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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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Abella JR, Moll M, Kavraki LE. Maintaining and Enhancing Diversity of Sampled Protein Conformations in Robotics-Inspired Methods. J Comput Biol 2018; 25:3-20. [PMID: 29035572 PMCID: PMC5756939 DOI: 10.1089/cmb.2017.0164] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The ability to efficiently sample structurally diverse protein conformations allows one to gain a high-level view of a protein's energy landscape. Algorithms from robot motion planning have been used for conformational sampling, and several of these algorithms promote diversity by keeping track of "coverage" in conformational space based on the local sampling density. However, large proteins present special challenges. In particular, larger systems require running many concurrent instances of these algorithms, but these algorithms can quickly become memory intensive because they typically keep previously sampled conformations in memory to maintain coverage estimates. In addition, robotics-inspired algorithms depend on defining useful perturbation strategies for exploring the conformational space, which is a difficult task for large proteins because such systems are typically more constrained and exhibit complex motions. In this article, we introduce two methodologies for maintaining and enhancing diversity in robotics-inspired conformational sampling. The first method addresses algorithms based on coverage estimates and leverages the use of a low-dimensional projection to define a global coverage grid that maintains coverage across concurrent runs of sampling. The second method is an automatic definition of a perturbation strategy through readily available flexibility information derived from B-factors, secondary structure, and rigidity analysis. Our results show a significant increase in the diversity of the conformations sampled for proteins consisting of up to 500 residues when applied to a specific robotics-inspired algorithm for conformational sampling. The methodologies presented in this article may be vital components for the scalability of robotics-inspired approaches.
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Affiliation(s)
- Jayvee R Abella
- 1 Department of Computer Science, Rice University , Houston, Texas
| | - Mark Moll
- 1 Department of Computer Science, Rice University , Houston, Texas
| | - Lydia E Kavraki
- 1 Department of Computer Science, Rice University , Houston, Texas
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Skjærven L, Cuellar J, Martinez A, Valpuesta JM. Dynamics, flexibility, and allostery in molecular chaperonins. FEBS Lett 2015; 589:2522-32. [PMID: 26140986 DOI: 10.1016/j.febslet.2015.06.019] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Revised: 06/18/2015] [Accepted: 06/23/2015] [Indexed: 12/26/2022]
Abstract
The chaperonins are a family of molecular chaperones present in all three kingdoms of life. They are classified into Group I and Group II. Group I consists of the bacterial variants (GroEL) and the eukaryotic ones from mitochondria and chloroplasts (Hsp60), while Group II consists of the archaeal (thermosomes) and eukaryotic cytosolic variants (CCT or TRiC). Both groups assemble into a dual ring structure, with each ring providing a protective folding chamber for nascent and denatured proteins. Their functional cycle is powered by ATP binding and hydrolysis, which drives a series of structural rearrangements that enable encapsulation and subsequent release of the substrate protein. Chaperonins have elaborate allosteric mechanisms to regulate their functional cycle. Long-range negative cooperativity between the two rings ensures alternation of the folding chambers. Positive intra-ring cooperativity, which facilitates concerted conformational transitions within the protein subunits of one ring, has only been demonstrated for Group I chaperonins. In this review, we describe our present understanding of the underlying mechanisms and the structure-function relationships in these complex protein systems with a particular focus on the structural dynamics, allostery, and associated conformational rearrangements.
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Affiliation(s)
- Lars Skjærven
- Department of Biomedicine, University of Bergen, Bergen, Norway.
| | - Jorge Cuellar
- Department of Macromolecular Structure, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
| | - Aurora Martinez
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - José María Valpuesta
- Department of Macromolecular Structure, Centro Nacional de Biotecnología (CNB-CSIC), Madrid, Spain
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Abdel-Azeim S, Oliva R, Chermak E, De Cristofaro R, Cavallo L. Molecular Dynamics Characterization of Five Pathogenic Factor X Mutants Associated with Decreased Catalytic Activity. Biochemistry 2014; 53:6992-7001. [DOI: 10.1021/bi500770p] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Safwat Abdel-Azeim
- Kaust
Catalysis Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Romina Oliva
- Department
of Sciences and Technologies, University “Parthenope” of Naples, Centro Direzionale Isola C4, 80133 Naples, Italy
| | - Edrisse Chermak
- Kaust
Catalysis Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Raimondo De Cristofaro
- Hemostasis
Research Centre, Institute of Internal Medicine and Geriatrics, Catholic University School of Medicine, Rome, Italy
| | - Luigi Cavallo
- Kaust
Catalysis Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
- Dipartimento
di Chimica e Biologia, University of Salerno, Via Papa Giovanni Paolo II, I-84084 Fisciano, Italy
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Wang Y, Zhang WY, Zhang Z, Li J, Li ZF, Tan ZG, Zhang TT, Wu ZH, Liu H, Li YZ. Mechanisms involved in the functional divergence of duplicated GroEL chaperonins in Myxococcus xanthus DK1622. PLoS Genet 2013; 9:e1003306. [PMID: 23437010 PMCID: PMC3578752 DOI: 10.1371/journal.pgen.1003306] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 12/20/2012] [Indexed: 12/24/2022] Open
Abstract
The gene encoding the GroEL chaperonin is duplicated in nearly 30% of bacterial genomes; and although duplicated groEL genes have been comprehensively determined to have distinct physiological functions in different species, the mechanisms involved have not been characterized to date. Myxococcus xanthus DK1622 has two copies of the groEL gene, each of which can be deleted without affecting cell viability; however, the deletion of either gene does result in distinct defects in the cellular heat-shock response, predation, and development. In this study, we show that, from the expression levels of different groELs, the distinct functions of groEL1 and groEL2 in predation and development are probably the result of the substrate selectivity of the paralogous GroEL chaperonins, whereas the lethal effect of heat shock due to the deletion of groEL1 is caused by a decrease in the total groEL expression level. Following a bioinformatics analysis of the composition characteristics of GroELs from different bacteria, we performed region-swapping assays in M. xanthus, demonstrating that the differences in the apical and the C-terminal equatorial regions determine the substrate specificity of the two GroELs. Site-directed mutagenesis experiments indicated that the GGM repeat sequence at the C-terminus of GroEL1 plays an important role in functional divergence. Divergent functions of duplicated GroELs, which have similar patterns of variation in different bacterial species, have thus evolved mainly via alteration of the apical and the C-terminal equatorial regions. We identified the specific substrates of strain DK1622's GroEL1 and GroEL2 using immunoprecipitation and mass spectrometry techniques. Although 68 proteins bound to both GroEL1 and GroEL2, 83 and 46 proteins bound exclusively to GroEL1 or GroEL2, respectively. The GroEL-specific substrates exhibited distinct molecular sizes and secondary structures, providing an encouraging indication for GroEL evolution for functional divergence.
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Affiliation(s)
- Yan Wang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
| | - Wen-yan Zhang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
| | - Zheng Zhang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
| | - Jian Li
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
| | - Zhi-feng Li
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
| | - Zai-gao Tan
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
| | - Tian-tian Zhang
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
| | - Zhi-hong Wu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
| | - Hong Liu
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
| | - Yue-zhong Li
- State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, China
- * E-mail:
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