1
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Harkness RW, Zhao H, Toyama Y, Schuck P, Kay LE. Exploring Host-Guest Interactions within a 600 kDa DegP Protease Cage Complex Using Hydrodynamics Measurements and Methyl-TROSY NMR. J Am Chem Soc 2024; 146:8242-8259. [PMID: 38477967 DOI: 10.1021/jacs.3c13247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2024]
Abstract
The DegP protease-chaperone operates within the periplasm of Gram-negative bacteria, where it assists in the regulation of protein homeostasis, promotes virulence, and is essential to survival under stress. To carry out these tasks, DegP forms a network of preorganized apo oligomers that facilitate the capture of substrates within distributions of cage-like complexes which expand to encapsulate clients of various sizes. Although the architectures of DegP cage complexes are well understood, little is known about the structures, dynamics, and interactions of client proteins within DegP cages and the relationship between client structural dynamics and function. Here, we probe host-guest interactions within a 600 kDa DegP cage complex throughout the DegP activation cycle using a model α-helical client protein through a combination of hydrodynamics measurements, methyl-transverse relaxation optimized spectroscopy-based solution nuclear magnetic resonance studies, and proteolytic activity assays. We find that in the presence of the client, DegP cages assemble cooperatively with few intermediates. Our data further show that the N-terminal half of the bound client, which projects into the interior of the cages, is predominantly unfolded and flexible, and exchanges between multiple conformational states over a wide range of time scales. Finally, we show that a concerted structural transition of the protease domains of DegP occurs upon client engagement, leading to activation. Together, our findings support a model of DegP as a highly cooperative and dynamic molecular machine that stabilizes unfolded states of clients, primarily via interactions with their C-termini, giving rise to efficient cleavage.
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Affiliation(s)
- Robert W Harkness
- Department of Biochemistry, University of Toronto, Toronto M5S 1A8, Canada
- Department of Molecular Genetics, University of Toronto, Toronto M5S 1A8, Canada
- Department of Chemistry, University of Toronto, Toronto M5S 3H6, Canada
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto M5G 0A4, Canada
| | - Huaying Zhao
- Laboratory of Dynamics of Macromolecular Assembly, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Yuki Toyama
- Department of Biochemistry, University of Toronto, Toronto M5S 1A8, Canada
- Department of Molecular Genetics, University of Toronto, Toronto M5S 1A8, Canada
- Department of Chemistry, University of Toronto, Toronto M5S 3H6, Canada
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto M5G 0A4, Canada
| | - Peter Schuck
- Laboratory of Dynamics of Macromolecular Assembly, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Lewis E Kay
- Department of Biochemistry, University of Toronto, Toronto M5S 1A8, Canada
- Department of Molecular Genetics, University of Toronto, Toronto M5S 1A8, Canada
- Department of Chemistry, University of Toronto, Toronto M5S 3H6, Canada
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto M5G 0A4, Canada
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2
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Ronzetti M, Baljinnyam B, Jalal I, Pal U, Simeonov A. Application of biophysical methods for improved protein production and characterization: A case study on an high-temperature requirement A-family bacterial protease. Protein Sci 2022; 31:e4498. [PMID: 36334045 PMCID: PMC9679970 DOI: 10.1002/pro.4498] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 11/02/2022] [Accepted: 11/02/2022] [Indexed: 11/07/2022]
Abstract
The high-temperature requirement A (HtrA) serine protease family presents an attractive target class for antibacterial therapeutics development. These proteins possess dual protease and chaperone functions and contain numerous binding sites and regulatory loops, displaying diverse oligomerization patterns dependent on substrate type and occupancy. HtrA proteins that are natively purified coelute with contaminating peptides and activating species, shifting oligomerization and protein structure to differently activated populations. Here, a redesigned HtrA production results in cleaner preparations with high yields by overexpressing and purifying target protein from inclusion bodies under denaturing conditions, followed by a high-throughput screen for optimal refolding buffer composition using function-agnostic biophysical techniques that do not rely on target-specific measurements. We use Borrelia burgdorferi HtrA to demonstrate the effectiveness of our function-agnostic approach, while characterization with both new and established biophysical methods shows the retention of proteolytic and chaperone activity of the refolded protein. This systematic workflow and toolset will translate to the production of HtrA-family proteins in higher quantities of pure and monodisperse composition than the current literature standard, with applicability to a broad array of protein purification strategies.
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Affiliation(s)
- Michael Ronzetti
- National Center for Advancing Translational SciencesNational Institutes of HealthRockvilleMarylandUSA
- Department of Veterinary Medicine, College of Agriculture & Natural ResourcesUniversity of MarylandCollege ParkMarylandUSA
| | - Bolormaa Baljinnyam
- National Center for Advancing Translational SciencesNational Institutes of HealthRockvilleMarylandUSA
| | | | - Utpal Pal
- Department of Veterinary Medicine, College of Agriculture & Natural ResourcesUniversity of MarylandCollege ParkMarylandUSA
| | - Anton Simeonov
- National Center for Advancing Translational SciencesNational Institutes of HealthRockvilleMarylandUSA
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3
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Šulskis D, Thoma J, Burmann BM. Structural basis of DegP protease temperature-dependent activation. SCIENCE ADVANCES 2021; 7:eabj1816. [PMID: 34878848 PMCID: PMC8654288 DOI: 10.1126/sciadv.abj1816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 10/16/2021] [Indexed: 05/21/2023]
Abstract
Protein quality control is an essential cellular function mainly executed by a vast array of different proteases and molecular chaperones. One of the bacterial high temperature requirement A (HtrA) protein family members, the homo-oligomeric DegP protease, plays a crucial role in the Escherichia coli protein quality control machinery by removing unfolded proteins or preventing their aggregation and chaperoning them to their final folded state within the periplasm. DegP contains two regulatory PDZ domains, which play key roles in substrate recognition and in the transformation of DegP between inactive hexameric and proteolytic active cage-like structures. Here, we analyze the interaction and dynamics of the DegP PDZ domains underlying this transformation by high-resolution NMR spectroscopy complemented with biochemical cleavage assays. We identify an interdomain molecular lock, which controls the interactions between the two PDZ domains, regulated by fine-tuned temperature-dependent protein dynamics, and which is potentially conserved in proteins harboring tandem PDZ domains.
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Affiliation(s)
- Darius Šulskis
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, 405 30 Göteborg, Sweden
| | - Johannes Thoma
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, 405 30 Göteborg, Sweden
| | - Björn M. Burmann
- Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30 Göteborg, Sweden
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, 405 30 Göteborg, Sweden
- Corresponding author.
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4
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Abstract
Native mass spectrometry (MS) is aimed at preserving and determining the native structure, composition, and stoichiometry of biomolecules and their complexes from solution after they are transferred into the gas phase. Major improvements in native MS instrumentation and experimental methods over the past few decades have led to a concomitant increase in the complexity and heterogeneity of samples that can be analyzed, including protein-ligand complexes, protein complexes with multiple coexisting stoichiometries, and membrane protein-lipid assemblies. Heterogeneous features of these biomolecular samples can be important for understanding structure and function. However, sample heterogeneity can make assignment of ion mass, charge, composition, and structure very challenging due to the overlap of tens or even hundreds of peaks in the mass spectrum. In this review, we cover data analysis, experimental, and instrumental advances and strategies aimed at solving this problem, with an in-depth discussion of theoretical and practical aspects of the use of available deconvolution algorithms and tools. We also reflect upon current challenges and provide a view of the future of this exciting field.
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Affiliation(s)
- Amber D Rolland
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403-1253, United States
| | - James S Prell
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, Oregon 97403-1253, United States.,Materials Science Institute, University of Oregon, Eugene, Oregon 97403-1252, United States
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5
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Kim H, Wu K, Lee C. Stress-Responsive Periplasmic Chaperones in Bacteria. Front Mol Biosci 2021; 8:678697. [PMID: 34046432 PMCID: PMC8144458 DOI: 10.3389/fmolb.2021.678697] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 04/19/2021] [Indexed: 01/14/2023] Open
Abstract
Periplasmic proteins are involved in a wide range of bacterial functions, including motility, biofilm formation, sensing environmental cues, and small-molecule transport. In addition, a wide range of outer membrane proteins and proteins that are secreted into the media must travel through the periplasm to reach their final destinations. Since the porous outer membrane allows for the free diffusion of small molecules, periplasmic proteins and those that travel through this compartment are more vulnerable to external environmental changes, including those that result in protein unfolding, than cytoplasmic proteins are. To enable bacterial survival under various stress conditions, a robust protein quality control system is required in the periplasm. In this review, we focus on several periplasmic chaperones that are stress responsive, including Spy, which responds to envelope-stress, DegP, which responds to temperature to modulate chaperone/protease activity, HdeA and HdeB, which respond to acid stress, and UgpB, which functions as a bile-responsive chaperone.
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Affiliation(s)
- Hyunhee Kim
- Department of Biological Sciences, Ajou University, Suwon, South Korea
- Molecular, Cellular, and Developmental Biology, Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI, United States
| | - Kevin Wu
- Molecular, Cellular, and Developmental Biology, Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI, United States
- Department of Biophysics, University of Michigan, Ann Arbor, MI, United States
| | - Changhan Lee
- Department of Biological Sciences, Ajou University, Suwon, South Korea
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6
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Exploring the structure and dynamics of macromolecular complexes by native mass spectrometry. J Proteomics 2020; 222:103799. [DOI: 10.1016/j.jprot.2020.103799] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 03/23/2020] [Accepted: 04/25/2020] [Indexed: 12/15/2022]
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7
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Merdanovic M, Burston SG, Schmitz AL, Köcher S, Knapp S, Clausen T, Kaiser M, Huber R, Ehrmann M. Activation by substoichiometric inhibition. Proc Natl Acad Sci U S A 2020; 117:1414-1418. [PMID: 31907318 PMCID: PMC6983408 DOI: 10.1073/pnas.1918721117] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Startling reports described the paradoxical triggering of the human mitogen-activated protein kinase pathway when a small-molecule inhibitor specifically inactivates the BRAF V600E protein kinase but not wt-BRAF. We performed a conceptual analysis of the general phenomenon "activation by inhibition" using bacterial and human HtrA proteases as models. Our data suggest a clear explanation that is based on the classic biochemical principles of allostery and cooperativity. Although substoichiometric occupancy of inhibitor binding sites results in partial inhibition, this effect is overrun by a concomitant activation of unliganded binding sites. Therefore, when an inhibitor of a cooperative enzyme does not reach saturating levels, a common scenario during drug administration, it may cause the contrary of the desired effect. The implications for drug development are discussed.
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Affiliation(s)
- Melisa Merdanovic
- Center of Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, 45117 Essen, Germany
| | - Steven G Burston
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, Bristol BS8 1TD, United Kingdom
| | - Anna Laura Schmitz
- Center of Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, 45117 Essen, Germany
| | - Steffen Köcher
- Center of Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, 45117 Essen, Germany
| | - Stefan Knapp
- Institute of Pharmaceutical Chemistry, Goethe-University Frankfurt, 60438 Frankfurt, Germany
| | - Tim Clausen
- Research Institute of Molecular Pathology, 1030 Vienna, Austria
| | - Markus Kaiser
- Center of Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, 45117 Essen, Germany
| | - Robert Huber
- Center of Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, 45117 Essen, Germany;
- Max-Planck-Institute of Biochemistry, 82152 Martinsried, Germany
| | - Michael Ehrmann
- Center of Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, 45117 Essen, Germany;
- School of Biosciences, Cardiff University, Cardiff CF10 3US, United Kingdom
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8
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Bravo-Rodriguez K, Hagemeier B, Drescher L, Lorenz M, Rey J, Meltzer M, Kaschani F, Kaiser M, Ehrmann M. Utilities for Mass Spectrometry Analysis of Proteins (UMSAP): Fast post-processing of mass spectrometry data. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2018; 32:1659-1667. [PMID: 30062799 DOI: 10.1002/rcm.8243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 07/13/2018] [Accepted: 07/16/2018] [Indexed: 06/08/2023]
Abstract
RATIONALE Mass spectrometry (MS) is an invaluable tool for the analysis of proteins. However, the sheer amount of data generated in MS studies demands dedicated data-processing tools that are efficient and require minimal user intervention. METHODS Utilities for Mass Spectrometry Analysis of Proteins (UMSAP) is a graphical user interface designed for efficient post-processing of MS result files. The software is written in Tcl/Tk and can be used in Windows, OS X or Linux. No third party programs or libraries are required. Currently, UMSAP can process data obtained from proteolytic degradation experiments and generates graphical outputs allowing a straightforward interpretation of statistically relevant results. RESULTS UMSAP is used here to analyze the proteolytic degradation of glycerophosphoryl diester phosphodiesterase GlpQ by the protein quality control protease DegP. Mass spectrometry was used to monitor proteolysis over time in the absence and presence of a peptidic allosteric activator of DegP. The software's output clearly shows the increased proteolytic activity of DegP in the presence of the activating peptide, identifies statistically significant products of the proteolysis and offers valuable insights into substrate specificity. CONCLUSIONS Utilities for Mass Spectrometry Analysis of Proteins is an open-source software designed for efficient post-processing of large datasets obtained by MS analyses of proteins. In addition, the modular architecture of the software allows easy incorporation of new modules to analyze various experimental mass spectrometry setups.
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Affiliation(s)
- Kenny Bravo-Rodriguez
- Centre of Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Universitätsstraße, 45117, Essen, Germany
| | - Birte Hagemeier
- Centre of Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Universitätsstraße, 45117, Essen, Germany
| | - Lea Drescher
- Centre of Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Universitätsstraße, 45117, Essen, Germany
| | - Marian Lorenz
- Centre of Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Universitätsstraße, 45117, Essen, Germany
| | - Juliana Rey
- Centre of Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Universitätsstraße, 45117, Essen, Germany
| | - Michael Meltzer
- Centre of Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Universitätsstraße, 45117, Essen, Germany
| | - Farnusch Kaschani
- Centre of Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Universitätsstraße, 45117, Essen, Germany
| | - Markus Kaiser
- Centre of Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Universitätsstraße, 45117, Essen, Germany
| | - Michael Ehrmann
- Centre of Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Universitätsstraße, 45117, Essen, Germany
- School of Biosciences, Cardiff University, Cardiff, CF10 3AT, UK
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9
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He D, Xie X, Yang F, Zhang H, Su H, Ge Y, Song H, Chen PR. Quantitative and Comparative Profiling of Protease Substrates through a Genetically Encoded Multifunctional Photocrosslinker. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201708151] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Dan He
- Synthetic and Functional Biomolecules Center; Beijing National Laboratory for Molecular Sciences; Department of Chemical Biology; College of Chemistry and Molecular Engineering; Peking University; Beijing 100871 China
| | - Xiao Xie
- Synthetic and Functional Biomolecules Center; Beijing National Laboratory for Molecular Sciences; Department of Chemical Biology; College of Chemistry and Molecular Engineering; Peking University; Beijing 100871 China
| | - Fan Yang
- Synthetic and Functional Biomolecules Center; Beijing National Laboratory for Molecular Sciences; Department of Chemical Biology; College of Chemistry and Molecular Engineering; Peking University; Beijing 100871 China
| | - Heng Zhang
- Synthetic and Functional Biomolecules Center; Beijing National Laboratory for Molecular Sciences; Department of Chemical Biology; College of Chemistry and Molecular Engineering; Peking University; Beijing 100871 China
| | - Haomiao Su
- College of Chemistry and Molecular Sciences; Wuhan University; Wuhan 430072 China
| | - Yun Ge
- Synthetic and Functional Biomolecules Center; Beijing National Laboratory for Molecular Sciences; Department of Chemical Biology; College of Chemistry and Molecular Engineering; Peking University; Beijing 100871 China
| | - Haiping Song
- Synthetic and Functional Biomolecules Center; Beijing National Laboratory for Molecular Sciences; Department of Chemical Biology; College of Chemistry and Molecular Engineering; Peking University; Beijing 100871 China
| | - Peng R. Chen
- Synthetic and Functional Biomolecules Center; Beijing National Laboratory for Molecular Sciences; Department of Chemical Biology; College of Chemistry and Molecular Engineering; Peking University; Beijing 100871 China
- Peking-Tsinghua Center for Life Sciences; Peking University; Beijing 100871 China
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10
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He D, Xie X, Yang F, Zhang H, Su H, Ge Y, Song H, Chen PR. Quantitative and Comparative Profiling of Protease Substrates through a Genetically Encoded Multifunctional Photocrosslinker. Angew Chem Int Ed Engl 2017; 56:14521-14525. [DOI: 10.1002/anie.201708151] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 09/14/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Dan He
- Synthetic and Functional Biomolecules Center; Beijing National Laboratory for Molecular Sciences; Department of Chemical Biology; College of Chemistry and Molecular Engineering; Peking University; Beijing 100871 China
| | - Xiao Xie
- Synthetic and Functional Biomolecules Center; Beijing National Laboratory for Molecular Sciences; Department of Chemical Biology; College of Chemistry and Molecular Engineering; Peking University; Beijing 100871 China
| | - Fan Yang
- Synthetic and Functional Biomolecules Center; Beijing National Laboratory for Molecular Sciences; Department of Chemical Biology; College of Chemistry and Molecular Engineering; Peking University; Beijing 100871 China
| | - Heng Zhang
- Synthetic and Functional Biomolecules Center; Beijing National Laboratory for Molecular Sciences; Department of Chemical Biology; College of Chemistry and Molecular Engineering; Peking University; Beijing 100871 China
| | - Haomiao Su
- College of Chemistry and Molecular Sciences; Wuhan University; Wuhan 430072 China
| | - Yun Ge
- Synthetic and Functional Biomolecules Center; Beijing National Laboratory for Molecular Sciences; Department of Chemical Biology; College of Chemistry and Molecular Engineering; Peking University; Beijing 100871 China
| | - Haiping Song
- Synthetic and Functional Biomolecules Center; Beijing National Laboratory for Molecular Sciences; Department of Chemical Biology; College of Chemistry and Molecular Engineering; Peking University; Beijing 100871 China
| | - Peng R. Chen
- Synthetic and Functional Biomolecules Center; Beijing National Laboratory for Molecular Sciences; Department of Chemical Biology; College of Chemistry and Molecular Engineering; Peking University; Beijing 100871 China
- Peking-Tsinghua Center for Life Sciences; Peking University; Beijing 100871 China
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11
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Korasick DA, Gamage TT, Christgen S, Stiers KM, Beamer LJ, Henzl MT, Becker DF, Tanner JJ. Structure and characterization of a class 3B proline utilization A: Ligand-induced dimerization and importance of the C-terminal domain for catalysis. J Biol Chem 2017; 292:9652-9665. [PMID: 28420730 PMCID: PMC5465489 DOI: 10.1074/jbc.m117.786855] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Revised: 04/12/2017] [Indexed: 12/23/2022] Open
Abstract
The bifunctional flavoenzyme proline utilization A (PutA) catalyzes the two-step oxidation of proline to glutamate using separate proline dehydrogenase (PRODH) and l-glutamate-γ-semialdehyde dehydrogenase active sites. Because PutAs catalyze sequential reactions, they are good systems for studying how metabolic enzymes communicate via substrate channeling. Although mechanistically similar, PutAs vary widely in domain architecture, oligomeric state, and quaternary structure, and these variations represent different structural solutions to the problem of sequestering a reactive metabolite. Here, we studied PutA from Corynebacterium freiburgense (CfPutA), which belongs to the uncharacterized 3B class of PutAs. A 2.7 Å resolution crystal structure showed the canonical arrangement of PRODH, l-glutamate-γ-semialdehyde dehydrogenase, and C-terminal domains, including an extended interdomain tunnel associated with substrate channeling. The structure unexpectedly revealed a novel open conformation of the PRODH active site, which is interpreted to represent the non-activated conformation, an elusive form of PutA that exhibits suboptimal channeling. Nevertheless, CfPutA exhibited normal substrate-channeling activity, indicating that it isomerizes into the active state under assay conditions. Sedimentation-velocity experiments provided insight into the isomerization process, showing that CfPutA dimerizes in the presence of a proline analog and NAD+ These results are consistent with the morpheein model of enzyme hysteresis, in which substrate binding induces conformational changes that promote assembly of a high-activity oligomer. Finally, we used domain deletion analysis to investigate the function of the C-terminal domain. Although this domain contains neither catalytic residues nor substrate sites, its removal impaired both catalytic activities, suggesting that it may be essential for active-site integrity.
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Affiliation(s)
| | | | - Shelbi Christgen
- Department of Biochemistry and Redox Biology Center, University of Nebraska, Lincoln, Nebraska 68588
| | | | | | | | - Donald F Becker
- Department of Biochemistry and Redox Biology Center, University of Nebraska, Lincoln, Nebraska 68588
| | - John J Tanner
- From the Departments of Biochemistry and
- Chemistry, University of Missouri, Columbia, Missouri 65211, and
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12
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Abstract
The β-barrel outer membrane proteins (OMPs) are integral membrane proteins that reside in the outer membrane of Gram-negative bacteria and perform a diverse range of biological functions. Synthesized in the cytoplasm, OMPs must be transported across the inner membrane and through the periplasmic space before they are assembled in the outer membrane. In Escherichia coli, Skp, SurA and DegP are the most prominent factors identified to guide OMPs across the periplasm and to play the role of quality control. Although extensive genetic and biochemical analyses have revealed many basic functions of these periplasmic proteins, the mechanism of their collaboration in assisting the folding and insertion of OMPs is much less understood. Recently, biophysical approaches have shed light on the identification of the intricate network. In the present review, we summarize recent advances in the characterization of these key factors, with a special emphasis on the multifunctional protein DegP. In addition, we present our proposed model on the periplasmic quality control in biogenesis of OMPs.
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13
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Bodelón G, Marín E, Fernández LÁ. Analyzing the Role of Periplasmic Folding Factors in the Biogenesis of OMPs and Members of the Type V Secretion System. Methods Mol Biol 2015; 1329:77-110. [PMID: 26427678 DOI: 10.1007/978-1-4939-2871-2_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
The outer membrane (OM) of gram-negative bacteria is highly packed with OM proteins (OMPs) and the trafficking and assembly of OMPs in gram-negative bacteria is a subject of intense research. Structurally, OMPs vary in the number of β-strands and in the size and complexity of extra-membrane domains, with extreme examples being the members of the type V protein secretion system (T5SS), such as the autotransporter (AT) and intimin/invasin families of secreted proteins, in which a large extracellular "passenger" domain is linked to a β-barrel that inserts in the OM. Despite their structural and functional diversity, OMPs interact in the periplasm with a relatively small set of protein chaperones that facilitate their transport from the inner membrane (IM) to the β-barrel assembly machinery (BAM complex), preventing aggregation and assisting their folding in various aspects including disulfide bond formation. This chapter is focused on the periplasmic folding factors involved in the biogenesis of integral OMPs and members of T5SS in E. coli, which are used as a model system in this field. Background information on these periplasmic folding factors is provided along with genetic methods to generate conditional mutants that deplete these factors from E. coli and biochemical methods to analyze the folding, surface display, disulfide formation and oligomerization state of OMPs/T5SS in these mutants.
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Affiliation(s)
- Gustavo Bodelón
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, 28049, Madrid, Spain
| | - Elvira Marín
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, 28049, Madrid, Spain
| | - Luis Ángel Fernández
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), Campus de Cantoblanco, 28049, Madrid, Spain.
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14
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Sharon M, Horovitz A. Probing allosteric mechanisms using native mass spectrometry. Curr Opin Struct Biol 2015; 34:7-16. [PMID: 26005781 DOI: 10.1016/j.sbi.2015.05.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Revised: 05/01/2015] [Accepted: 05/04/2015] [Indexed: 11/16/2022]
Abstract
Native mass spectrometry (MS) and ion mobility MS provide a way to discriminate between various allosteric mechanisms that cannot be distinguished using ensemble measurements of ligand binding in bulk protein solutions. Native MS, which yields mass measurements of intact assemblies, can be used to determine the values of ligand binding constants of multimeric allosteric proteins, thereby providing a way to distinguish, for example, between concerted and sequential allosteric models. Native MS can also be employed to study cooperativity owing to ligand-modulated protein oligomerization. The rotationally averaged cross-section areas of complexes obtained by ion mobility MS can be used to distinguish between induced fit and conformational selection. Native MS and its allied techniques are, therefore, becoming increasingly powerful tools for dissecting allosteric mechanisms.
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Affiliation(s)
- Michal Sharon
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Amnon Horovitz
- Department of Structural Biology, Weizmann Institute of Science, Rehovot 7610001, Israel.
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15
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Rai N, Ramaswamy A. Temperature dependent dynamics of DegP-trimer: A molecular dynamics study. Comput Struct Biotechnol J 2015; 13:329-38. [PMID: 25987966 PMCID: PMC4434178 DOI: 10.1016/j.csbj.2015.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 04/15/2015] [Accepted: 04/18/2015] [Indexed: 11/18/2022] Open
Abstract
DegP is a heat shock protein from high temperature requirement protease A family, which reacts to the environmental stress conditions in an ATP independent way. The objective of the present analysis emerged from the temperature dependent functional diversity of DegP between chaperonic and protease activities at temperatures below and above 28 °C, respectively. DegP is a multimeric protein and the minimal functional unit, DegP-trimer, is of great importance in understanding the DegP pathway. The structural aspects of DegP-trimer with respect to temperature variation have been studied using molecular dynamics simulations (for 100 ns) and principal component analysis to highlight the temperature dependent dynamics facilitating its functional diversity. The DegP-trimer revealed a pronounced dynamics at both 280 and 320 K, when compared to the dynamics observed at 300 K. The LA loop is identified as the highly flexible region during dynamics and at extreme temperatures, the residues 46–80 of LA loop express a flip towards right (at 280) and left ( at 320 K) with respect to the fixed β-sheet connecting the LA loop of protease for which Phe46 acts as one of the key residues. Such dynamics of LA loop facilitates inter-monomeric interaction with the PDZ1 domain of the neighbouring monomer and explains its active participation when DegP exists as trimer. Hence, the LA loop mediated dynamics of DegP-trimer is expected to provide further insight into the temperature dependent dynamics of DegP towards the understanding of its assembly and functional diversity in the presence of substrate.
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Affiliation(s)
- Nivedita Rai
- Centre for Bioinformatics, School of Life Sciences, Pondicherry University, Puducherry 605014, India
| | - Amutha Ramaswamy
- Centre for Bioinformatics, School of Life Sciences, Pondicherry University, Puducherry 605014, India
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Boeri Erba E, Petosa C. The emerging role of native mass spectrometry in characterizing the structure and dynamics of macromolecular complexes. Protein Sci 2015; 24:1176-92. [PMID: 25676284 DOI: 10.1002/pro.2661] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 02/06/2015] [Accepted: 02/06/2015] [Indexed: 12/31/2022]
Abstract
Mass spectrometry (MS) is a powerful tool for determining the mass of biomolecules with high accuracy and sensitivity. MS performed under so-called "native conditions" (native MS) can be used to determine the mass of biomolecules that associate noncovalently. Here we review the application of native MS to the study of protein-ligand interactions and its emerging role in elucidating the structure of macromolecular assemblies, including soluble and membrane protein complexes. Moreover, we discuss strategies aimed at determining the stoichiometry and topology of subunits by inducing partial dissociation of the holo-complex. We also survey recent developments in "native top-down MS", an approach based on Fourier Transform MS, whereby covalent bonds are broken without disrupting non-covalent interactions. Given recent progress, native MS is anticipated to play an increasingly important role for researchers interested in the structure of macromolecular complexes.
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Affiliation(s)
- Elisabetta Boeri Erba
- Université Grenoble Alpes, Institut de Biologie Structurale (IBS), 71 Avenue des Martyrs, F-38044, Grenoble, France.,Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), DSV, IBS, F-38044, Grenoble, France.,Centre National de la Recherche Scientifique (CNRS), IBS, F-38044, Grenoble, France
| | - Carlo Petosa
- Université Grenoble Alpes, Institut de Biologie Structurale (IBS), 71 Avenue des Martyrs, F-38044, Grenoble, France.,Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), DSV, IBS, F-38044, Grenoble, France.,Centre National de la Recherche Scientifique (CNRS), IBS, F-38044, Grenoble, France
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