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Bulone D, San Biagio PL, Quiñones-Ruiz T, Rosario-Alomar M, Lednev IK, Robb FT, Conway de Macario E, Macario AJL. A Multipronged Method for Unveiling Subtle Structural-Functional Defects of Mutant Chaperone Molecules Causing Human Chaperonopathies. Methods Mol Biol 2019; 1873:69-92. [PMID: 30341604 DOI: 10.1007/978-1-4939-8820-4_5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Chaperonopathies are diseases in which abnormal chaperones play an etiopathogenic role. A chaperone is mutated or otherwise abnormal (e.g., modified by an aberrant posttranslational modification) in structure/function. To understand the pathogenic mechanisms of chaperonopathies, it is necessary to elucidate the impact of the pathogenic mutation or posttranslational modification on the chaperone molecule's properties and functions. This impact is usually subtle because if it were more than subtle the overall effect on the cell and organism would be catastrophic, lethal. This is because most chaperones are essential for life and, if damaged in structure/function too strongly, there would be death of the cell/organism, and no phenotype, i.e., there would be no patients with chaperonopathies. Consequently, diagnostic procedures and analysis of defects of the abnormal chaperones require a multipronged method for assessing the chaperone molecule from various angles. Here, we present such a method that includes assessing the intrinsic properties and the chaperoning functions of chaperone molecules.
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Affiliation(s)
- Donatella Bulone
- Institute of Biophysics, SL Palermo, National Research Council, Palermo, Italy
| | | | | | | | - Igor K Lednev
- Department of Chemistry, University at Albany, SUNY, Albany, NY, USA
| | - Frank T Robb
- Department of Microbiology and Immunology, School of Medicine, University of Maryland at Baltimore-Institute of Marine and Environmental Technology (IMET), Baltimore, MD, USA
- Institute for Bioscience and Biotechnology Research (IBBR), Rockville, MD, USA
| | - Everly Conway de Macario
- Department of Microbiology and Immunology, School of Medicine, University of Maryland at Baltimore-Institute of Marine and Environmental Technology (IMET), Baltimore, MD, USA
- Euro-Mediterranean Institute of Science and Technology (IEMEST), Palermo, Italy
| | - Alberto J L Macario
- Department of Microbiology and Immunology, School of Medicine, University of Maryland at Baltimore-Institute of Marine and Environmental Technology (IMET), Baltimore, MD, USA.
- Euro-Mediterranean Institute of Science and Technology (IEMEST), Palermo, Italy.
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2
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Biosynthesis of ω-hydroxy fatty acids and related chemicals from natural fatty acids by recombinant Escherichia coli. Appl Microbiol Biotechnol 2018; 103:191-199. [DOI: 10.1007/s00253-018-9503-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 11/01/2018] [Accepted: 11/05/2018] [Indexed: 10/27/2022]
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3
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An YJ, Rowland SE, Na JH, Spigolon D, Hong SK, Yoon YJ, Lee JH, Robb FT, Cha SS. Structural and mechanistic characterization of an archaeal-like chaperonin from a thermophilic bacterium. Nat Commun 2017; 8:827. [PMID: 29018216 PMCID: PMC5635000 DOI: 10.1038/s41467-017-00980-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 08/08/2017] [Indexed: 11/13/2022] Open
Abstract
The chaperonins (CPNs) are megadalton sized hollow complexes with two cavities that open and close to encapsulate non-native proteins. CPNs are assigned to two sequence-related groups that have distinct allosteric mechanisms. In Group I CPNs a detachable co-chaperone, GroES, closes the chambers whereas in Group II a built-in lid closes the chambers. Group I CPNs have a bacterial ancestry, whereas Group II CPNs are archaeal in origin. Here we describe open and closed crystal structures representing a new phylogenetic branch of CPNs. These Group III CPNs are divergent in sequence and structure from extant CPNs, but are closed by a built-in lid like Group II CPNs. A nucleotide-sensing loop, present in both Group I and Group II CPNs, is notably absent. We identified inter-ring pivot joints that articulate during ring closure. These Group III CPNs likely represent a relic from the ancestral CPN that formed distinct bacterial and archaeal branches. Chaperonins (CPNs) are ATP-dependent protein-folding machines. Here the authors present the open and closed crystal structures of a Group III CPN from the thermophilic bacterium Carboxydothermus hydrogenoformans, discuss its mechanism and structurally compare it with Group I and II CPNs.
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Affiliation(s)
- Young Jun An
- Marine Biotechnology Research Center, Korea Institute of Ocean Science and Technology, Ansan, 15627, Republic of Korea
| | - Sara E Rowland
- Department of Microbiology and Immunology, University of Maryland, Baltimore, MD, 21201, USA.,Institute of Marine and Environmental Technology, Baltimore, MD, 21201, USA
| | - Jung-Hyun Na
- Department of Chemistry & Nanoscience, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Dario Spigolon
- Department of Microbiology and Immunology, University of Maryland, Baltimore, MD, 21201, USA.,Institute of Marine and Environmental Technology, Baltimore, MD, 21201, USA
| | - Seung Kon Hong
- Department of Chemistry & Nanoscience, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Yeo Joon Yoon
- Department of Chemistry & Nanoscience, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Jung-Hyun Lee
- Marine Biotechnology Research Center, Korea Institute of Ocean Science and Technology, Ansan, 15627, Republic of Korea
| | - Frank T Robb
- Department of Microbiology and Immunology, University of Maryland, Baltimore, MD, 21201, USA. .,Institute of Marine and Environmental Technology, Baltimore, MD, 21201, USA.
| | - Sun-Shin Cha
- Department of Chemistry & Nanoscience, Ewha Womans University, Seoul, 03760, Republic of Korea.
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4
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Rapid Bioinformatic Identification of Thermostabilizing Mutations. Biophys J 2016; 109:1420-8. [PMID: 26445442 DOI: 10.1016/j.bpj.2015.07.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 07/03/2015] [Accepted: 07/14/2015] [Indexed: 11/21/2022] Open
Abstract
Ex vivo stability is a valuable protein characteristic but is laborious to improve experimentally. In addition to biopharmaceutical and industrial applications, stable protein is important for biochemical and structural studies. Taking advantage of the large number of available genomic sequences and growth temperature data, we present two bioinformatic methods to identify a limited set of amino acids or positions that likely underlie thermostability. Because these methods allow thousands of homologs to be examined in silico, they have the advantage of providing both speed and statistical power. Using these methods, we introduced, via mutation, amino acids from thermoadapted homologs into an exemplar mesophilic membrane protein, and demonstrated significantly increased thermostability while preserving protein activity.
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5
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Seo JH, Kim HH, Jeon EY, Song YH, Shin CS, Park JB. Engineering of Baeyer-Villiger monooxygenase-based Escherichia coli biocatalyst for large scale biotransformation of ricinoleic acid into (Z)-11-(heptanoyloxy)undec-9-enoic acid. Sci Rep 2016; 6:28223. [PMID: 27311560 PMCID: PMC4911592 DOI: 10.1038/srep28223] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 06/01/2016] [Indexed: 01/25/2023] Open
Abstract
Baeyer-Villiger monooxygenases (BVMOs) are able to catalyze regiospecific Baeyer-Villiger oxygenation of a variety of cyclic and linear ketones to generate the corresponding lactones and esters, respectively. However, the enzymes are usually difficult to express in a functional form in microbial cells and are rather unstable under process conditions hindering their large-scale applications. Thereby, we investigated engineering of the BVMO from Pseudomonas putida KT2440 and the gene expression system to improve its activity and stability for large-scale biotransformation of ricinoleic acid (1) into the ester (i.e., (Z)-11-(heptanoyloxy)undec-9-enoic acid) (3), which can be hydrolyzed into 11-hydroxyundec-9-enoic acid (5) (i.e., a precursor of polyamide-11) and n-heptanoic acid (4). The polyionic tag-based fusion engineering of the BVMO and the use of a synthetic promoter for constitutive enzyme expression allowed the recombinant Escherichia coli expressing the BVMO and the secondary alcohol dehydrogenase of Micrococcus luteus to produce the ester (3) to 85 mM (26.6 g/L) within 5 h. The 5 L scale biotransformation process was then successfully scaled up to a 70 L bioreactor; 3 was produced to over 70 mM (21.9 g/L) in the culture medium 6 h after biotransformation. This study demonstrated that the BVMO-based whole-cell reactions can be applied for large-scale biotransformations.
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Affiliation(s)
- Joo-Hyun Seo
- Department of Food Science and Engineering, Ewha Womans University, Seoul 120-750, Republic of Korea
| | - Hwan-Hee Kim
- Department of Food Science and Engineering, Ewha Womans University, Seoul 120-750, Republic of Korea
| | - Eun-Yeong Jeon
- Department of Food Science and Engineering, Ewha Womans University, Seoul 120-750, Republic of Korea
| | - Young-Ha Song
- AP Technology, Suwon, Kyunggi 443-702, Republic of Korea
| | - Chul-Soo Shin
- AP Technology, Suwon, Kyunggi 443-702, Republic of Korea
| | - Jin-Byung Park
- Department of Food Science and Engineering, Ewha Womans University, Seoul 120-750, Republic of Korea
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6
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Chaston JJ, Smits C, Aragão D, Wong ASW, Ahsan B, Sandin S, Molugu SK, Molugu SK, Bernal RA, Stock D, Stewart AG. Structural and Functional Insights into the Evolution and Stress Adaptation of Type II Chaperonins. Structure 2016; 24:364-74. [PMID: 26853941 DOI: 10.1016/j.str.2015.12.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 12/14/2015] [Accepted: 12/16/2015] [Indexed: 12/12/2022]
Abstract
Chaperonins are essential biological complexes assisting protein folding in all kingdoms of life. Whereas homooligomeric bacterial GroEL binds hydrophobic substrates non-specifically, the heterooligomeric eukaryotic CCT binds specifically to distinct classes of substrates. Sulfolobales, which survive in a wide range of temperatures, have evolved three different chaperonin subunits (α, β, γ) that form three distinct complexes tailored for different substrate classes at cold, normal, and elevated temperatures. The larger octadecameric β complexes cater for substrates under heat stress, whereas smaller hexadecameric αβ complexes prevail under normal conditions. The cold-shock complex contains all three subunits, consistent with greater substrate specificity. Structural analysis using crystallography and electron microscopy reveals the geometry of these complexes and shows a novel arrangement of the α and β subunits in the hexadecamer enabling incorporation of the γ subunit.
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Affiliation(s)
- Jessica J Chaston
- Molecular, Structural and Computational Biology Division, The Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; Faculty of Medicine, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Callum Smits
- Molecular, Structural and Computational Biology Division, The Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; Faculty of Medicine, The University of New South Wales, Sydney, NSW 2052, Australia
| | - David Aragão
- Australian Synchrotron, Clayton, VIC 3168, Australia
| | - Andrew S W Wong
- School of Biological Sciences, Nanyang Technological University, Singapore 637551; NTU Institute of Structural Biology, Nanyang Technological University, Singapore 637551
| | - Bilal Ahsan
- School of Biological Sciences, Nanyang Technological University, Singapore 637551
| | - Sara Sandin
- School of Biological Sciences, Nanyang Technological University, Singapore 637551; NTU Institute of Structural Biology, Nanyang Technological University, Singapore 637551
| | - Sudheer K Molugu
- Department of Chemistry, University of Texas at El Paso, El Paso, TX 79968, USA
| | - Sanjay K Molugu
- Department of Chemistry, University of Texas at El Paso, El Paso, TX 79968, USA
| | - Ricardo A Bernal
- Department of Chemistry, University of Texas at El Paso, El Paso, TX 79968, USA
| | - Daniela Stock
- Molecular, Structural and Computational Biology Division, The Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; Faculty of Medicine, The University of New South Wales, Sydney, NSW 2052, Australia.
| | - Alastair G Stewart
- Molecular, Structural and Computational Biology Division, The Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; School of Molecular Bioscience, The University of Sydney, Sydney, NSW 2006, Australia.
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7
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Gao L, Imanaka T, Fujiwara S. A Mutant Chaperonin That Is Functional at Lower Temperatures Enables Hyperthermophilic Archaea To Grow under Cold-Stress Conditions. J Bacteriol 2015; 197:2642-52. [PMID: 26013483 PMCID: PMC4507335 DOI: 10.1128/jb.00279-15] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 05/21/2015] [Indexed: 02/07/2023] Open
Abstract
UNLABELLED Thermococcus kodakarensis grows optimally at 85°C and possesses two chaperonins, cold-inducible CpkA and heat-inducible CpkB, which are involved in adaptation to low and high temperatures, respectively. The two chaperonins share a high sequence identity (77%), except in their C-terminal regions. CpkA, which contains tandem repeats of a GGM motif, shows its highest ATPase activity at 60°C to 70°C, whereas CpkB shows its highest activity at temperatures higher than 90°C. To clarify the effects of changes in ATPase activity on chaperonin function at lower temperatures, various CpkA variants were constructed by introducing single point mutations into the C-terminal region. A CpkA variant in which Glu530 was replaced with Gly (CpkA-E530G) showed increased ATPase activity, with its highest activity at 50°C. The efficacy of the CpkA variants against denatured indole-3-glycerol-phosphate synthase of T. kodakarensis (TrpCTk), which is a CpkA target, was then examined in vitro. CpkA-E530G was more effective than wild-type CpkA at facilitating the refolding of chemically unfolded TrpCTk at 50°C. The effect of cpkA-E530G on cell growth was then examined by introducing cpkA-E530G into the genome of T. kodakarensis KU216 (pyrF). The mutant strain, DA4 (pyrF cpkA-E530G), grew as well as the parental KU216 strain at 60°C. In contrast, DA4 grew more vigorously than KU216 at 50°C. These results suggested that the CpkA-E530G mutation prevented cold denaturation of proteins under cold-stress conditions, thereby enabling cells to grow in cooler environments. Thus, a single base pair substitution in a chaperonin gene allows cells to grow vigorously in a new environment. IMPORTANCE Thermococcus kodakarensis possesses two group II chaperonins, cold-inducible CpkA and heat-inducible CpkB, which are involved in adaptation to low and high temperatures, respectively. CpkA might act as an "adaptive allele" to adapt to cooler environments. In this study, we compared the last 20 amino acids within the C termini of the chaperonins and found a clear correlation between the CpkA-type chaperonin gene copy number and growth temperature. Furthermore, we introduced single mutations into the CpkA C-terminal region to clarify its role in cold adaptation, and we showed that a single base substitution allowed the organism to adapt to a lower temperature. The present data suggest that hyperthermophiles have evolved by obtaining mutations in chaperonins that allow them to adapt to a colder environment.
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Affiliation(s)
- Le Gao
- Research Center for Intelligent Bio-Materials, Graduate School of Science and Technology, Kwansei-Gakuin University, Sanda, Hyogo, Japan
| | - Tadayuki Imanaka
- Research Organization of Science and Technology, Ritsumeikan University, Kasatsu, Shiga, Japan
| | - Shinsuke Fujiwara
- Research Center for Intelligent Bio-Materials, Graduate School of Science and Technology, Kwansei-Gakuin University, Sanda, Hyogo, Japan Department of Bioscience, Graduate School of Science and Technology, Kwansei-Gakuin University, Sanda, Hyogo, Japan
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8
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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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9
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A human CCT5 gene mutation causing distal neuropathy impairs hexadecamer assembly in an archaeal model. Sci Rep 2014; 4:6688. [PMID: 25345891 PMCID: PMC4209464 DOI: 10.1038/srep06688] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 10/01/2014] [Indexed: 01/22/2023] Open
Abstract
Chaperonins mediate protein folding in a cavity formed by multisubunit rings. The human CCT has eight non-identical subunits and the His147Arg mutation in one subunit, CCT5, causes neuropathy. Knowledge is scarce on the impact of this and other mutations upon the chaperone's structure and functions. To make progress, experimental models must be developed. We used an archaeal mutant homolog and demonstrated that the His147Arg mutant has impaired oligomeric assembly, ATPase activity, and defective protein homeostasis functions. These results establish for the first time that a human chaperonin gene defect can be reproduced and studied at the molecular level with an archaeal homolog. The major advantage of the system, consisting of rings with eight identical subunits, is that it amplifies the effects of a mutation as compared with the human counterpart, in which just one subunit per ring is defective. Therefore, the slight deficit of a non-lethal mutation can be detected and characterized.
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10
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Kurouski D, Luo H, Sereda V, Robb FT, Lednev IK. Deconstruction of stable cross-Beta fibrillar structures into toxic and nontoxic products using a mutated archaeal chaperonin. ACS Chem Biol 2013; 8:2095-101. [PMID: 23875676 DOI: 10.1021/cb400238a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Our group recently determined that a mutant archaeal chaperonin (Hsp 60) exhibited substantially enhanced protein folding activity at low temperatures and was able to deconstruct refractory protein aggregates. ATP dependent conversion of fibril structures into amorphous aggregates was observed in insulin amyloid preparations (Kurouski et al. Biochem. Biophys. Res. Commun. 2012). In the current study, mechanistic insights into insulin fibril deconstruction were obtained by examination of early stage complexes between Hsp60 and fibrils in the absence of ATP. Activity of the Hsp60 was significantly curtailed without ATP; however, some fibril deconstruction occurred, which is consistent with some models of the folding cycle that predict initial removal of unproductive protein folds. Chaperonin molecules adsorbed on the fibril surface and formed chaperonin clusters with no ATP present. We propose that there are specific locations on the fibril surface where chaperonin can unravel the fibril to release short fragments. Spontaneous coagulation of these fibril fragments resulted in the formation of amorphous aggregates without the release of insulin into solution. The addition of ATP significantly increased the toxicity of the insulin fibril-chaperonin reaction products toward mammalian cells.
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Affiliation(s)
- Dmitry Kurouski
- Department of Chemistry, University
at Albany, State University of New York, Albany, New York 12222, United States
| | - Haibin Luo
- Department of Microbiology and
Immunology, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, Maryland 21201, United States
| | - Valentin Sereda
- Department of Chemistry, University
at Albany, State University of New York, Albany, New York 12222, United States
| | - Frank T. Robb
- Department of Microbiology and
Immunology, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, Maryland 21201, United States
| | - Igor K. Lednev
- Department of Chemistry, University
at Albany, State University of New York, Albany, New York 12222, United States
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11
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Zhang K, Wang L, Liu Y, Chan KY, Pang X, Schulten K, Dong Z, Sun F. Flexible interwoven termini determine the thermal stability of thermosomes. Protein Cell 2013; 4:432-44. [PMID: 23709365 DOI: 10.1007/s13238-013-3026-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Accepted: 04/26/2013] [Indexed: 01/27/2023] Open
Abstract
Group II chaperonins, which assemble as double-ring complexes, assist in the refolding of nascent peptides or denatured proteins in an ATP-dependent manner. The molecular mechanism of group II chaperonin assembly and thermal stability is yet to be elucidated. Here, we selected the group II chaperonins (cpn-α and cpn-β), also called thermosomes, from Acidianus tengchongensis and investigated their assembly and thermal stability. We found that the binding of ATP or its analogs contributed to the successful assembly of thermosomes and enhanced their thermal stabilities. Cpn-β is more thermally stable than cpn-α, while the thermal stability of the hetero thermosome cpn-αβ is intermediate. Cryo-electron microscopy reconstructions of cpn-α and cpn-β revealed the interwoven densities of their non-conserved flexible N/C-termini around the equatorial planes. The deletion or swapping of their termini and pH-dependent thermal stability assays revealed the key role of the termini electrostatic interactions in the assembly and thermal stability of the thermosomes.
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Affiliation(s)
- Kai Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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12
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Rapid degradation kinetics of amyloid fibrils under mild conditions by an archaeal chaperonin. Biochem Biophys Res Commun 2012; 422:97-102. [DOI: 10.1016/j.bbrc.2012.04.113] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 04/21/2012] [Indexed: 11/24/2022]
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13
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Indole-3-glycerol-phosphate synthase is recognized by a cold-inducible group II chaperonin in Thermococcus kodakarensis. Appl Environ Microbiol 2012; 78:3806-15. [PMID: 22447592 DOI: 10.1128/aem.07996-11] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Thermococcus kodakarensis optimally grows at 85°C and possesses two chaperonins, cold-inducible CpkA and heat-inducible CpkB. Gene disruptants DA1 (ΔcpkA) and DB1 (ΔcpkB) showed decreased cell growth at 60°C and 93°C, respectively. The DB2 mutant (ΔcpkAcpkB ΔcpkB), whose cpkB gene was expressed under the control of the cpkA promoter, did not grow at 60°C, and the DB3 mutant [ΔcpkA(1-524)cpkB(1-524) ΔcpkB], whose CpkA amino acid residues 1 to 524 were replaced with corresponding CpkB residues that maintained the C-terminal region intact, grew at 60°C, implying that the CpkA C-terminal region plays a key role in cell growth at 60°C. To screen for specific CpkA target proteins, comparative pulldown studies with anti-Cpk were performed using cytoplasmic fractions from DA1 cells cultivated at 93°C and DB1 cells cultivated at 60°C. Among the proteins coprecipitated with anti-Cpk, TK0252, encoding indole-3-glycerol-phosphate synthase (TrpC), showed the highest Mascot score. Counter-pulldown experiments were also performed on DA1 and DB1 extracts using anti-TrpC. CpkA coimmunoprecipitated with anti-TrpC while CpkB did not. The results obtained indicate that TrpC is a specific target for CpkA. The effects of Cpks on denatured TrpC were then examined. The refolding of partially denatured TrpC was accelerated by the addition of CpkA but not by adding CpkB. DA1 cells grew optimally in minimal medium only in the presence of tryptophan but hardly grew in the absence of tryptophan at 60°C. It has been suggested that a lesion of functional TrpC is caused by cpkA disruption, resulting in tryptophan auxotrophy.
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14
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Luo H, Zhang P, Robb FT. Oligomerization of an archaeal group II chaperonin is mediated by N-terminal salt bridges. Biochem Biophys Res Commun 2011; 413:389-94. [DOI: 10.1016/j.bbrc.2011.08.112] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Accepted: 08/23/2011] [Indexed: 11/30/2022]
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