonins that assist protein folding in the cell. It provides detail regarding genetic, physiologic, biochemical, and biophysical studies of these ATP-utilizing machines from both in vivo and in vitro observations. The chronologue is organized into various topics of physiology and mechanism, for each of which a chronologic order is generally followed. The text is liberally illustrated to provide firsthand inspection of the key pieces of experimental data that propelled this field. Because of the length and depth of this piece, the use of the outline as a guide for selected reading is encouraged, but it should also be of help in pursuing the text in direct order.
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16
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Ntountoumi C, Vlastaridis P, Mossialos D, Stathopoulos C, Iliopoulos I, Promponas V, Oliver SG, Amoutzias GD. Low complexity regions in the proteins of prokaryotes perform important functional roles and are highly conserved. Nucleic Acids Res 2019; 47:9998-10009. [PMID: 31504783 PMCID: PMC6821194 DOI: 10.1093/nar/gkz730] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 07/16/2019] [Accepted: 08/15/2019] [Indexed: 01/27/2023] Open
Abstract
We provide the first high-throughput analysis of the properties and functional role of Low Complexity Regions (LCRs) in more than 1500 prokaryotic and phage proteomes. We observe that, contrary to a widespread belief based on older and sparse data, LCRs actually have a significant, persistent and highly conserved presence and role in many and diverse prokaryotes. Their specific amino acid content is linked to proteins with certain molecular functions, such as the binding of RNA, DNA, metal-ions and polysaccharides. In addition, LCRs have been repeatedly identified in very ancient, and usually highly expressed proteins of the translation machinery. At last, based on the amino acid content enriched in certain categories, we have developed a neural network web server to identify LCRs and accurately predict whether they can bind nucleic acids, metal-ions or are involved in chaperone functions. An evaluation of the tool showed that it is highly accurate for eukaryotic proteins as well.
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Affiliation(s)
- Chrysa Ntountoumi
- Bioinformatics Laboratory, Department of Biochemistry and Biotechnology, University of Thessaly, 41500, Greece
| | - Panayotis Vlastaridis
- Bioinformatics Laboratory, Department of Biochemistry and Biotechnology, University of Thessaly, 41500, Greece
| | - Dimitris Mossialos
- Microbial Biotechnology-Molecular Bacteriology-Virology Laboratory, Department of Biochemistry and Biotechnology, University of Thessaly, 41500, Greece
| | | | | | - Vasilios Promponas
- Bioinformatics Research Laboratory, Department of Biological Sciences, New Campus, University of Cyprus, PO Box 20537, CY-1678 Nicosia, Cyprus
| | - Stephen G Oliver
- Cambridge Systems Biology Centre & Department of Biochemistry, University of Cambridge, CB2 1GA, UK
| | - Grigoris D Amoutzias
- Bioinformatics Laboratory, Department of Biochemistry and Biotechnology, University of Thessaly, 41500, Greece
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17
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Structural and functional analysis of the role of the chaperonin CCT in mTOR complex assembly. Nat Commun 2019; 10:2865. [PMID: 31253771 PMCID: PMC6599039 DOI: 10.1038/s41467-019-10781-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 06/01/2019] [Indexed: 01/01/2023] Open
Abstract
The mechanistic target of rapamycin (mTOR) kinase forms two multi-protein signaling complexes, mTORC1 and mTORC2, which are master regulators of cell growth, metabolism, survival and autophagy. Two of the subunits of these complexes are mLST8 and Raptor, β-propeller proteins that stabilize the mTOR kinase and recruit substrates, respectively. Here we report that the eukaryotic chaperonin CCT plays a key role in mTORC assembly and signaling by folding both mLST8 and Raptor. A high resolution (4.0 Å) cryo-EM structure of the human mLST8-CCT intermediate isolated directly from cells shows mLST8 in a near-native state bound to CCT deep within the folding chamber between the two CCT rings, and interacting mainly with the disordered N- and C-termini of specific CCT subunits of both rings. These findings describe a unique function of CCT in mTORC assembly and a distinct binding site in CCT for mLST8, far from those found for similar β-propeller proteins. β-propeller domains are an important class of folding substrates for the eukaryotic cytosolic chaperonin CTT. Here the authors find that CTT contributes to the folding and assembly of two β-propeller proteins from mTOR complexes, mLST8 and Raptor, and determine the 4.0 Å cryoEM structure of a human mLST8-CCT intermediate that shows mLST8 in a near-native state.
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18
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Dahiya V, Buchner J. Functional principles and regulation of molecular chaperones. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2018; 114:1-60. [PMID: 30635079 DOI: 10.1016/bs.apcsb.2018.10.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
To be able to perform their biological function, a protein needs to be correctly folded into its three dimensional structure. The protein folding process is spontaneous and does not require the input of energy. However, in the crowded cellular environment where there is high risk of inter-molecular interactions that may lead to protein molecules sticking to each other, hence forming aggregates, protein folding is assisted. Cells have evolved robust machinery called molecular chaperones to deal with the protein folding problem and to maintain proteins in their functional state. Molecular chaperones promote efficient folding of newly synthesized proteins, prevent their aggregation and ensure protein homeostasis in cells. There are different classes of molecular chaperones functioning in a complex interplay. In this review, we discuss the principal characteristics of different classes of molecular chaperones, their structure-function relationships, their mode of regulation and their involvement in human disorders.
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Affiliation(s)
- Vinay Dahiya
- Center for Integrated Protein Science Munich CIPSM at the Department Chemie, Technische Universität München, Garching, Germany
| | - Johannes Buchner
- Center for Integrated Protein Science Munich CIPSM at the Department Chemie, Technische Universität München, Garching, Germany.
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19
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Motojima F, Fujii K, Yoshida M. Chaperonin facilitates protein folding by avoiding initial polypeptide collapse. J Biochem 2018; 164:369-379. [PMID: 30053017 PMCID: PMC6190516 DOI: 10.1093/jb/mvy061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Accepted: 07/12/2018] [Indexed: 11/14/2022] Open
Abstract
Chaperonins assist folding of many cellular proteins, including essential proteins for cell viability. However, it remains unclear how chaperonin-assisted folding is different from spontaneous folding. Chaperonin GroEL/GroES facilitates folding of denatured protein encapsulated in its central cage but the denatured protein often escapes from the cage to the outside during reaction. Here, we show evidence that the in-cage-folding and the escape occur diverging from the same intermediate complex in which polypeptide is tethered loosely to the cage and partly protrudes out of the cage. Furthermore, denatured proteins in the chaperonin cage are kept in more extended conformation than those initially formed in spontaneous folding. We propose that the formation of tethered intermediate of polypeptide is necessary to prevent polypeptide collapse at the expense of polypeptide escape. The tethering of polypeptide would allow freely mobile portions of tethered polypeptide to fold segmentally.
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Affiliation(s)
- Fumihiro Motojima
- Department of Molecular Biosciences, Kyoto Sangyo University Kamigamo-Motoyama, Kita-ku, Kyoto, Japan
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama, Japan
| | - Katsuya Fujii
- Department of Molecular Biosciences, Kyoto Sangyo University Kamigamo-Motoyama, Kita-ku, Kyoto, Japan
| | - Masasuke Yoshida
- Institute for Protein Dynamics, Kyoto Sangyo University, Kamigamo-Motoyama, Kita-ku, Kyoto, Japan
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20
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Piana S, Shaw DE. Atomic-Level Description of Protein Folding inside the GroEL Cavity. J Phys Chem B 2018; 122:11440-11449. [PMID: 30277396 DOI: 10.1021/acs.jpcb.8b07366] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chaperonins (ubiquitous facilitators of protein folding) sequester misfolded proteins within an internal cavity, thus preventing protein aggregation during the process of refolding. GroEL, a tetradecameric bacterial chaperonin, is one of the most studied chaperonins, but the role of the internal cavity in the refolding process is still unclear. It has been suggested that rather than simply isolating proteins while they refold, the GroEL cavity actively promotes protein folding. A detailed characterization of the folding dynamics and thermodynamics of protein substrates encapsulated within the cavity, however, has been difficult to obtain by experimental means, due to the system's complexity and the many steps in the folding cycle. Here, we examine the influence of the GroEL cavity on protein folding based on the results of unbiased, atomistic molecular dynamics simulations. We first verified that the computational setup, which uses a recently developed state-of-the-art force field that more accurately reproduces the aggregation propensity of unfolded states, could recapitulate the essential structural dynamics of GroEL. In these simulations, the GroEL tetradecamer was highly dynamic, transitioning among states corresponding to most of the structures that have been observed experimentally. We then simulated a small, unfolded protein both in the GroEL cavity and in bulk solution and compared the protein's folding process within these two environments. Inside the GroEL cavity, the unfolded protein interacted strongly with the disordered residues in GroEL's C-terminal tails. These interactions stabilized the protein's unfolded states relative to its compact states and increased the roughness of its folding free-energy surface, resulting in slower folding compared to the rate in solution. For larger proteins, which are more typical GroEL substrates, we speculate that these interactions may allow substrates to more quickly escape kinetic traps associated with compact, misfolded states, thereby actively promoting folding.
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Affiliation(s)
- Stefano Piana
- D. E. Shaw Research , New York , New York 10036 , United States
| | - David E Shaw
- D. E. Shaw Research , New York , New York 10036 , United States.,Department of Biochemistry and Molecular Biophysics , Columbia University , New York , New York 10032 , United States
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21
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Wälti MA, Libich DS, Clore GM. Extensive Sampling of the Cavity of the GroEL Nanomachine by Protein Substrates Probed by Paramagnetic Relaxation Enhancement. J Phys Chem Lett 2018; 9:3368-3371. [PMID: 29869885 PMCID: PMC6029692 DOI: 10.1021/acs.jpclett.8b01586] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The chaperonin GroEL is a 800 kDa nanomachine comprising two heptameric rings, each of which encloses a large cavity or folding chamber. The GroEL cycle involves ATP-dependent capping of the cavity by the cochaperone GroES to create a nanocage in which a single protein molecule can fold. We investigate how protein substrates sample the cavity prior to encapsulation by GroES using paramagnetic relaxation enhancement to detect transient, sparsely populated interactions between apo GroEL, paramagnetically labeled at several sites within the cavity, and three variants of an SH3 protein domain (the fully native wild type, a triple mutant that exchanges between a folded state and an excited folding intermediate, and a stable folding intermediate mimetic). We show that the substrate not only interacts with the hydrophobic inner rim of GroEL at the mouth of the cavity but also penetrates deep within the cavity, transiently contacting the disordered C-terminal tail, and, in the case of the folding intermediate mimetic, the base as well. Transient interactions with the C-terminal tail may facilitate substrate capture and retention prior to encapsulation.
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22
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Wang X, Chen H, Lu X, Chi H, Li S, Huang F. Probing the interaction mechanisms between transmembrane peptides and the chaperonin GroEL with fluorescence anisotropy. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018; 194:1-7. [PMID: 29304433 DOI: 10.1016/j.saa.2017.12.071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 12/23/2017] [Accepted: 12/28/2017] [Indexed: 06/07/2023]
Abstract
Proper translocation, membrane insertion and folding are crucial biophysical steps in the biogenesis of functional transmembrane peptides/proteins (TMPs). ATP-dependent chaperonins are able to regulate each of these processes, but the underlying mechanisms remain unclear. In this work, interaction between the bacterial chaperonin GroEL and a synthetic fluorescent transmembrane peptide was investigated by fluorescence anisotropy. Binding of the peptide with GroEL resulted in increased fluorescence anisotropy and intensity. The dissociation constant and binding stoichiometry, as assessed by titration of the peptide with GroEL, were estimated to be 0.6±0.2μM and 2.96±0.35, respectively. Complementary study with the single-ring version of GroEL confirmed the high-affinity peptide binding, and indicates that the two GroEL rings may function alternatively in binding the peptides. The co-chaperonin GroES was found to be effective at releasing the peptides initially bound to GroEL with the help of ATP. Moreover, our observation with the single-ring GroEL mutant demonstrated that during the encapsulation of GroEL by GroES, the bound peptides may either be confined in the cage thus formed, or escape outside. Competitive binding experiments indicated that the peptides studied interact with GroEL through the paired helices H and I on its apical domain. Our spectroscopic studies revealed some basic mechanisms of interaction between transmembrane peptides and GroEL, which would be instrumental for deciphering the chaperonin-mediated TMP biogenesis.
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Affiliation(s)
- Xiaoqiang Wang
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Han Chen
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Xinwei Lu
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Haixia Chi
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Shixin Li
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, PR China
| | - Fang Huang
- State Key Laboratory of Heavy Oil Processing and Center for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266580, PR China.
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23
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Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), a ∼530 kDa complex of 8 large (RbcL) and 8 small subunits (RbcS), mediates the fixation of atmospheric CO2 into usable sugars during photosynthesis. Despite its fundamental role, Rubisco is a remarkably inefficient enzyme and thus is produced by plants in huge amounts. It has long been a key target for bioengineering with the goal to increase crop yields. However, such efforts have been hampered by the complex requirement of Rubisco biogenesis for molecular chaperones. Recent studies have identified an array of auxiliary factors needed for the folding and assembly of the Rubisco subunits. The folding of plant RbcL subunits is mediated by the cylindrical chloroplast chaperonin, Cpn60, and its cofactor Cpn20. Folded RbcL requires a number of additional Rubisco specific assembly chaperones, including RbcX, Rubisco accumulation factors 1 (Raf1) and 2 (Raf2), and the Bundle sheath defective-2 (BSD2), to mediate the assembly of the RbcL8 intermediate complex. Incorporation of the RbcS and displacement of the assembly factors generates the active holoenzyme. An Escherichia coli strain expressing the chloroplast chaperonin and auxiliary factors now allows the expression of functional plant Rubisco, paving the way for Rubisco engineering by large scale mutagenesis. Here, we review our current understanding on how these chaperones cooperate to produce one of the most important enzymes in nature.
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Affiliation(s)
- Robert H Wilson
- Department of Cellular Biochemistry , Max Planck Institute of Biochemistry , Am Klopferspitz 18 , 82152 Martinsried , Germany
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry , Max Planck Institute of Biochemistry , Am Klopferspitz 18 , 82152 Martinsried , Germany
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24
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Abstract
The GroEL/ES chaperonin is known to prevent protein aggregation during folding by passive containment within the central cavity. The possible role of more active intervention is controversial. The HX MS method documents an organized hydrophobically stabilized folding preintermediate in the collapsed ensemble of maltose binding protein. A mutational defect destabilizes the preintermediate and greatly slows folding of the subsequent on-pathway H-bonded intermediate. GroEL encapsulation alone, without ATP and substrate protein cycling, restabilizes the preintermediate and restores fast folding. The mechanism appears to depend on forceful compression during confinement. More generally, these results suggest that GroEL can repair different folding defects in different ways. We used hydrogen exchange–mass spectrometry (HX MS) and fluorescence to compare the folding of maltose binding protein (MBP) in free solution and in the GroEL/ES cavity. Upon refolding, MBP initially collapses into a dynamic molten globule-like ensemble, then forms an obligatory on-pathway native-like folding intermediate (1.2 seconds) that brings together sequentially remote segments and then folds globally after a long delay (30 seconds). A single valine to glycine mutation imposes a definable folding defect, slows early intermediate formation by 20-fold, and therefore subsequent global folding by approximately twofold. Simple encapsulation within GroEL repairs the folding defect and reestablishes fast folding, with or without ATP-driven cycling. Further examination exposes the structural mechanism. The early folding intermediate is stabilized by an organized cluster of 24 hydrophobic side chains. The cluster preexists in the collapsed ensemble before the H-bond formation seen by HX MS. The V9G mutation slows folding by disrupting the preintermediate cluster. GroEL restores wild-type folding rates by restabilizing the preintermediate, perhaps by a nonspecific equilibrium compression effect within its tightly confining central cavity. These results reveal an active GroEL function other than previously proposed mechanisms, suggesting that GroEL possesses different functionalities that are able to relieve different folding problems. The discovery of the preintermediate, its mutational destabilization, and its restoration by GroEL encapsulation was made possible by the measurement of a previously unexpected type of low-level HX protection, apparently not dependent on H-bonding, that may be characteristic of proteins in confined spaces.
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25
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Okamoto T, Yamamoto H, Kudo I, Matsumoto K, Odaka M, Grave E, Itoh H. HSP60 possesses a GTPase activity and mediates protein folding with HSP10. Sci Rep 2017; 7:16931. [PMID: 29208924 PMCID: PMC5717063 DOI: 10.1038/s41598-017-17167-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 11/22/2017] [Indexed: 12/05/2022] Open
Abstract
The mammalian molecular chaperone, HSP60, plays an essential role in protein homeostasis through mediating protein folding and assembly. The structure and ATP-dependent function of HSP60 has been well established in recent studies. After ATP, GTP is the major cellular nucleotide. In this paper, we have investigated the role of GTP in the activity of HSP60. It was found that HSP60 has different properties with respect to allostery, complex formation and protein folding activity depending on the nucleoside triphosphate present. The presence of GTP slightly affected the ATPase activity of HSP60 during protein folding. These results provide clues as to the functional mechanism of the HSP60-HSP10 complex.
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Affiliation(s)
- Tomoya Okamoto
- Department of Life Science, Graduate School and Faculty of Engineering Science, Akita University, Akita, 010-8502, Japan
| | - Hiroshi Yamamoto
- Department of Life Science, Graduate School and Faculty of Engineering Science, Akita University, Akita, 010-8502, Japan
| | - Ikuru Kudo
- Department of Life Science, Graduate School and Faculty of Engineering Science, Akita University, Akita, 010-8502, Japan
| | - Kazuya Matsumoto
- Department of Applied Chemistry, Graduate School and Faculty of Engineering Science, Akita University, Akita, 010-8502, Japan
| | - Masafumi Odaka
- Department of Life Science, Graduate School and Faculty of Engineering Science, Akita University, Akita, 010-8502, Japan
| | - Ewa Grave
- Department of Life Science, Graduate School and Faculty of Engineering Science, Akita University, Akita, 010-8502, Japan
| | - Hideaki Itoh
- Department of Life Science, Graduate School and Faculty of Engineering Science, Akita University, Akita, 010-8502, Japan.
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26
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Hayer-Hartl M. From chaperonins to Rubisco assembly and metabolic repair. Protein Sci 2017; 26:2324-2333. [PMID: 28960553 DOI: 10.1002/pro.3309] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 09/21/2017] [Accepted: 09/25/2017] [Indexed: 01/13/2023]
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) mediates the fixation of atmospheric CO2 in photosynthesis by catalyzing the carboxylation of the 5-carbon sugar ribulose-1,5-bisphosphate (RuBP). Despite its pivotal role, Rubisco is an inefficient enzyme and thus has been a key target for bioengineering. However, efforts to increase crop yields by Rubisco engineering remain unsuccessful, due in part to the complex machinery of molecular chaperones required for Rubisco biogenesis and metabolic repair. While the large subunit of Rubisco generally requires the chaperonin system for folding, the evolution of the hexadecameric Rubisco from its dimeric precursor resulted in the dependence on an array of additional factors required for assembly. Moreover, Rubisco function can be inhibited by a range of sugar-phosphate ligands. Metabolic repair of Rubisco depends on remodeling by the ATP-dependent Rubisco activase and hydrolysis of inhibitors by specific phosphatases. This review highlights our work toward understanding the structure and mechanism of these auxiliary machineries.
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Affiliation(s)
- Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
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27
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Wälti MA, Clore GM. Disassembly/reassembly strategy for the production of highly pure GroEL, a tetradecameric supramolecular machine, suitable for quantitative NMR, EPR and mutational studies. Protein Expr Purif 2017; 142:8-15. [PMID: 28951283 DOI: 10.1016/j.pep.2017.09.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/20/2017] [Accepted: 09/20/2017] [Indexed: 11/20/2022]
Abstract
GroEL, a prototypical member of the chaperonin class of chaperones, is a large supramocular machine that assists protein folding and plays an important role in proteostasis. GroEL comprises two heptameric rings, each of which encloses a large cavity that provides a folding chamber for protein substrates. Many questions remain regarding the mechanistic details of GroEL facilitated protein folding. Thus, data at atomic resolution of the type provided by NMR and EPR are invaluable. Such studies often require complete deuteration of GroEL, uniform or residue specific 13C and 15N isotope labeling, and the introduction of selective cysteine mutations for site-specific spin labeling. In addition, high purity GroEL is essential for detailed studies of substrate-GroEL interactions as quantitative interpretation is impossible if the cavities are already occupied and blocked by other protein substrates present in the bacterial expression system. Here we present a new purification protocol designed to provide highly pure GroEL devoid of non-specific protein substrate contamination.
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Affiliation(s)
- Marielle A Wälti
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, United States
| | - G Marius Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, United States.
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28
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Weaver J, Jiang M, Roth A, Puchalla J, Zhang J, Rye HS. GroEL actively stimulates folding of the endogenous substrate protein PepQ. Nat Commun 2017; 8:15934. [PMID: 28665408 PMCID: PMC5497066 DOI: 10.1038/ncomms15934] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Accepted: 05/13/2017] [Indexed: 12/29/2022] Open
Abstract
Many essential proteins cannot fold without help from chaperonins, like the GroELS system of Escherichia coli. How chaperonins accelerate protein folding remains controversial. Here we test key predictions of both passive and active models of GroELS-stimulated folding, using the endogenous E. coli metalloprotease PepQ. While GroELS increases the folding rate of PepQ by over 15-fold, we demonstrate that slow spontaneous folding of PepQ is not caused by aggregation. Fluorescence measurements suggest that, when folding inside the GroEL-GroES cavity, PepQ populates conformations not observed during spontaneous folding in free solution. Using cryo-electron microscopy, we show that the GroEL C-termini make physical contact with the PepQ folding intermediate and help retain it deep within the GroEL cavity, resulting in reduced compactness of the PepQ monomer. Our findings strongly support an active model of chaperonin-mediated protein folding, where partial unfolding of misfolded intermediates plays a key role. In the prevailing model for assisted protein folding, chaperonins act passively by preventing protein aggregation. Here, the authors use single-molecule fluorescence measurements and cryo-electron microscopy and show that the E. coli GroELS chaperonin system also has an active role in folding the endogenous bacterial protein PepQ.
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Affiliation(s)
- Jeremy Weaver
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77845, USA
| | - Mengqiu Jiang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77845, USA.,State Key Laboratory of Biocontrol, School of Life Science, Sun Yat-sen University, Guangzhou, Guangdong 510275, China
| | - Andrew Roth
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77845, USA
| | - Jason Puchalla
- Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Junjie Zhang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77845, USA
| | - Hays S Rye
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77845, USA
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29
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Koldewey P, Horowitz S, Bardwell JCA. Chaperone-client interactions: Non-specificity engenders multifunctionality. J Biol Chem 2017; 292:12010-12017. [PMID: 28620048 DOI: 10.1074/jbc.r117.796862] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Here, we provide an overview of the different mechanisms whereby three different chaperones, Spy, Hsp70, and Hsp60, interact with folding proteins, and we discuss how these chaperones may guide the folding process. Available evidence suggests that even a single chaperone can use many mechanisms to aid in protein folding, most likely due to the need for most chaperones to bind clients promiscuously. Chaperone mechanism may be better understood by always considering it in the context of the client's folding pathway and biological function.
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Affiliation(s)
- Philipp Koldewey
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109
| | - Scott Horowitz
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109
| | - James C A Bardwell
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109; Howard Hughes Medical Institute, University of Michigan, Ann Arbor, Michigan 48109.
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30
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Pancsa R, Tompa P. Essential functions linked with structural disorder in organisms of minimal genome. Biol Direct 2016; 11:45. [PMID: 27608806 PMCID: PMC5016991 DOI: 10.1186/s13062-016-0149-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 09/03/2016] [Indexed: 12/13/2022] Open
Abstract
Abstract Intrinsically disordered regions (IDRs) of proteins fulfill important regulatory roles in most organisms. However, the proteins of certain endosymbiont and intracellular pathogenic bacteria with extremely reduced genomes contain disproportionately small amounts of IDRs, consisting almost entirely of folded domains. As their genomes co-evolving with their hosts have been reduced in unrelated lineages, the proteomes of these bacteria represent independently evolved minimal protein sets. We systematically analyzed structural disorder in a representative set of such minimal organisms to see which types of functionally relevant longer IDRs are invariably retained in them. We found that a few characteristic functions are consistently linked with conformational disorder: ribosomal proteins, key components of the protein production machinery, a central coordinator of DNA metabolism and certain housekeeping chaperones seem to strictly rely on structural disorder even in genome-reduced organisms. We propose that these functions correspond to the most essential and probably also the most ancient ones fulfilled by structural disorder in cellular organisms. Reviewers This article was reviewed by Michael Gromiha, Zoltan Gaspari and Sandor Pongor. Electronic supplementary material The online version of this article (doi:10.1186/s13062-016-0149-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rita Pancsa
- Structural Biology Research Center (SBRC), Flanders Institute for Biotechnology (VIB), Vrije Universiteit Brussel (VUB), 1050 Pleinlaan 2, Brussels, Belgium
| | - Peter Tompa
- Structural Biology Research Center (SBRC), Flanders Institute for Biotechnology (VIB), Vrije Universiteit Brussel (VUB), 1050 Pleinlaan 2, Brussels, Belgium. .,Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1117 Budapest, Magyar Tudósok körútja 2., Budapest, Hungary.
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31
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Balchin D, Hayer-Hartl M, Hartl FU. In vivo aspects of protein folding and quality control. Science 2016; 353:aac4354. [DOI: 10.1126/science.aac4354] [Citation(s) in RCA: 832] [Impact Index Per Article: 104.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Most proteins must fold into unique three-dimensional structures to perform their biological functions. In the crowded cellular environment, newly synthesized proteins are at risk of misfolding and forming toxic aggregate species. To ensure efficient folding, different classes of molecular chaperones receive the nascent protein chain emerging from the ribosome and guide it along a productive folding pathway. Because proteins are structurally dynamic, constant surveillance of the proteome by an integrated network of chaperones and protein degradation machineries is required to maintain protein homeostasis (proteostasis). The capacity of this proteostasis network declines during aging, facilitating neurodegeneration and other chronic diseases associated with protein aggregation. Understanding the proteostasis network holds the promise of identifying targets for pharmacological intervention in these pathologies.
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Abstract
Chaperonins are nanomachines that facilitate protein folding by undergoing energy (ATP)-dependent movements that are coordinated in time and space owing to complex allosteric regulation. They consist of two back-to-back stacked oligomeric rings with a cavity at each end where protein substrate folding can take place. Here, we focus on the GroEL/GroES chaperonin system from Escherichia coli and, to a lesser extent, on the more poorly characterized eukaryotic chaperonin CCT/TRiC. We describe their various functional (allosteric) states and how they are affected by substrates and allosteric effectors that include ATP, ADP, nonfolded protein substrates, potassium ions, and GroES (in the case of GroEL). We also discuss the pathways of intra- and inter-ring allosteric communication by which they interconvert and the coupling between allosteric transitions and protein folding reactions.
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Affiliation(s)
- Ranit Gruber
- Department of Structural Biology, Weizmann Institute of Science , Rehovot 76100, Israel
| | - Amnon Horovitz
- Department of Structural Biology, Weizmann Institute of Science , Rehovot 76100, Israel
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Okamoto T, Ishida R, Yamamoto H, Tanabe-Ishida M, Haga A, Takahashi H, Takahashi K, Goto D, Grave E, Itoh H. Functional structure and physiological functions of mammalian wild-type HSP60. Arch Biochem Biophys 2015; 586:10-9. [PMID: 26427351 DOI: 10.1016/j.abb.2015.09.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 09/20/2015] [Accepted: 09/25/2015] [Indexed: 11/16/2022]
Abstract
The Chaperonins comprise a family of molecular chaperones having a double-ring structure and similar sequence homology. These proteins play an essential role in biological reactions that mediate the folding of newly synthesized polypeptides and partially denatured proteins. In the prokaryotic group I chaperonins, structural and reaction cycle analyses of GroEL and its co-chaperone GroES have been performed in detail. While in eukaryotes, there have been limited reports analyzing the group I chaperonin HSP60 and its co-chaperone HSP10. In the present study, we purified the wild type HSP60 from porcine liver and investigated the interaction between HSP60 and HSP10, including conformation and physiological relationships. Based on the results of transmission electron microscopy, native PAGE, and gel filtration column chromatography, the wild type HSP60 displayed a heptameric single-ring structure in the absence of ATP. In contrast, HSP60 formed mainly a "football-type" complex with HSP10 in the presence of ATP and mediated the refolding of denatured substrate protein. The functional conformation cycle of the purified mammalian HSP60 is distinct from the cycle of the prokaryotic GroEL/GroES chaperonin.
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Affiliation(s)
- Tomoya Okamoto
- Department of Life Science, Graduate School and Faculty of Engineering Science, Akita University, Akita 010-8502, Japan
| | - Ryuichi Ishida
- Department of Life Science, Graduate School and Faculty of Engineering Science, Akita University, Akita 010-8502, Japan; Department of Biomolecular Science and Engineering, The Institute of Scientific and Industrial Research, Osaka University, 1-1 Yamadagaoka Suita, Osaka 565-0871, Japan
| | - Hiroshi Yamamoto
- Department of Life Science, Graduate School and Faculty of Engineering Science, Akita University, Akita 010-8502, Japan
| | - Masako Tanabe-Ishida
- Department of Life Science, Graduate School and Faculty of Engineering Science, Akita University, Akita 010-8502, Japan
| | - Asami Haga
- Department of Life Science, Graduate School and Faculty of Engineering Science, Akita University, Akita 010-8502, Japan
| | - Hiroki Takahashi
- Department of Life Science, Graduate School and Faculty of Engineering Science, Akita University, Akita 010-8502, Japan
| | - Kyosuke Takahashi
- Department of Life Science, Graduate School and Faculty of Engineering Science, Akita University, Akita 010-8502, Japan
| | - Daisuke Goto
- Department of Life Science, Graduate School and Faculty of Engineering Science, Akita University, Akita 010-8502, Japan
| | - Ewa Grave
- Department of Life Science, Graduate School and Faculty of Engineering Science, Akita University, Akita 010-8502, Japan
| | - Hideaki Itoh
- Department of Life Science, Graduate School and Faculty of Engineering Science, Akita University, Akita 010-8502, Japan.
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The GroEL-GroES Chaperonin Machine: A Nano-Cage for Protein Folding. Trends Biochem Sci 2015; 41:62-76. [PMID: 26422689 DOI: 10.1016/j.tibs.2015.07.009] [Citation(s) in RCA: 242] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Revised: 07/21/2015] [Accepted: 07/31/2015] [Indexed: 01/12/2023]
Abstract
The bacterial chaperonin GroEL and its cofactor GroES constitute the paradigmatic molecular machine of protein folding. GroEL is a large double-ring cylinder with ATPase activity that binds non-native substrate protein (SP) via hydrophobic residues exposed towards the ring center. Binding of the lid-shaped GroES to GroEL displaces the bound protein into an enlarged chamber, allowing folding to occur unimpaired by aggregation. GroES and SP undergo cycles of binding and release, regulated allosterically by the GroEL ATPase. Recent structural and functional studies are providing insights into how the physical environment of the chaperonin cage actively promotes protein folding, in addition to preventing aggregation. Here, we review different models of chaperonin action and discuss issues of current debate.
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Tompa P, Schad E, Tantos A, Kalmar L. Intrinsically disordered proteins: emerging interaction specialists. Curr Opin Struct Biol 2015; 35:49-59. [PMID: 26402567 DOI: 10.1016/j.sbi.2015.08.009] [Citation(s) in RCA: 150] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 08/23/2015] [Accepted: 08/28/2015] [Indexed: 12/22/2022]
Abstract
Intrinsically disordered proteins or regions of proteins (IDPs/IDRs) most often function through protein-protein interactions, when they permanently or transiently bind partner molecules with diverse functional consequences. There is a rapid advance in our understanding of the ensuing functional modes, obtained from describing atomic details of individual complexes, proteome-wide studies of interactomes and characterizing loosely assembled hydrogels and tightly packed amyloids. Here we briefly survey the most important recent methodological developments and structural-functional observations, with the aim of increasing the general appreciation of IDPs/IDRs as 'interaction specialists'.
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Affiliation(s)
- Peter Tompa
- VIB Structural Biology Research Center (SBRC), Brussels, Belgium; Vrije Universiteit Brussel, Brussels, Belgium; Institute of Enzymology, Research Centre for Natural Sciences of the Hungarian Academy of Sciences, Budapest, Hungary.
| | - Eva Schad
- Institute of Enzymology, Research Centre for Natural Sciences of the Hungarian Academy of Sciences, Budapest, Hungary
| | - Agnes Tantos
- Institute of Enzymology, Research Centre for Natural Sciences of the Hungarian Academy of Sciences, Budapest, Hungary
| | - Lajos Kalmar
- Institute of Enzymology, Research Centre for Natural Sciences of the Hungarian Academy of Sciences, Budapest, Hungary
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Ishino S, Kawata Y, Taguchi H, Kajimura N, Matsuzaki K, Hoshino M. Effects of C-terminal Truncation of Chaperonin GroEL on the Yield of In-cage Folding of the Green Fluorescent Protein. J Biol Chem 2015; 290:15042-51. [PMID: 25887400 DOI: 10.1074/jbc.m114.633636] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Indexed: 11/06/2022] Open
Abstract
Chaperonin GroEL from Escherichia coli consists of two heptameric rings stacked back-to-back to form a cagelike structure. It assists in the folding of substrate proteins in concert with the co-chaperonin GroES by incorporating them into its large cavity. The mechanism underlying the incorporation of substrate proteins currently remains unclear. The flexible C-terminal residues of GroEL, which are invisible in the x-ray crystal structure, have recently been suggested to play a key role in the efficient encapsulation of substrates. These C-terminal regions have also been suggested to separate the double rings of GroEL at the bottom of the cavity. To elucidate the role of the C-terminal regions of GroEL on the efficient encapsulation of substrate proteins, we herein investigated the effects of C-terminal truncation on GroE-mediated folding using the green fluorescent protein (GFP) as a substrate. We demonstrated that the yield of in-cage folding mediated by a single ring GroEL (SR1) was markedly decreased by truncation, whereas that mediated by a double ring football-shaped complex was not affected. These results suggest that the C-terminal region of GroEL functions as a barrier between rings, preventing the leakage of GFP through the bottom space of the cage. We also found that once GFP folded into its native conformation within the cavity of SR1 it never escaped even in the absence of the C-terminal tails. This suggests that GFP molecules escaped through the pore only when they adopted a denatured conformation. Therefore, the folding and escape of GFP from C-terminally truncated SR1·GroES appeared to be competing with each other.
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Affiliation(s)
- So Ishino
- From the Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yasushi Kawata
- Department of Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama-Minami, Tottori 680-8552, Japan
| | - Hideki Taguchi
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, B-56, 4259 Nagatsuta, Midori-ku, Yokohama 226-8501, Japan, and
| | - Naoko Kajimura
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Katsumi Matsuzaki
- From the Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi, Sakyo-ku, Kyoto 606-8501, Japan
| | - Masaru Hoshino
- From the Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Yoshida-Shimoadachi, Sakyo-ku, Kyoto 606-8501, Japan,
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37
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Abstract
Protein folding is a biological process that is essential for the proper functioning of proteins in all living organisms. In cells, many proteins require the assistance of molecular chaperones for their folding. Chaperonins belong to a class of molecular chaperones that have been extensively studied. However, the mechanism by which a chaperonin mediates the folding of proteins is still controversial. Denatured proteins are folded in the closed chaperonin cage, leading to the assumption that denatured proteins are completely encapsulated inside the chaperonin cage. In contrast to the assumption, we recently found that denatured protein interacts with hydrophobic residues at the subunit interfaces of the chaperonin, and partially protrude out of the cage. In this review, we will explain our recent results and introduce our model for the mechanism by which chaperonins accelerate protein folding, in view of recent findings.
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Affiliation(s)
- Fumihiro Motojima
- Department of Molecular Biosciences, Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kita-ku, Kyoto 603-8555, Japan
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Dalton KM, Frydman J, Pande VS. The dynamic conformational cycle of the group I chaperonin C-termini revealed via molecular dynamics simulation. PLoS One 2015; 10:e0117724. [PMID: 25822285 PMCID: PMC4379175 DOI: 10.1371/journal.pone.0117724] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 12/31/2014] [Indexed: 11/24/2022] Open
Abstract
Chaperonins are large ring shaped oligomers that facilitate protein folding by encapsulation within a central cavity. All chaperonins possess flexible C-termini which protrude from the equatorial domain of each subunit into the central cavity. Biochemical evidence suggests that the termini play an important role in the allosteric regulation of the ATPase cycle, in substrate folding and in complex assembly and stability. Despite the tremendous wealth of structural data available for numerous orthologous chaperonins, little structural information is available regarding the residues within the C-terminus. Herein, molecular dynamics simulations are presented which localize the termini throughout the nucleotide cycle of the group I chaperonin, GroE, from Escherichia coli. The simulation results predict that the termini undergo a heretofore unappreciated conformational cycle which is coupled to the nucleotide state of the enzyme. As such, these results have profound implications for the mechanism by which GroE utilizes nucleotide and folds client proteins.
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Affiliation(s)
- Kevin M. Dalton
- Biophysics Program, Stanford University, Stanford, California, United States of America
| | - Judith Frydman
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Vijay S. Pande
- Department of Chemistry, Stanford University, Stanford, California, United States of America
- * E-mail:
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Bhandari V, Houry WA. Substrate Interaction Networks of the Escherichia coli Chaperones: Trigger Factor, DnaK and GroEL. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 883:271-94. [PMID: 26621473 DOI: 10.1007/978-3-319-23603-2_15] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In the dense cellular environment, protein misfolding and inter-molecular protein aggregation compete with protein folding. Chaperones associate with proteins to prevent misfolding and to assist in folding to the native state. In Escherichia coli, the chaperones trigger factor, DnaK/DnaJ/GrpE, and GroEL/ES are the major chaperones responsible for insuring proper de novo protein folding. With multitudes of proteins produced by the bacterium, the chaperones have to be selective for their substrates. Yet, chaperone selectivity cannot be too specific. Recent biochemical and high-throughput studies have provided important insights highlighting the strategies used by chaperones in maintaining proteostasis in the cell. Here, we discuss the substrate networks and cooperation among these protein folding chaperones.
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Affiliation(s)
- Vaibhav Bhandari
- Department of Biochemistry, University of Toronto, 1 King's College Circle, Medical Sciences Building, Room 5308, Toronto, ON, M5S 1A8, Canada
| | - Walid A Houry
- Department of Biochemistry, University of Toronto, 1 King's College Circle, Medical Sciences Building, Room 5308, Toronto, ON, M5S 1A8, Canada.
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Affiliation(s)
- Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; and
| | - Patricia L Clark
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana, USA
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