1
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Seifi B, Wallin S. Impact of N-Terminal Domain Conformation and Domain Interactions on RfaH Fold Switching. Proteins 2024. [PMID: 39400465 DOI: 10.1002/prot.26755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 08/30/2024] [Accepted: 09/26/2024] [Indexed: 10/15/2024]
Abstract
RfaH is a two-domain metamorphic protein involved in transcription regulation and translation initiation. To carry out its dual functions, RfaH relies on two coupled structural changes: Domain dissociation and fold switching. In the free state, the C-terminal domain (CTD) of RfaH adopts an all-α fold and is tightly associated with the N-terminal domain (NTD). Upon binding to RNA polymerase (RNAP), the domains dissociate and the CTD transforms into an all-β fold while the NTD remains largely, but not entirely, unchanged. We test the idea that a change in the conformation of an extended β-hairpin (β3-β4) located on the NTD, helps trigger domain dissociation. To this end, we use homology modeling to construct a structure, H1, which is similar to free RfaH but with a remodeled β3-β4 hairpin. We then use an all-atom physics-based model enhanced with a dual basin structure-based potential to simulate domain separation driven by the thermal unfolding of the CTD with NTD in a fixed, folded conformation. We apply our model to both free RfaH and H1. For H1 we find, in line with our hypothesis, that the CTD exhibits lower stability and the domains dissociate at a lower temperature T, as compared to free RfaH. We do not, however, observe complete refolding to the all-β state in these simulations, suggesting that a change in β3-β4 orientation aids in, but is not sufficient for, domain dissociation. In addition, we study the reverse fold switch in which RfaH returns from a domain-open all-β state to its domain-closed all-α state. We observe a T-dependent transition rate; fold switching is slow at low T, where the CTD tends to be kinetically trapped in its all-β state, and at high-T, where the all-α state becomes unstable. Consequently, our simulations suggest an optimal T at which fold switching is most rapid. At this T, the stabilities of both folds are reduced. Overall, our study suggests that both inter-domain interactions and conformational changes within NTD may be important for the proper functioning of RfaH.
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Affiliation(s)
- Bahman Seifi
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St Johns, NL, Canada
| | - Stefan Wallin
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St Johns, NL, Canada
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2
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Gentili PL. The Conformational Contribution to Molecular Complexity and Its Implications for Information Processing in Living Beings and Chemical Artificial Intelligence. Biomimetics (Basel) 2024; 9:121. [PMID: 38392167 PMCID: PMC10886813 DOI: 10.3390/biomimetics9020121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 02/16/2024] [Accepted: 02/17/2024] [Indexed: 02/24/2024] Open
Abstract
This work highlights the relevant contribution of conformational stereoisomers to the complexity and functions of any molecular compound. Conformers have the same molecular and structural formulas but different orientations of the atoms in the three-dimensional space. Moving from one conformer to another is possible without breaking covalent bonds. The interconversion is usually feasible through the thermal energy available in ordinary conditions. The behavior of most biopolymers, such as enzymes, antibodies, RNA, and DNA, is understandable if we consider that each exists as an ensemble of conformers. Each conformational collection confers multi-functionality and adaptability to the single biopolymers. The conformational distribution of any biopolymer has the features of a fuzzy set. Hence, every compound that exists as an ensemble of conformers allows the molecular implementation of a fuzzy set. Since proteins, DNA, and RNA work as fuzzy sets, it is fair to say that life's logic is fuzzy. The power of processing fuzzy logic makes living beings capable of swift decisions in environments dominated by uncertainty and vagueness. These performances can be implemented in chemical robots, which are confined molecular assemblies mimicking unicellular organisms: they are supposed to help humans "colonise" the molecular world to defeat diseases in living beings and fight pollution in the environment.
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Affiliation(s)
- Pier Luigi Gentili
- Department of Chemistry, Biology, and Biotechnology, Università degli Studi di Perugia, 06123 Perugia, Italy
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3
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Meadows J, Röder K. The Effect of Pulling and Twisting Forces on Chameleon Sequence Peptides. Chemphyschem 2023; 24:e202300351. [PMID: 37818741 DOI: 10.1002/cphc.202300351] [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: 05/16/2023] [Revised: 10/06/2023] [Accepted: 10/06/2023] [Indexed: 10/13/2023]
Abstract
Chameleon sequences are amino acid sequences found in several distinct configurations in experiment. They challenge our understanding of the link between sequence and structure, and provide insight into structural competition in proteins. Here, we study the energy landscapes for three such sequences, and interrogate how pulling and twisting forces impact the available structural ensembles. Chameleon sequences do not necessarily exhibit multiple structural ensembles on a multifunnel energy landscape when we consider them in isolation. The application of even small forces leads to drastic changes in the energy landscapes. For pulling forces, we observe transitions from helical to extended structures in a very small span of forces. For twisting forces, the picture is much more complex, and highly dependent on the magnitude and handedness of the applied force as well as the reference angle for the twist. Depending on these parameters, more complex and more simplistic energy landscapes are observed alongside more and less diverse structural ensembles. The impact of even small forces is significant, confirming their likely role in folding events. In addition, small forces exerted by the remaining scaffold of a protein may be sufficient to lead to the adoption of a specific structural ensemble by a chameleon sequence.
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Affiliation(s)
- James Meadows
- Department of Chemistry, Durham University, Stockton Road, Durham, DH1 3LE, UK
- Previous affiliation: Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Konstantin Röder
- Randall Centre for Cell & Molecular Biophysics, King's College London, Guy's Campus, Great Maze Pond, London, SE1 1UL, UK
- Previous affiliation: Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
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4
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Tozzi A, Mazzeo M. The First Nucleic Acid Strands May Have Grown on Peptides via Primeval Reverse Translation. Acta Biotheor 2023; 71:23. [PMID: 37947915 DOI: 10.1007/s10441-023-09474-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 10/25/2023] [Indexed: 11/12/2023]
Abstract
The central dogma of molecular biology dictates that, with only a few exceptions, information proceeds from DNA to protein through an RNA intermediate. Examining the enigmatic steps from prebiotic to biological chemistry, we take another road suggesting that primordial peptides acted as template for the self-assembly of the first nucleic acids polymers. Arguing in favour of a sort of archaic "reverse translation" from proteins to RNA, our basic premise is a Hadean Earth where key biomolecules such as amino acids, polypeptides, purines, pyrimidines, nucleosides and nucleotides were available under different prebiotically plausible conditions, including meteorites delivery, shallow ponds and hydrothermal vents scenarios. Supporting a protein-first scenario alternative to the RNA world hypothesis, we propose the primeval occurrence of short two-dimensional peptides termed "selective amino acid- and nucleotide-matching oligopeptides" (henceforward SANMAOs) that noncovalently bind at the same time the polymerized amino acids and the single nucleotides dispersed in the prebiotic milieu. In this theoretical paper, we describe the chemical features of this hypothetical oligopeptide, its biological plausibility and its virtues from an evolutionary perspective. We provide a theoretical example of SANMAO's selective pairing between amino acids and nucleosides, simulating a poly-Glycine peptide that acts as a template to build a purinic chain corresponding to the glycine's extant triplet codon GGG. Further, we discuss how SANMAO might have endorsed the formation of low-fidelity RNA's polymerized strains, well before the appearance of the accurate genetic material's transmission ensured by the current translation apparatus.
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Affiliation(s)
- Arturo Tozzi
- Center for Nonlinear Science, Department of Physics, University of North Texas, 1155 Union Circle, #311427, Denton, TX, 76203-5017, USA.
| | - Marco Mazzeo
- Erredibi Srl, Via Pazzigno 117, 80146, Naples, Italy
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5
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Parui S, Brini E, Dill KA. Computing Free Energies of Fold-Switching Proteins Using MELD x MD. J Chem Theory Comput 2023; 19:6839-6847. [PMID: 37725050 DOI: 10.1021/acs.jctc.3c00679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/21/2023]
Abstract
Some proteins are conformational switches, able to transition between relatively different conformations. To understand what drives them requires computing the free-energy difference ΔGAB between their stable states, A and B. Molecular dynamics (MD) simulations alone are often slow because they require a reaction coordinate and must sample many transitions in between. Here, we show that modeling employing limited data (MELD) x MD on known endstates A and B is accurate and efficient because it does not require passing over barriers or knowing reaction coordinates. We validate this method on two problems: (1) it gives correct relative populations of α and β conformers for small designed chameleon sequences of protein G; and (2) it correctly predicts the conformations of the C-terminal domain (CTD) of RfaH. Free-energy methods like MELD x MD can often resolve structures that confuse machine-learning (ML) methods.
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Affiliation(s)
- Sridip Parui
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York 11794, United States
| | - Emiliano Brini
- School of Chemistry and Materials Science, 85 Lomb Memorial Drive, Rochester, New York 14623, United States
| | - Ken A Dill
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York 11794, United States
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, United States
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6
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Retamal-Farfán I, González-Higueras J, Galaz-Davison P, Rivera M, Ramírez-Sarmiento CA. Exploring the structural acrobatics of fold-switching proteins using simplified structure-based models. Biophys Rev 2023; 15:787-799. [PMID: 37681096 PMCID: PMC10480104 DOI: 10.1007/s12551-023-01087-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 06/22/2023] [Indexed: 09/09/2023] Open
Abstract
Metamorphic proteins are a paradigm of the protein folding process, by encoding two or more native states, highly dissimilar in terms of their secondary, tertiary, and even quaternary structure, on a single amino acid sequence. Moreover, these proteins structurally interconvert between these native states in a reversible manner at biologically relevant timescales as a result of different environmental cues. The large-scale rearrangements experienced by these proteins, and their sometimes high mass interacting partners that trigger their metamorphosis, makes the computational and experimental study of their structural interconversion challenging. Here, we present our efforts in studying the refolding landscapes of two quintessential metamorphic proteins, RfaH and KaiB, using simplified dual-basin structure-based models (SBMs), rigorously footed on the energy landscape theory of protein folding and the principle of minimal frustration. By using coarse-grained models in which the native contacts and bonded interactions extracted from the available experimental structures of the two native states of RfaH and KaiB are merged into a single Hamiltonian, dual-basin SBM models can be generated and savvily calibrated to explore their fold-switch in a reversible manner in molecular dynamics simulations. We also describe how some of the insights offered by these simulations have driven the design of experiments and the validation of the conformational ensembles and refolding routes observed using this simple and computationally efficient models.
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Affiliation(s)
- Ignacio Retamal-Farfán
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, 7820436 Santiago, Chile
- ANID — Millennium Science Initiative Program — Millennium Institute for Integrative Biology (iBio), Santiago, Chile
| | - Jorge González-Higueras
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, 7820436 Santiago, Chile
- ANID — Millennium Science Initiative Program — Millennium Institute for Integrative Biology (iBio), Santiago, Chile
| | - Pablo Galaz-Davison
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, 7820436 Santiago, Chile
- ANID — Millennium Science Initiative Program — Millennium Institute for Integrative Biology (iBio), Santiago, Chile
| | - Maira Rivera
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, 7820436 Santiago, Chile
- Department of Chemistry, Faculty of Science, McGill University, Montreal, Quebec H3A 0B8 Canada
| | - César A. Ramírez-Sarmiento
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, 7820436 Santiago, Chile
- ANID — Millennium Science Initiative Program — Millennium Institute for Integrative Biology (iBio), Santiago, Chile
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7
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Conev A, Rigo MM, Devaurs D, Fonseca AF, Kalavadwala H, de Freitas MV, Clementi C, Zanatta G, Antunes DA, Kavraki LE. EnGens: a computational framework for generation and analysis of representative protein conformational ensembles. Brief Bioinform 2023; 24:bbad242. [PMID: 37418278 PMCID: PMC10359083 DOI: 10.1093/bib/bbad242] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 05/23/2023] [Accepted: 06/10/2023] [Indexed: 07/08/2023] Open
Abstract
Proteins are dynamic macromolecules that perform vital functions in cells. A protein structure determines its function, but this structure is not static, as proteins change their conformation to achieve various functions. Understanding the conformational landscapes of proteins is essential to understand their mechanism of action. Sets of carefully chosen conformations can summarize such complex landscapes and provide better insights into protein function than single conformations. We refer to these sets as representative conformational ensembles. Recent advances in computational methods have led to an increase in the number of available structural datasets spanning conformational landscapes. However, extracting representative conformational ensembles from such datasets is not an easy task and many methods have been developed to tackle it. Our new approach, EnGens (short for ensemble generation), collects these methods into a unified framework for generating and analyzing representative protein conformational ensembles. In this work, we: (1) provide an overview of existing methods and tools for representative protein structural ensemble generation and analysis; (2) unify existing approaches in an open-source Python package, and a portable Docker image, providing interactive visualizations within a Jupyter Notebook pipeline; (3) test our pipeline on a few canonical examples from the literature. Representative ensembles produced by EnGens can be used for many downstream tasks such as protein-ligand ensemble docking, Markov state modeling of protein dynamics and analysis of the effect of single-point mutations.
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Affiliation(s)
- Anja Conev
- Department of Computer Science, Rice University, Houston 77005, TX, USA
| | | | - Didier Devaurs
- MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | | | - Hussain Kalavadwala
- Department of Biology and Biochemistry, University of Houston, Houston 77004, TX, USA
| | | | - Cecilia Clementi
- Department of Physics, Freie Universität Berlin, Berlin 14195, Germany
| | - Geancarlo Zanatta
- Department of Biophysics, Institute of Biosciences, Federal University of Rio Grande do Sul, Porto Alegre 91501-970, Brazil
| | - Dinler Amaral Antunes
- Department of Biology and Biochemistry, University of Houston, Houston 77004, TX, USA
| | - Lydia E Kavraki
- Department of Computer Science, Rice University, Houston 77005, TX, USA
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8
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Conev A, Rigo MM, Devaurs D, Fonseca AF, Kalavadwala H, de Freitas MV, Clementi C, Zanatta G, Antunes DA, Kavraki L. EnGens: a computational framework for generation and analysis of representative protein conformational ensembles. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.24.538094. [PMID: 37163076 PMCID: PMC10168271 DOI: 10.1101/2023.04.24.538094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Proteins are dynamic macromolecules that perform vital functions in cells. A protein structure determines its function, but this structure is not static, as proteins change their conformation to achieve various functions. Understanding the conformational landscapes of proteins is essential to understand their mechanism of action. Sets of carefully chosen conformations can summarize such complex landscapes and provide better insights into protein function than single conformations. We refer to these sets as representative conformational ensembles. Recent advances in computational methods have led to an increase in number of available structural datasets spanning conformational landscapes. However, extracting representative conformational ensembles from such datasets is not an easy task and many methods have been developed to tackle it. Our new approach, EnGens (short for ensemble generation), collects these methods into a unified framework for generating and analyzing protein conformational ensembles. In this work we: (1) provide an overview of existing methods and tools for protein structural ensemble generation and analysis; (2) unify existing approaches in an open-source Python package, and a portable Docker image, providing interactive visualizations within a Jupyter Notebook pipeline; (3) test our pipeline on a few canonical examples found in the literature. Representative ensembles produced by EnGens can be used for many downstream tasks such as protein-ligand ensemble docking, Markov state modeling of protein dynamics and analysis of the effect of single-point mutations.
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9
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Jayaraman V, Toledo‐Patiño S, Noda‐García L, Laurino P. Mechanisms of protein evolution. Protein Sci 2022; 31:e4362. [PMID: 35762715 PMCID: PMC9214755 DOI: 10.1002/pro.4362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/11/2022] [Accepted: 05/14/2022] [Indexed: 11/06/2022]
Abstract
How do proteins evolve? How do changes in sequence mediate changes in protein structure, and in turn in function? This question has multiple angles, ranging from biochemistry and biophysics to evolutionary biology. This review provides a brief integrated view of some key mechanistic aspects of protein evolution. First, we explain how protein evolution is primarily driven by randomly acquired genetic mutations and selection for function, and how these mutations can even give rise to completely new folds. Then, we also comment on how phenotypic protein variability, including promiscuity, transcriptional and translational errors, may also accelerate this process, possibly via "plasticity-first" mechanisms. Finally, we highlight open questions in the field of protein evolution, with respect to the emergence of more sophisticated protein systems such as protein complexes, pathways, and the emergence of pre-LUCA enzymes.
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Affiliation(s)
- Vijay Jayaraman
- Department of Molecular Cell BiologyWeizmann Institute of ScienceRehovotIsrael
| | - Saacnicteh Toledo‐Patiño
- Protein Engineering and Evolution UnitOkinawa Institute of Science and Technology Graduate UniversityOkinawaJapan
| | - Lianet Noda‐García
- Department of Plant Pathology and Microbiology, Institute of Environmental Sciences, Robert H. Smith Faculty of Agriculture, Food and EnvironmentHebrew University of JerusalemRehovotIsrael
| | - Paola Laurino
- Protein Engineering and Evolution UnitOkinawa Institute of Science and Technology Graduate UniversityOkinawaJapan
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10
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Bhagavatula H, Sarkar A, Santra B, Das A. Scan-Find-Scan-Model: Discrete Site-Targeted Suppressor Design Strategy for Amyloid-β. ACS Chem Neurosci 2022; 13:2191-2208. [PMID: 35767676 DOI: 10.1021/acschemneuro.2c00272] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Alzheimer's disease is undoubtedly the most well-studied neurodegenerative disease. Consequently, the amyloid-β (Aβ) protein ranks at the top in terms of getting attention from the scientific community for structural property-based characterization. Even after decades of extensive research, there is existing volatility in terms of understanding and hence the effective tackling procedures against the disease that arises due to the lack of knowledge of both specific target- and site-specific drugs. Here, we develop a multidimensional approach based on the characterization of the common static-dynamic-thermodynamic trait of the monomeric protein, which efficiently identifies a small target sequence that contains an inherent tendency to misfold and consequently aggregate. The robustness of the identification of the target sequence comes with an abundance of a priori knowledge about the length and sequence of the target and hence guides toward effective designing of the target-specific drug with a very low probability of bottleneck and failure. Based on the target sequence information, we further identified a specific mutant that showed the maximum potential to act as a destabilizer of the monomeric protein as well as enormous success as an aggregation suppressor. We eventually tested the drug efficacy by estimating the extent of modulation of binding affinity existing within the fibrillar form of the Aβ protein due to a single-point mutation and hence provided a proof of concept of the entire protocol.
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Affiliation(s)
- Hasathi Bhagavatula
- Department of Biotechnology, Progressive Education Society's Modern College of Arts Science and Commerce, Shivajinagar, Pune 411005, India
| | - Archishman Sarkar
- School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja Subodh Chandra Mallick Road, Kolkata, West Bengal 700032, India
| | - Binit Santra
- Department of Chemistry, Indian Institute of Technology Kanpur, Kalyanpur, Kanpur, Uttar Pradesh 208016, India
| | - Atanu Das
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, Maharashtra 411008, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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11
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Vila JA. Proteins' Evolution upon Point Mutations. ACS OMEGA 2022; 7:14371-14376. [PMID: 35573218 PMCID: PMC9089682 DOI: 10.1021/acsomega.2c01407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 04/05/2022] [Indexed: 05/03/2023]
Abstract
As the reader must be already aware, state-of-the-art protein folding prediction methods have reached a smashing success in their goal of accurately determining the three-dimensional structures of proteins. Yet, a solution to simple problems such as the effects of protein point mutations on their (i) native conformation; (ii) marginal stability; (iii) ensemble of high-energy nativelike conformations; and (iv) metamorphism propensity and, hence, their evolvability, remains as an unsolved problem. As a plausible solution to the latter, some properties of the amide hydrogen-deuterium exchange, a highly sensitive probe of the structure, stability, and folding of proteins, are assessed from a new perspective. The preliminary results indicate that the protein marginal stability change upon point mutations provides the necessary and sufficient information to estimate, through a Boltzmann factor, the evolution of the amide hydrogen exchange protection factors and, consequently, that of the ensemble of folded conformations coexisting with the native state. This work contributes to our general understanding of the effects of point mutations on proteins and may spur significant progress in our efforts to develop methods to determine the appearance of new folds and functions accurately.
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12
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Wang Y, Zhao L, Zhou X, Zhang J, Jiang J, Dong H. Global Fold Switching of the RafH Protein: Diverse Structures with a Conserved Pathway. J Phys Chem B 2022; 126:2979-2989. [PMID: 35438983 DOI: 10.1021/acs.jpcb.1c10965] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
It is generally believed that a protein's sequence uniquely determines its structure, the basis for a protein to perform biological functions. However, as a representative metamorphic protein, RfaH can be encoded by a single amino acid sequence into two distinct native state structures. Its C-terminal domain (CTD) either takes an all-α-helical configuration to pack tightly with its N-terminal domain (NTD), or the CTD disassociates from the NTD, transforms into an all-β-barrel fold, and further attaches to the ribosome, leaving the NTD exposed to bind RNA polymerases. Therefore, the RfaH protein couples transcription and translation processes. Although previous studies have provided a preliminary understanding of its function, the full course of the conformational change of RfaH-CTD at the atomic level is elusive. We used teDA2, a feature space-based enhanced sampling protocol, to explore the transformation of RfaH-CTD. We found that it undergoes a large-scale structural rearrangement, with characteristic spectra as the fingerprint, and a global unfolding transition with a tighter and energetically moderate molten globule-like nucleus formed in between. The formation of this nucleus limits the possible intermediate conformations, facilitates the formation of secondary and tertiary structures, and thus ensures the efficiency of transformation. The key features along the transition path disclosed from this work are likely associated with the evolution of RfaH, such that encoding a single sequence into multiple folds with distinct biological functions is energetically unhindered.
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Affiliation(s)
- Yiqiao Wang
- Kuang Yaming Honors School, Nanjing University, Nanjing 210023, China.,School of Physics, National Laboratory of Solid State Microstructure, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Luyuan Zhao
- Hefei National Laboratory for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Xuejie Zhou
- Kuang Yaming Honors School, Nanjing University, Nanjing 210023, China
| | - Jian Zhang
- School of Physics, National Laboratory of Solid State Microstructure, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.,Institute for Brain Sciences, Nanjing University, Nanjing 210023, China
| | - Jun Jiang
- Hefei National Laboratory for Physical Sciences at the Microscale, Collaborative Innovation Center of Chemistry for Energy Materials, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Hao Dong
- Kuang Yaming Honors School, Nanjing University, Nanjing 210023, China.,Institute for Brain Sciences, Nanjing University, Nanjing 210023, China.,State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing 210023, China.,Engineering Research Center of Protein and Peptide Medicine of Ministry of Education, Nanjing University, Nanjing 210023, China
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13
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Tempra C, Scollo F, Pannuzzo M, Lolicato F, La Rosa C. A unifying framework for amyloid-mediated membrane damage: The lipid-chaperone hypothesis. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2022; 1870:140767. [PMID: 35144022 DOI: 10.1016/j.bbapap.2022.140767] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 01/31/2022] [Accepted: 02/01/2022] [Indexed: 12/16/2022]
Abstract
Over the past thirty years, researchers have highlighted the role played by a class of proteins or polypeptides that forms pathogenic amyloid aggregates in vivo, including i) the amyloid Aβ peptide, which is known to form senile plaques in Alzheimer's disease; ii) α-synuclein, responsible for Lewy body formation in Parkinson's disease and iii) IAPP, which is the protein component of type 2 diabetes-associated islet amyloids. These proteins, known as intrinsically disordered proteins (IDPs), are present as highly dynamic conformational ensembles. IDPs can partially (mis) fold into (dys) functional conformations and accumulate as amyloid aggregates upon interaction with other cytosolic partners such as proteins or lipid membranes. In addition, an increasing number of reports link the toxicity of amyloid proteins to their harmful effects on membrane integrity. Still, the molecular mechanism underlying the amyloidogenic proteins transfer from the aqueous environment to the hydrocarbon core of the membrane is poorly understood. This review starts with a historical overview of the toxicity models of amyloidogenic proteins to contextualize the more recent lipid-chaperone hypothesis. Then, we report the early molecular-level events in the aggregation and ion-channel pore formation of Aβ, IAPP, and α-synuclein interacting with model membranes, emphasizing the complexity of these processes due to their different spatial-temporal resolutions. Next, we underline the need for a combined experimental and computational approach, focusing on the strengths and weaknesses of the most commonly used techniques. Finally, the last two chapters highlight the crucial role of lipid-protein complexes as molecular switches among ion-channel-like formation, detergent-like, and fibril formation mechanisms and their implication in fighting amyloidogenic diseases.
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Affiliation(s)
- Carmelo Tempra
- Institute of Organic Chemistry and Biochemistry, Prague, Czech Republic
| | - Federica Scollo
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Martina Pannuzzo
- Laboratory of Nanotechnology for Precision Medicine, Fondazione Istituto Italiano di Tecnologia, Genoa, Italy
| | - Fabio Lolicato
- Heidelberg University Biochemistry Center, Heidelberg, Germany; Department of Physics, University of Helsinki, Helsinki, Finland.
| | - Carmelo La Rosa
- Dipartimento di Scienze Chimiche, Università degli Studi di Catania, Catania, Italy.
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14
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Dimer dissociation is a key energetic event in the fold-switch pathway of KaiB. Biophys J 2022; 121:943-955. [PMID: 35151633 PMCID: PMC8943816 DOI: 10.1016/j.bpj.2022.02.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 12/14/2021] [Accepted: 02/09/2022] [Indexed: 11/21/2022] Open
Abstract
Cyanobacteria possesses the simplest circadian clock, composed of three proteins that act as a phosphorylation oscillator: KaiA, KaiB, and KaiC. The timing of this oscillator is determined by the fold-switch of KaiB, a structural rearrangement of its C-terminal half that is accompanied by a change in the oligomerization state. During the day, KaiB forms a stable tetramer (gsKaiB), whereas it adopts a monomeric thioredoxin-like fold during the night (fsKaiB). Although the structures and functions of both native states are well studied, little is known about the sequence and structure determinants that control their structural interconversion. Here, we used confinement molecular dynamics (CCR-MD) and folding simulations using structure-based models to show that the dissociation of the gsKaiB dimer is a key energetic event for the fold-switch. Hydrogen-deuterium exchange mass spectrometry (HDXMS) recapitulates the local stability of protein regions reported by CCR-MD, with both approaches consistently indicating that the energy and backbone flexibility changes are solely associated with the region that fold-switches between gsKaiB and fsKaiB and that the localized regions that differentially stabilize gsKaiB also involve regions outside the dimer interface. Moreover, two mutants (R23C and R75C) previously reported to be relevant for altering the rhythmicity of the Kai clock were also studied by HDXMS. Particularly, R75C populates dimeric and monomeric states with a deuterium incorporation profile comparable to the one observed for fsKaiB, emphasizing the importance of the oligomerization state of KaiB for the fold-switch. These findings suggest that the information necessary to control the rhythmicity of the cyanobacterial biological clock is, to a great extent, encoded within the KaiB sequence.
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15
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Abstract
In the past, many intensive attempts failed to capture or underestimated the copopulated intermediate conformers from the protein folding/unfolding reaction. We report a promising approach to kinetically trap, resolve, and quantify protein conformers that evolve during unfolding in solution. We conducted acid-induced unfolding of three model proteins (cytochrome c, myoglobin, and lysozyme), and the corresponding reaction aliquots upon decreasing the pH were electrosprayed for high field asymmetric waveform ion mobility spectrometry (FAIMS) measurements. The copopulated conformers were resolved, visualized, and quantified by a two-dimensional mapping of the FAIMS output. Contrary to expectations, all the above proteins appeared metamorphic (multiple-folded conformations) at the physiological pH, and cytochrome c exhibited an unusual "conformational shuttling" before forming the molten globule state. Thus, in contrast to many previous studies, a wide variety of thermodynamically stable intermediate conformers, including compact, molten globule, and partially unfolded forms, was trapped from solution, probing the unfolding mechanism in detail.
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Affiliation(s)
- Veena Shankar Avadhani
- Department of Chemistry, Indian Institute of Science Education and Research Tirupati, Tirupati 517507, India
| | - Supratim Mondal
- Department of Chemistry, Indian Institute of Science Education and Research Tirupati, Tirupati 517507, India
| | - Shibdas Banerjee
- Department of Chemistry, Indian Institute of Science Education and Research Tirupati, Tirupati 517507, India
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16
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Zhu J, Avakyan N, Kakkis AA, Hoffnagle AM, Han K, Li Y, Zhang Z, Choi TS, Na Y, Yu CJ, Tezcan FA. Protein Assembly by Design. Chem Rev 2021; 121:13701-13796. [PMID: 34405992 PMCID: PMC9148388 DOI: 10.1021/acs.chemrev.1c00308] [Citation(s) in RCA: 112] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Proteins are nature's primary building blocks for the construction of sophisticated molecular machines and dynamic materials, ranging from protein complexes such as photosystem II and nitrogenase that drive biogeochemical cycles to cytoskeletal assemblies and muscle fibers for motion. Such natural systems have inspired extensive efforts in the rational design of artificial protein assemblies in the last two decades. As molecular building blocks, proteins are highly complex, in terms of both their three-dimensional structures and chemical compositions. To enable control over the self-assembly of such complex molecules, scientists have devised many creative strategies by combining tools and principles of experimental and computational biophysics, supramolecular chemistry, inorganic chemistry, materials science, and polymer chemistry, among others. Owing to these innovative strategies, what started as a purely structure-building exercise two decades ago has, in short order, led to artificial protein assemblies with unprecedented structures and functions and protein-based materials with unusual properties. Our goal in this review is to give an overview of this exciting and highly interdisciplinary area of research, first outlining the design strategies and tools that have been devised for controlling protein self-assembly, then describing the diverse structures of artificial protein assemblies, and finally highlighting the emergent properties and functions of these assemblies.
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Affiliation(s)
| | | | - Albert A. Kakkis
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, United States
| | - Alexander M. Hoffnagle
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, United States
| | - Kenneth Han
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, United States
| | - Yiying Li
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, United States
| | - Zhiyin Zhang
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, United States
| | - Tae Su Choi
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, United States
| | - Youjeong Na
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, United States
| | - Chung-Jui Yu
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, United States
| | - F. Akif Tezcan
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0340, United States
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17
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Dingfelder F, Macocco I, Benke S, Nettels D, Faccioli P, Schuler B. Slow Escape from a Helical Misfolded State of the Pore-Forming Toxin Cytolysin A. JACS AU 2021; 1:1217-1230. [PMID: 34467360 PMCID: PMC8397351 DOI: 10.1021/jacsau.1c00175] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Indexed: 05/12/2023]
Abstract
The pore-forming toxin cytolysin A (ClyA) is expressed as a large α-helical monomer that, upon interaction with membranes, undergoes a major conformational rearrangement into the protomer conformation, which then assembles into a cytolytic pore. Here, we investigate the folding kinetics of the ClyA monomer with single-molecule Förster resonance energy transfer spectroscopy in combination with microfluidic mixing, stopped-flow circular dichroism experiments, and molecular simulations. The complex folding process occurs over a broad range of time scales, from hundreds of nanoseconds to minutes. The very slow formation of the native state occurs from a rapidly formed and highly collapsed intermediate with large helical content and nonnative topology. Molecular dynamics simulations suggest pronounced non-native interactions as the origin of the slow escape from this deep trap in the free-energy surface, and a variational enhanced path-sampling approach enables a glimpse of the folding process that is supported by the experimental data.
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Affiliation(s)
- Fabian Dingfelder
- Department
of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Iuri Macocco
- Department
of Physics, Trento University, Via Sommarive 14, 38123 Povo (Trento), Italy
- SISSA, Via Bonomea 265, 34136 Trieste, Italy
| | - Stephan Benke
- Department
of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Daniel Nettels
- Department
of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Pietro Faccioli
- Department
of Physics, Trento University, Via Sommarive 14, 38123 Povo (Trento), Italy
- INFN-TIFPA, Via Sommarive 14, 38123 Povo (Trento), Italy
| | - Benjamin Schuler
- Department
of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
- Department
of Physics, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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18
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Abstract
The presence of metamorphism in the protein's native state is not yet fully understood. To shed light on this issue, we present an assessment, in terms of the amide hydrogen exchange protection factor, that aims to determine the possible existence of structural fluctuations in the native-state consistent with both the upper-bound marginal stability of proteins and the presence of metamorphism. The preliminary results enable us to conclude that the native-state metamorphism is, indeed, more probable than previously thought.
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Affiliation(s)
- Jorge A Vila
- IMASL-CONICET, Universidad Nacional de San Luis, Ejército de Los Andes 950, 5700 San Luis, Argentina
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19
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Gomez MV, Ruiz-Castañeda M, Nitschke P, Gschwind RM, Jiménez MA. Insights Into the Micelle-Induced β-Hairpin-to-α-Helix Transition of a LytA-Derived Peptide by Photo-CIDNP Spectroscopy. Int J Mol Sci 2021; 22:ijms22136666. [PMID: 34206372 PMCID: PMC8268221 DOI: 10.3390/ijms22136666] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 06/07/2021] [Accepted: 06/16/2021] [Indexed: 11/16/2022] Open
Abstract
A choline-binding module from pneumococcal LytA autolysin, LytA239–252, was reported to have a highly stable nativelike β-hairpin in aqueous solution, which turns into a stable amphipathic α-helix in the presence of micelles. Here, we aim to obtain insights into this DPC-micelle triggered β-hairpin-to-α-helix conformational transition using photo-CIDNP NMR experiments. Our results illustrate the dependency between photo-CIDNP phenomena and the light intensity in the sample volume, showing that the use of smaller-diameter (2.5 mm) NMR tubes instead of the conventional 5 mm ones enables more efficient illumination for our laser-diode light setup. Photo-CIDNP experiments reveal different solvent accessibility for the two tyrosine residues, Y249 and Y250, the latter being less accessible to the solvent. The cross-polarization effects of these two tyrosine residues of LytA239–252 allow for deeper insights and evidence their different behavior, showing that the Y250 aromatic side chain is involved in a stronger interaction with DPC micelles than Y249 is. These results can be interpreted in terms of the DPC micelle disrupting the aromatic stacking between W241 and Y250 present in the nativelike β-hairpin, hence initiating conversion towards the α-helix structure. Our photo-CIDNP methodology represents a powerful tool for observing residue-level information in switch peptides that is difficult to obtain by other spectroscopic techniques.
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Affiliation(s)
- M. Victoria Gomez
- IRICA, Department of Inorganic, Organic and Biochemistry, Faculty of Chemical Sciences and Technologies, Universidad de Castilla-La Mancha (UCLM), Av. Camilo José Cela 10, 13071 Ciudad Real, Spain;
- Correspondence: (M.V.G.); (M.A.J.)
| | - Margarita Ruiz-Castañeda
- IRICA, Department of Inorganic, Organic and Biochemistry, Faculty of Chemical Sciences and Technologies, Universidad de Castilla-La Mancha (UCLM), Av. Camilo José Cela 10, 13071 Ciudad Real, Spain;
| | - Philipp Nitschke
- Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany; (P.N.); (R.M.G.)
| | - Ruth M. Gschwind
- Institute of Organic Chemistry, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany; (P.N.); (R.M.G.)
| | - M. Angeles Jiménez
- Departamento de Química-Física Biológica, Instituto de Química Física Rocasolano (IQFR-CSIC), Serrano 119, 28006 Madrid, Spain
- Correspondence: (M.V.G.); (M.A.J.)
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20
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Kolodny R, Nepomnyachiy S, Tawfik DS, Ben-Tal N. Bridging Themes: Short Protein Segments Found in Different Architectures. Mol Biol Evol 2021; 38:2191-2208. [PMID: 33502503 PMCID: PMC8136508 DOI: 10.1093/molbev/msab017] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The vast majority of theoretically possible polypeptide chains do not fold, let alone confer function. Hence, protein evolution from preexisting building blocks has clear potential advantages over ab initio emergence from random sequences. In support of this view, sequence similarities between different proteins is generally indicative of common ancestry, and we collectively refer to such homologous sequences as "themes." At the domain level, sequence homology is routinely detected. However, short themes which are segments, or fragments of intact domains, are particularly interesting because they may provide hints about the emergence of domains, as opposed to divergence of preexisting domains, or their mixing-and-matching to form multi-domain proteins. Here we identified 525 representative short themes, comprising 20-80 residues that are unexpectedly shared between domains considered to have emerged independently. Among these "bridging themes" are ones shared between the most ancient domains, for example, Rossmann, P-loop NTPase, TIM-barrel, flavodoxin, and ferredoxin-like. We elaborate on several particularly interesting cases, where the bridging themes mediate ligand binding. Ligand binding may have contributed to the stability and the plasticity of these building blocks, and to their ability to invade preexisting domains or serve as starting points for completely new domains.
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Affiliation(s)
- Rachel Kolodny
- Department of Computer Science, University of Haifa, Haifa, Israel
| | | | - Dan S Tawfik
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Nir Ben-Tal
- George S. Wise Faculty of Life Sciences, Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel Aviv, Israel
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21
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Madhurima K, Nandi B, Sekhar A. Metamorphic proteins: the Janus proteins of structural biology. Open Biol 2021; 11:210012. [PMID: 33878950 PMCID: PMC8059507 DOI: 10.1098/rsob.210012] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The structural paradigm that the sequence of a protein encodes for a unique three-dimensional native fold does not acknowledge the intrinsic plasticity encapsulated in conformational free energy landscapes. Metamorphic proteins are a recently discovered class of biomolecules that illustrate this plasticity by folding into at least two distinct native state structures of comparable stability in the absence of ligands or cofactors to facilitate fold-switching. The expanding list of metamorphic proteins clearly shows that these proteins are not mere aberrations in protein evolution, but may have actually been a consequence of distinctive patterns in selection pressure such as those found in virus–host co-evolution. In this review, we describe the structure–function relationships observed in well-studied metamorphic protein systems, with specific focus on how functional residues are sequestered or exposed in the two folds of the protein. We also discuss the implications of metamorphosis for protein evolution and the efforts that are underway to predict metamorphic systems from sequence properties alone.
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Affiliation(s)
- Kulkarni Madhurima
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
| | - Bodhisatwa Nandi
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
| | - Ashok Sekhar
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India
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22
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Tsai WC, Aleem AM, Whittington C, Cortopassi WA, Kalyanaraman C, Baroz A, Iavarone AT, Skrzypczak-Jankun E, Jacobson MP, Offenbacher AR, Holman T. Mutagenesis, Hydrogen-Deuterium Exchange, and Molecular Docking Investigations Establish the Dimeric Interface of Human Platelet-Type 12-Lipoxygenase. Biochemistry 2021; 60:802-812. [PMID: 33635645 DOI: 10.1021/acs.biochem.1c00053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
It was previously shown that human platelet 12S-lipoxygenase (h12-LOX) exists as a dimer; however, the specific structure is unknown. In this study, we create a model of the dimer through a combination of computational methods, experimental mutagenesis, and hydrogen-deuterium exchange (HDX) investigations. Initially, Leu183 and Leu187 were replaced by negatively charged glutamate residues and neighboring aromatic residues were replaced with alanine residues (F174A/W176A/L183E/L187E/Y191A). This quintuple mutant disrupted both the hydrophobic and π-π interactions, generating an h12-LOX monomer. To refine the determinants for dimer formation further, the L183E/L187E mutant was generated and the equilibrium shifted mostly toward the monomer. We then submitted the predicted monomeric structure to protein-protein docking to create a model of the dimeric complex. A total of nine of the top 10 most energetically favorable docking conformations predict a TOP-to-TOP dimeric arrangement of h12-LOX, with the α-helices containing a Leu-rich region (L172, L183, L187, and L194), corroborating our experimental results showing the importance of these hydrophobic interactions for dimerization. This model was supported by HDX investigations that demonstrated the stabilization of four, non-overlapping peptides within helix α2 of the TOP subdomain for wt-h12-LOX, consistent with the dimer interface. Most importantly, our data reveal that the dimer and monomer of h12-LOX have distinct biochemical properties, suggesting that the structural changes due to dimerization have allosteric effects on active site catalysis and inhibitor binding.
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Affiliation(s)
- Wan-Chen Tsai
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California 95064, United States
| | - Ansari Mukhtar Aleem
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California 95064, United States
| | - Chris Whittington
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
| | - Wilian A Cortopassi
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco, San Francisco, California 94143, United States
| | - Chakrapani Kalyanaraman
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco, San Francisco, California 94143, United States
| | - Angel Baroz
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California 95064, United States
| | - Anthony T Iavarone
- QB3/Chemistry Mass Spectrometry Facility, University of California, Berkeley, Berkeley, California 94720, United States
| | - Ewa Skrzypczak-Jankun
- Department of Urology, University of Toledo, Health Science Campus, Toledo, Ohio 43614, United States
| | - Matthew P Jacobson
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco, San Francisco, California 94143, United States
| | - Adam R Offenbacher
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858, United States
| | - Theodore Holman
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California 95064, United States
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23
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Seifi B, Wallin S. The C-terminal domain of transcription factor RfaH: Folding, fold switching and energy landscape. Biopolymers 2021; 112:e23420. [PMID: 33521926 DOI: 10.1002/bip.23420] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 01/12/2021] [Accepted: 01/14/2021] [Indexed: 12/27/2022]
Abstract
We simulate the folding and fold switching of the C-terminal domain (CTD) of the transcription factor RfaH using an all-atom physics-based model augmented with a dual-basin structure-based potential energy term. We show that this hybrid model captures the essential thermodynamic behavior of this metamorphic domain, that is, a change in the global free energy minimum from an α-helical hairpin to a 5-stranded β-barrel upon the dissociation of the CTD from the rest of the protein. Using Monte Carlo sampling techniques, we then analyze the energy landscape of the CTD in terms of progress variables for folding toward the two folds. We find that, below the folding transition, the energy landscape is characterized by a single, dominant funnel to the native β-barrel structure. The absence of a deep funnel to the α-helical hairpin state reflects a negligible population of this fold for the isolated CTD. We observe, however, a higher α-helix structure content in the unfolded state compared to results from a similar but fold switch-incompetent version of our model. Moreover, in folding simulations started from an extended chain conformation we find transiently formed α-helical structure, occurring early in the process and disappearing as the chain progresses toward the thermally stable β-barrel state.
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Affiliation(s)
- Bahman Seifi
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St Johns, Canada
| | - Stefan Wallin
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St Johns, Canada
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24
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Searching protein space for ancient sub-domain segments. Curr Opin Struct Biol 2021; 68:105-112. [PMID: 33476896 DOI: 10.1016/j.sbi.2020.11.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 11/29/2020] [Indexed: 01/08/2023]
Abstract
Evolutionary processes that formed the current protein universe left their traces, among them homologous segments that recur, or are 'reused,' in multiple proteins. These reused segments, called 'themes,' can be found at various scales, the best known of which is the domain. Yet, recent studies have begun to focus on the evolutionary insights that can be derived from sub-domain-scale themes, which are candidates for traces of more ancient events. Characterizing these may provide clues to the emergence of domains. Particularly interesting are themes that are reused across dissimilar contexts, that is, where the rest of the protein domain differs. We survey computational studies identifying reused themes within different contexts at the sub-domain level.
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25
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Dishman AF, Tyler RC, Fox JC, Kleist AB, Prehoda KE, Babu MM, Peterson FC, Volkman BF. Evolution of fold switching in a metamorphic protein. Science 2021; 371:86-90. [PMID: 33384377 PMCID: PMC8017559 DOI: 10.1126/science.abd8700] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 11/11/2020] [Indexed: 12/14/2022]
Abstract
Metamorphic proteins switch between different folds, defying the protein folding paradigm. It is unclear how fold switching arises during evolution. With ancestral reconstruction and nuclear magnetic resonance, we studied the evolution of the metamorphic human protein XCL1, which has two distinct folds with different functions, making it an unusual member of the chemokine family, whose members generally adopt one conserved fold. XCL1 evolved from an ancestor with the chemokine fold. Evolution of a dimer interface, changes in structural constraints and molecular strain, and alteration of intramolecular protein contacts drove the evolution of metamorphosis. Then, XCL1 likely evolved to preferentially populate the noncanonical fold before reaching its modern-day near-equal population of folds. These discoveries illuminate how one sequence has evolved to encode multiple structures, revealing principles for protein design and engineering.
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Affiliation(s)
- Acacia F Dishman
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, USA
- Medical Scientist Training Program, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Robert C Tyler
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Jamie C Fox
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Andrew B Kleist
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, USA
- Medical Scientist Training Program, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Kenneth E Prehoda
- Institute of Molecular Biology, Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR, USA
| | - M Madan Babu
- MRC Laboratory of Molecular Biology, Cambridge, UK
- Department of Structural Biology and Center for Data Driven Discovery, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Francis C Peterson
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Brian F Volkman
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, USA.
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26
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Functional and Structural Variation among Sticholysins, Pore-Forming Proteins from the Sea Anemone Stichodactyla helianthus. Int J Mol Sci 2020; 21:ijms21238915. [PMID: 33255441 PMCID: PMC7727798 DOI: 10.3390/ijms21238915] [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: 10/19/2020] [Revised: 11/19/2020] [Accepted: 11/20/2020] [Indexed: 12/15/2022] Open
Abstract
Venoms constitute complex mixtures of many different molecules arising from evolution in processes driven by continuous prey-predator interactions. One of the most common compounds in these venomous cocktails are pore-forming proteins, a family of toxins whose activity relies on the disruption of the plasmatic membranes by forming pores. The venom of sea anemones, belonging to the oldest lineage of venomous animals, contains a large amount of a characteristic group of pore-forming proteins known as actinoporins. They bind specifically to sphingomyelin-containing membranes and suffer a conformational metamorphosis that drives them to make pores. This event usually leads cells to death by osmotic shock. Sticholysins are the actinoporins produced by Stichodactyla helianthus. Three different isotoxins are known: Sticholysins I, II, and III. They share very similar amino acid sequence and three-dimensional structure but display different behavior in terms of lytic activity and ability to interact with cholesterol, an important lipid component of vertebrate membranes. In addition, sticholysins can act in synergy when exerting their toxin action. The subtle, but important, molecular nuances that explain their different behavior are described and discussed throughout the text. Improving our knowledge about sticholysins behavior is important for eventually developing them into biotechnological tools.
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27
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Amyloidogenic Intrinsically Disordered Proteins: New Insights into Their Self-Assembly and Their Interaction with Membranes. Life (Basel) 2020; 10:life10080144. [PMID: 32784399 PMCID: PMC7459996 DOI: 10.3390/life10080144] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 08/02/2020] [Accepted: 08/06/2020] [Indexed: 12/21/2022] Open
Abstract
Aβ, IAPP, α-synuclein, and prion proteins belong to the amyloidogenic intrinsically disordered proteins’ family; indeed, they lack well defined secondary and tertiary structures. It is generally acknowledged that they are involved, respectively, in Alzheimer’s, Type II Diabetes Mellitus, Parkinson’s, and Creutzfeldt–Jakob’s diseases. The molecular mechanism of toxicity is under intense debate, as many hypotheses concerning the involvement of the amyloid and the toxic oligomers have been proposed. However, the main role is represented by the interplay of protein and the cell membrane. Thus, the understanding of the interaction mechanism at the molecular level is crucial to shed light on the dynamics driving this phenomenon. There are plenty of factors influencing the interaction as mentioned above, however, the overall view is made trickier by the apparent irreproducibility and inconsistency of the data reported in the literature. Here, we contextualized this topic in a historical, and even more importantly, in a future perspective. We introduce two novel insights: the chemical equilibrium, always established in the aqueous phase between the free and the membrane phospholipids, as mediators of protein-transport into the core of the bilayer, and the symmetry-breaking of oligomeric aggregates forming an alternating array of partially ordered and disordered monomers.
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28
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Liu H, Jeffery CJ. Moonlighting Proteins in the Fuzzy Logic of Cellular Metabolism. Molecules 2020; 25:molecules25153440. [PMID: 32751110 PMCID: PMC7435893 DOI: 10.3390/molecules25153440] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/09/2020] [Accepted: 07/23/2020] [Indexed: 12/15/2022] Open
Abstract
The numerous interconnected biochemical pathways that make up the metabolism of a living cell comprise a fuzzy logic system because of its high level of complexity and our inability to fully understand, predict, and model the many activities, how they interact, and their regulation. Each cell contains thousands of proteins with changing levels of expression, levels of activity, and patterns of interactions. Adding more layers of complexity is the number of proteins that have multiple functions. Moonlighting proteins include a wide variety of proteins where two or more functions are performed by one polypeptide chain. In this article, we discuss examples of proteins with variable functions that contribute to the fuzziness of cellular metabolism.
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Affiliation(s)
- Haipeng Liu
- Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, 900 South Ashland Avenue, Chicago, IL 60607, USA;
| | - Constance J. Jeffery
- Department of Biological Sciences, University of Illinois at Chicago, 900 South Ashland Avenue, Chicago, IL 60607, USA
- Correspondence: ; Tel.: +1-312-996-3168
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29
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Liebau J, Tersa M, Trastoy B, Patrick J, Rodrigo-Unzueta A, Corzana F, Sparrman T, Guerin ME, Mäler L. Unveiling the activation dynamics of a fold-switch bacterial glycosyltransferase by 19F NMR. J Biol Chem 2020; 295:9868-9878. [PMID: 32434931 PMCID: PMC7380196 DOI: 10.1074/jbc.ra120.014162] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 05/19/2020] [Indexed: 11/06/2022] Open
Abstract
Fold-switch pathways remodel the secondary structure topology of proteins in response to the cellular environment. It is a major challenge to understand the dynamics of these folding processes. Here, we conducted an in-depth analysis of the α-helix–to–β-strand and β-strand–to–α-helix transitions and domain motions displayed by the essential mannosyltransferase PimA from mycobacteria. Using 19F NMR, we identified four functionally relevant states of PimA that coexist in dynamic equilibria on millisecond-to-second timescales in solution. We discovered that fold-switching is a slow process, on the order of seconds, whereas domain motions occur simultaneously but are substantially faster, on the order of milliseconds. Strikingly, the addition of substrate accelerated the fold-switching dynamics of PimA. We propose a model in which the fold-switching dynamics constitute a mechanism for PimA activation.
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Affiliation(s)
- Jobst Liebau
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Montse Tersa
- Structural Biology Unit, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Derio, Spain
| | - Beatriz Trastoy
- Structural Biology Unit, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Derio, Spain
| | - Joan Patrick
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Ane Rodrigo-Unzueta
- Departamento de Bioquímica and Instituto Biofisika, Consejo Superior de Investigaciones Científicas-Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC, UPV/EHU), Bizkaia, Spain
| | - Francisco Corzana
- Departamento de Química, Centro de Investigación en Síntesis Química, Universidad de La Rioja, Logroño, Spain
| | | | - Marcelo E Guerin
- Structural Biology Unit, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Derio, Spain .,Departamento de Bioquímica and Instituto Biofisika, Consejo Superior de Investigaciones Científicas-Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC, UPV/EHU), Bizkaia, Spain.,IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Lena Mäler
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden .,Department of Chemistry, Umeå University, Umeå, Sweden
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30
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Directional conformer exchange in dihydrofolate reductase revealed by single-molecule nanopore recordings. Nat Chem 2020; 12:481-488. [DOI: 10.1038/s41557-020-0437-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 02/10/2020] [Indexed: 12/18/2022]
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31
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Tenorio CA, Longo LM, Parker JB, Lee J, Blaber M. Ab initio folding of a trefoil-fold motif reveals structural similarity with a β-propeller blade motif. Protein Sci 2020; 29:1172-1185. [PMID: 32142181 DOI: 10.1002/pro.3850] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 03/01/2020] [Accepted: 03/03/2020] [Indexed: 01/05/2023]
Abstract
Many protein architectures exhibit evidence of internal rotational symmetry postulated to be the result of gene duplication/fusion events involving a primordial polypeptide motif. A common feature of such structures is a domain-swapped arrangement at the interface of the N- and C-termini motifs and postulated to provide cooperative interactions that promote folding and stability. De novo designed symmetric protein architectures have demonstrated an ability to accommodate circular permutation of the N- and C-termini in the overall architecture; however, the folding requirement of the primordial motif is poorly understood, and tolerance to circular permutation is essentially unknown. The β-trefoil protein fold is a threefold-symmetric architecture where the repeating ~42-mer "trefoil-fold" motif assembles via a domain-swapped arrangement. The trefoil-fold structure in isolation exposes considerable hydrophobic area that is otherwise buried in the intact β-trefoil trimeric assembly. The trefoil-fold sequence is not predicted to adopt the trefoil-fold architecture in ab initio folding studies; rather, the predicted fold is closely related to a compact "blade" motif from the β-propeller architecture. Expression of a trefoil-fold sequence and circular permutants shows that only the wild-type N-terminal motif definition yields an intact β-trefoil trimeric assembly, while permutants yield monomers. The results elucidate the folding requirements of the primordial trefoil-fold motif, and also suggest that this motif may sample a compact conformation that limits hydrophobic residue exposure, contains key trefoil-fold structural features, but is more structurally homologous to a β-propeller blade motif.
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Affiliation(s)
- Connie A Tenorio
- Department of Biomedical Sciences, Florida State University, Tallahassee, Florida, USA
| | - Liam M Longo
- Department of Biomedical Sciences, Florida State University, Tallahassee, Florida, USA
| | - Joseph B Parker
- Department of Biomedical Sciences, Florida State University, Tallahassee, Florida, USA
| | - Jihun Lee
- Department of Biomedical Sciences, Florida State University, Tallahassee, Florida, USA
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32
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Sastre DE, Basso LGM, Trastoy B, Cifuente JO, Contreras X, Gueiros-Filho F, de Mendoza D, Navarro MVAS, Guerin ME. Membrane fluidity adjusts the insertion of the transacylase PlsX to regulate phospholipid biosynthesis in Gram-positive bacteria. J Biol Chem 2019; 295:2136-2147. [PMID: 31796629 DOI: 10.1074/jbc.ra119.011122] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 11/19/2019] [Indexed: 12/24/2022] Open
Abstract
PlsX plays a central role in the coordination of fatty acid and phospholipid biosynthesis in Gram-positive bacteria. PlsX is a peripheral membrane acyltransferase that catalyzes the conversion of acyl-ACP to acyl-phosphate, which is in turn utilized by the polytopic membrane acyltransferase PlsY on the pathway of bacterial phospholipid biosynthesis. We have recently studied the interaction between PlsX and membrane phospholipids in vivo and in vitro, and observed that membrane association is necessary for the efficient transfer of acyl-phosphate to PlsY. However, understanding the molecular basis of such a channeling mechanism remains a major challenge. Here, we disentangle the binding and insertion events of the enzyme to the membrane, and the subsequent catalysis. We show that PlsX membrane binding is a process mostly mediated by phospholipid charge, whereas fatty acid saturation and membrane fluidity remarkably influence the membrane insertion step. Strikingly, the PlsXL254E mutant, whose biological functionality was severely compromised in vivo but remains catalytically active in vitro, was able to superficially bind to phospholipid vesicles, nevertheless, it loses the insertion capacity, strongly supporting the importance of membrane insertion in acyl-phosphate delivery. We propose a mechanism in which membrane fluidity governs the insertion of PlsX and thus regulates the biosynthesis of phospholipids in Gram-positive bacteria. This model may be operational in other peripheral membrane proteins with an unprecedented impact in drug discovery/development strategies.
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Affiliation(s)
- Diego E Sastre
- Grupo de Biofísica Molecular "Sergio Mascarenhas," Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, São Paulo, Brasil.
| | - Luis G M Basso
- Departamento de Física, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil
| | - Beatriz Trastoy
- Structural Biology Unit, CIC bioGUNE Technological Park of Bizkaia, Derio, Vizcaya, Spain
| | - Javier O Cifuente
- Structural Biology Unit, CIC bioGUNE Technological Park of Bizkaia, Derio, Vizcaya, Spain
| | - Xabier Contreras
- IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain; Instituto Biofisika, Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea (CSIC,UPV/EHU), Barrio Sarriena s/n, Leioa, 48940 Bizkaia, Spain; Departamento de Bioquímica, Universidad del País Vasco, Leioa, 48940 Bizkaia, Spain
| | - Frederico Gueiros-Filho
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, São Paulo, Brasil
| | - Diego de Mendoza
- Instituto de Biología Molecular y Celular de Rosario (IBR), Rosario, Santa Fe, Argentina
| | - Marcos V A S Navarro
- Grupo de Biofísica Molecular "Sergio Mascarenhas," Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, São Paulo, Brasil
| | - Marcelo E Guerin
- Structural Biology Unit, CIC bioGUNE Technological Park of Bizkaia, Derio, Vizcaya, Spain; IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain.
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33
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Galaz-Davison P, Molina JA, Silletti S, Komives EA, Knauer SH, Artsimovitch I, Ramírez-Sarmiento CA. Differential Local Stability Governs the Metamorphic Fold Switch of Bacterial Virulence Factor RfaH. Biophys J 2019; 118:96-104. [PMID: 31810657 DOI: 10.1016/j.bpj.2019.11.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 10/21/2019] [Accepted: 11/14/2019] [Indexed: 12/15/2022] Open
Abstract
RfaH, a two-domain protein from a universally conserved NusG/Spt5 family of regulators, is required for the transcription and translation of long virulence and conjugation operons in many Gram-negative bacterial pathogens. Escherichia coli RfaH action is controlled by a unique large-scale structural rearrangement triggered by recruitment to transcription elongation complexes through a specific DNA element. Upon recruitment, the C-terminal domain of RfaH refolds from an α-hairpin, which is bound to RNA polymerase binding site within the N-terminal domain, into an unbound β-barrel that interacts with the ribosome. Although structures of the autoinhibited (α-hairpin) and active (β-barrel) states and plausible refolding pathways have been reported, how this reversible switch is encoded within RfaH sequence and structure is poorly understood. Here, we combined hydrogen-deuterium exchange measurements by mass spectrometry and nuclear magnetic resonance with molecular dynamics to evaluate the differential local stability between both RfaH folds. Deuteron incorporation reveals that the tip of the C-terminal hairpin (residues 125-145) is stably folded in the autoinhibited state (∼20% deuteron incorporation), whereas the rest of this domain is highly flexible (>40% deuteron incorporation), and its flexibility only decreases in the β-folded state. Computationally predicted ΔG agree with these results by displaying similar anisotropic stability within the tip of the α-hairpin and on neighboring N-terminal domain residues. Remarkably, the β-folded state shows comparable structural flexibility than nonmetamorphic homologs. Our findings provide information critical for understanding the metamorphic behavior of RfaH and other chameleon proteins and for devising targeted strategies to combat bacterial infections.
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Affiliation(s)
- Pablo Galaz-Davison
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - José Alejandro Molina
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Steve Silletti
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California
| | - Elizabeth A Komives
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California
| | - Stefan H Knauer
- Lehrstuhl Biopolymere, Universität Bayreuth, Bayreuth, Germany
| | - Irina Artsimovitch
- Department of Microbiology and The Center for RNA Biology, The Ohio State University, Columbus, Ohio.
| | - César A Ramírez-Sarmiento
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile.
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34
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Zamora-Carreras H, Maestro B, Sanz JM, Jiménez MA. Turncoat Polypeptides: We Adapt to Our Environment. Chembiochem 2019; 21:432-441. [PMID: 31456307 DOI: 10.1002/cbic.201900446] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Indexed: 01/25/2023]
Abstract
A common interpretation of Anfinsen's hypothesis states that one amino acid sequence should fold into a single, native, ordered state, or a highly similar set thereof, coinciding with the global minimum in the folding-energy landscape, which, in turn, is responsible for the function of the protein. However, this classical view is challenged by many proteins and peptide sequences, which can adopt exchangeable, significantly dissimilar conformations that even fulfill different biological roles. The similarities and differences of concepts related to these proteins, mainly chameleon sequences, metamorphic proteins, and switch peptides, which are all denoted herein "turncoat" polypeptides, are reviewed. As well as adding a twist to the conventional view of protein folding, the lack of structural definition adds clear versatility to the activity of proteins and can be used as a tool for protein design and further application in biotechnology and biomedicine.
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Affiliation(s)
- Héctor Zamora-Carreras
- Instituto de Química-Física Rocasolano (IQFR), Consejo Superior de Investigaciones Científicas (CSIC), Serrano 119, 28006, Madrid, Spain
| | - Beatriz Maestro
- Centro de Investigaciones Biológicas (CIB), Consejo Superior de Investigaciones Científicas (CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Jesús M Sanz
- Centro de Investigaciones Biológicas (CIB), Consejo Superior de Investigaciones Científicas (CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Av. Monforte de Lemos, 3-5. Pabellón, 28029, Madrid, Spain
| | - M Angeles Jiménez
- Instituto de Química-Física Rocasolano (IQFR), Consejo Superior de Investigaciones Científicas (CSIC), Serrano 119, 28006, Madrid, Spain
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35
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Pore-Forming Proteins from Cnidarians and Arachnids as Potential Biotechnological Tools. Toxins (Basel) 2019; 11:toxins11060370. [PMID: 31242582 PMCID: PMC6628452 DOI: 10.3390/toxins11060370] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 06/18/2019] [Accepted: 06/21/2019] [Indexed: 12/31/2022] Open
Abstract
Animal venoms are complex mixtures of highly specialized toxic molecules. Cnidarians and arachnids produce pore-forming proteins (PFPs) directed against the plasma membrane of their target cells. Among PFPs from cnidarians, actinoporins stand out for their small size and molecular simplicity. While native actinoporins require only sphingomyelin for membrane binding, engineered chimeras containing a recognition antibody-derived domain fused to an actinoporin isoform can nonetheless serve as highly specific immunotoxins. Examples of such constructs targeted against malignant cells have been already reported. However, PFPs from arachnid venoms are less well-studied from a structural and functional point of view. Spiders from the Latrodectus genus are professional insect hunters that, as part of their toxic arsenal, produce large PFPs known as latrotoxins. Interestingly, some latrotoxins have been identified as potent and highly-specific insecticides. Given the proteinaceous nature of these toxins, their promising future use as efficient bioinsecticides is discussed throughout this Perspective. Protein engineering and large-scale recombinant production are critical steps for the use of these PFPs as tools to control agriculturally important insect pests. In summary, both families of PFPs, from Cnidaria and Arachnida, appear to be molecules with promising biotechnological applications.
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36
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Palacios-Ortega J, García-Linares S, Rivera-de-Torre E, Gavilanes JG, Martínez-Del-Pozo Á, Slotte JP. Sticholysin, Sphingomyelin, and Cholesterol: A Closer Look at a Tripartite Interaction. Biophys J 2019; 116:2253-2265. [PMID: 31146924 DOI: 10.1016/j.bpj.2019.05.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 05/05/2019] [Accepted: 05/10/2019] [Indexed: 02/06/2023] Open
Abstract
Actinoporins are a group of soluble toxic proteins that bind to membranes containing sphingomyelin (SM) and oligomerize to form pores. Sticholysin II (StnII) is a member of the actinoporin family produced by Stichodactyla helianthus. Cholesterol (Chol) is known to enhance the activity of StnII. However, the molecular mechanisms behind this activation have remained obscure, although the activation is not Chol specific but rather sterol specific. To further explore how bilayer lipids affect or are affected by StnII, we have used a multiprobe approach (fluorescent analogs of both Chol and SM) in combination with a series of StnII tryptophan (Trp) mutants to study StnII/bilayer interactions. First, we compared StnII bilayer permeabilization in the presence of Chol or oleoyl-ceramide (OCer). The comparison was done because both Chol and OCer have a 1-hydroxyl, which helps to orient the molecule in the bilayer (although OCer has additional polar functional groups). Both Chol and OCer also have increased affinity for SM, which StnII may recognize. However, our results show that only Chol was able to activate StnII-induced bilayer permeabilization; OCer failed to activate it. To further examine possible Chol/StnII interactions, we measured Förster resonance energy transfer between Trp in StnII and cholestatrienol, a fluorescent analog of Chol. We could show higher Förster resonance energy transfer efficiency between cholestatrienol and Trps in position 100 and 114 of StnII when compared to three other Trp positions further away from the bilayer binding region of StnII. Taken together, our results suggest that StnII was able to attract Chol to its vicinity, maybe by showing affinity for Chol. SM interactions are known to be important for StnII binding to bilayers, and Chol is known to facilitate subsequent permeabilization of the bilayers by StnII. Our results help to better understand the role of these important membrane lipids for the bilayer properties of StnII.
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Affiliation(s)
- Juan Palacios-Ortega
- Departamento de Bioquímica y Biología Molecular, Universidad Complutense, Madrid, Spain; Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - Sara García-Linares
- Departamento de Bioquímica y Biología Molecular, Universidad Complutense, Madrid, Spain
| | | | - José G Gavilanes
- Departamento de Bioquímica y Biología Molecular, Universidad Complutense, Madrid, Spain
| | | | - J Peter Slotte
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland.
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37
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Risso VA, Ermácora MR. Equilibrium partially folded states of B. licheniformis[Formula: see text]-lactamase. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2019; 48:341-348. [PMID: 30929094 DOI: 10.1007/s00249-019-01361-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Revised: 02/14/2019] [Accepted: 03/15/2019] [Indexed: 10/27/2022]
Abstract
[Formula: see text]-Lactamases (penicillinases) facilitate bacterial resistance to antibiotics and are excellent theoretical and experimental models in protein structure, dynamics and evolution. Bacillus licheniformis exo-small penicillinase (ESP) is a Class A [Formula: see text]-lactamase with three tryptophan residues located one in each of its two domains and one in the interface between domains. The conformational landscape of three well-characterized ESP Trp[Formula: see text]Phe mutants was characterized in equilibrium unfolding experiments by measuring tryptophan fluorescence, far-UV CD, activity, hydrodynamic radius, and limited proteolysis. The Trp[Formula: see text]Phe substitutions had little impact on the native conformation, but changed the properties of the partially folded states populated at equilibrium. The results were interpreted in the framework of modern theories of protein folding.
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Affiliation(s)
- Valeria A Risso
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Roque Sáenz Peña 352, B1876BXD, Bernal, Buenos Aires, Argentina.,Departamento de Quimica Fisica, Facultad de Ciencias, University of Granada, 18071, Granada, Spain
| | - Mario R Ermácora
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Roque Sáenz Peña 352, B1876BXD, Bernal, Buenos Aires, Argentina. .,Instituto Multidisciplinario de Biología Celular, Conicet-CIC-UNLP, Calle 526 y Camino General Belgrano, B1906APO, La Plata, Buenos Aires, Argentina.
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38
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Chen X, Zhu S, Zhenin M, Xu W, Bose SJ, Wong MPF, Leung GPH, Senderowitz H, Chen JH. A defective flexible loop contributes to the processing and gating defects of the predominant cystic fibrosis-causing mutation. FASEB J 2019; 33:5126-5142. [PMID: 30668920 DOI: 10.1096/fj.201801218rr] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
People with the genetic disease cystic fibrosis (CF) often carry a deletion mutation ΔF508 on the gene encoding the CF transmembrane conductance regulator (CFTR) Cl- channel. This mutation greatly reduces the CFTR maturation process and slows the channel opening rate. Here, we investigate whether residues near F508 contribute to these defects in ΔF508-CFTR. Most deletion mutations, but not alanine substitutions, of individual residues from positions 503 to 513 impaired CFTR maturation. Interestingly, only protein processing of ΔY512-CFTR, like that of ΔF508-CFTR, was greatly improved by low-temperature culture at 27°C or small-molecule corrector C18. The 2 mutant Cl- channels were equally slow to open, suggesting that they may share common structural flaws. Studies on the H3-H4 loop that links residues F508 and Y512 demonstrate that G509A/V510G mutations, moving G509 1 position backward in the loop, markedly enhanced ΔF508-CFTR maturation and opening rate while promoting protein stability and persistence of the H3 helix in ΔF508 nucleotide-binding domain 1. Moreover, V510A/S511A mutations noticeably increased ΔY512-CFTR maturation at 27°C and its opening rate. Thus, loop abnormalities may contribute to ΔF508- and ΔY512-CFTR defects. Importantly, correcting defects from G509 displacement in ΔF508-CFTR may offer a new avenue for drug discovery and CF treatments.-Chen, X., Zhu, S., Zhenin, M., Xu, W., Bose, S. J., Wong, M. P.-F., Leung, G. P. H., Senderowitz, H., Chen, J.-H. A defective flexible loop contributes to the processing and gating defects of the predominant cystic fibrosis-causing mutation.
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Affiliation(s)
- Xinying Chen
- School of Biomedical Sciences, University of Hong Kong, Hong Kong.,The University of Hong Kong Shenzhen Institute of Research and Innovation, Shenzhen, China
| | - Siyu Zhu
- School of Biomedical Sciences, University of Hong Kong, Hong Kong.,The University of Hong Kong Shenzhen Institute of Research and Innovation, Shenzhen, China
| | - Michael Zhenin
- Department of Chemistry, Bar Ilan University, Ramat-Gan, Israel
| | - Weiyi Xu
- School of Biomedical Sciences, University of Hong Kong, Hong Kong.,The University of Hong Kong Shenzhen Institute of Research and Innovation, Shenzhen, China
| | - Samuel J Bose
- School of Physiology, Pharmacology, and Neuroscience, University of Bristol, Bristol, United Kingdom; and
| | - Molly Pik-Fan Wong
- School of Biomedical Sciences, University of Hong Kong, Hong Kong.,The University of Hong Kong Shenzhen Institute of Research and Innovation, Shenzhen, China
| | - George P H Leung
- Department of Pharmacology and Pharmacy, University of Hong Kong, Hong Kong, China
| | | | - Jeng-Haur Chen
- School of Biomedical Sciences, University of Hong Kong, Hong Kong.,The University of Hong Kong Shenzhen Institute of Research and Innovation, Shenzhen, China
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39
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Kumirov VK, Dykstra EM, Hall BM, Anderson WJ, Szyszka TN, Cordes MHJ. Multistep mutational transformation of a protein fold through structural intermediates. Protein Sci 2018; 27:1767-1779. [PMID: 30051937 DOI: 10.1002/pro.3488] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Revised: 07/24/2018] [Accepted: 07/25/2018] [Indexed: 12/24/2022]
Abstract
New protein folds may evolve from existing folds through metamorphic evolution involving a dramatic switch in structure. To mimic pathways by which amino acid sequence changes could induce a change in fold, we designed two folded hybrids of Xfaso 1 and Pfl 6, a pair of homologous Cro protein sequences with ~40% identity but different folds (all-α vs. α + β, respectively). Each hybrid, XPH1 or XPH2, is 85% identical in sequence to its parent, Xfaso 1 or Pfl 6, respectively; 55% identical to its noncognate parent; and ~70% identical to the other hybrid. XPH1 and XPH2 also feature a designed hybrid chameleon sequence corresponding to the C-terminal region, which switched from α-helical to β-sheet structure during Cro evolution. We report solution nuclear magnetic resonance (NMR) structures of XPH1 and XPH2 at 0.3 Å and 0.5 Å backbone root mean square deviation (RMSD), respectively. XPH1 retains a global fold generally similar to Xfaso 1, and XPH2 retains a fold similar to Pfl 6, as measured by TM-align scores (~0.7), DALI Z-scores (7-9), and backbone RMSD (2-3 Å RMSD for the most ordered regions). However, these scores also indicate significant deviations in structure. Most notably, XPH1 and XPH2 have different, and intermediate, secondary structure content relative to Xfaso 1 and Pfl 6. The multistep progression in sequence, from Xfaso 1 to XPH1 to XPH2 to Pfl 6, thus involves both abrupt and gradual changes in folding pattern. The plasticity of some protein folds may allow for "polymetamorphic" evolution through intermediate structures.
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Affiliation(s)
- Vlad K Kumirov
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona, 85721-0088
| | - Emily M Dykstra
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona, 85721-0088
| | - Branwen M Hall
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona, 85721-0088
| | - William J Anderson
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona, 85721-0088
| | - Taylor N Szyszka
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona, 85721-0088
| | - Matthew H J Cordes
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona, 85721-0088
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40
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Dingfelder F, Benke S, Nettels D, Schuler B. Mapping an Equilibrium Folding Intermediate of the Cytolytic Pore Toxin ClyA with Single-Molecule FRET. J Phys Chem B 2018; 122:11251-11261. [PMID: 30156409 DOI: 10.1021/acs.jpcb.8b07026] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The 303-residue cytolytic toxin ClyA forms a stable α-helical monomer. In the presence of detergents or membranes, however, the protein makes a large conformational transition to the protomer state, which is competent for assembly into a dodecameric cytolytic pore. In this study, we map the structure of the ClyA monomer during denaturant-induced unfolding with single-molecule Förster resonance energy transfer (FRET) spectroscopy. To this end, we probe intramolecular distances of six different segments of ClyA by placing donor and acceptor fluorophores at corresponding positions along the chain. We identify an intermediate state that contains the folded core consisting of three of the α-helices that make up the helical bundle present in the structure of both the monomer and the protomer, but with the C- and N-terminal helices unfolded, in accord with the secondary structure content estimated from circular dichroism (CD) spectroscopy. The existence of this intermediate is likely to be a consequence of the structural bistability underlying the biological function of ClyA: The terminal helices are part of the largest rearrangements during protomer formation, and the local differences in stability we detect may prime the protein for the required conformational transition.
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Affiliation(s)
- Fabian Dingfelder
- Department of Biochemistry , University of Zurich , Winterthurerstrasse 190 , 8057 Zurich , Switzerland
| | - Stephan Benke
- Department of Biochemistry , University of Zurich , Winterthurerstrasse 190 , 8057 Zurich , Switzerland
| | - Daniel Nettels
- Department of Biochemistry , University of Zurich , Winterthurerstrasse 190 , 8057 Zurich , Switzerland
| | - Benjamin Schuler
- Department of Biochemistry , University of Zurich , Winterthurerstrasse 190 , 8057 Zurich , Switzerland.,Department of Physics , University of Zurich , Winterthurerstrasse 190 , 8057 Zurich , Switzerland
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Ribeiro S, Ebbinghaus S, Marcos JC. Protein folding and quinary interactions: creating cellular organisation through functional disorder. FEBS Lett 2018; 592:3040-3053. [DOI: 10.1002/1873-3468.13211] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 07/16/2018] [Accepted: 07/29/2018] [Indexed: 01/18/2023]
Affiliation(s)
- Sara Ribeiro
- Centre of Chemistry University of Minho Braga Portugal
| | - Simon Ebbinghaus
- Institute of Physical and Theoretical Chemistry Technical University Braunschweig Germany
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Abstract
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Since
the proposal of Anfinsen’s thermodynamic hypothesis
in 1963, our understanding of protein folding and dynamics has gained
significant appreciation of its nuance and complexity. Intrinsically
disordered proteins, chameleonic sequences, morpheeins, and metamorphic
proteins have broadened the protein folding paradigm. Here, we discuss
noncanonical protein folding patterns, with an emphasis on metamorphic
proteins, and we review known metamorphic proteins that occur naturally
and that have been engineered in the laboratory. Finally, we discuss
research areas surrounding metamorphic proteins that are primed for
future exploration, including evolution, drug discovery, and the quest
for previously unrecognized metamorphs. As we enter an age where we
are capable of complex bioinformatic searches and de novo protein design, we are primed to search for previously unrecognized
metamorphic proteins and to design our own metamorphs to act as targeted,
switchable drugs; biosensors; and more.
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Affiliation(s)
- Acacia F. Dishman
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
| | - Brian F. Volkman
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, United States
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Abstract
It is commonly thought that each globular protein has a single 3D structure, or fold, that fosters its function. In contrast, recent studies have identified several fold-switching proteins whose secondary structures can be remodeled in response to cellular stimuli. Although thought to be rare, we found 96 literature-validated fold-switching proteins by exhaustively searching the database of protein structures [Protein Data Bank (PDB)]. Characterizing these proteins led us to hypothesize that their abundance may be underrepresented in the PDB. Thus, we developed a computational method that identifies fold-switching proteins and used it to estimate that 0.5–4% of PDB proteins switch folds. These results suggest that proteins switch folds with significant frequency, which has implications for cell biology, genomics, and human health. A central tenet of biology is that globular proteins have a unique 3D structure under physiological conditions. Recent work has challenged this notion by demonstrating that some proteins switch folds, a process that involves remodeling of secondary structure in response to a few mutations (evolved fold switchers) or cellular stimuli (extant fold switchers). To date, extant fold switchers have been viewed as rare byproducts of evolution, but their frequency has been neither quantified nor estimated. By systematically and exhaustively searching the Protein Data Bank (PDB), we found ∼100 extant fold-switching proteins. Furthermore, we gathered multiple lines of evidence suggesting that these proteins are widespread in nature. Based on these lines of evidence, we hypothesized that the frequency of extant fold-switching proteins may be underrepresented by the structures in the PDB. Thus, we sought to identify other putative extant fold switchers with only one solved conformation. To do this, we identified two characteristic features of our ∼100 extant fold-switching proteins, incorrect secondary structure predictions and likely independent folding cooperativity, and searched the PDB for other proteins with similar features. Reassuringly, this method identified dozens of other proteins in the literature with indication of a structural change but only one solved conformation in the PDB. Thus, we used it to estimate that 0.5–4% of PDB proteins switch folds. These results demonstrate that extant fold-switching proteins are likely more common than the PDB reflects, which has implications for cell biology, genomics, and human health.
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Zamora-Carreras H, Maestro B, Strandberg E, Ulrich AS, Sanz JM, Jiménez MÁ. Roles of Amphipathicity and Hydrophobicity in the Micelle-Driven Structural Switch of a 14-mer Peptide Core from a Choline-Binding Repeat. Chemistry 2018; 24:5825-5839. [PMID: 29369425 DOI: 10.1002/chem.201704802] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Indexed: 01/16/2023]
Abstract
Choline-binding repeats (CBRs) are ubiquitous sequences with a β-hairpin core that are found in the surface proteins of several microorganisms such as S. pneumoniae (pneumococcus). Previous studies on a 14-mer CBR sequence derived from the pneumoccal LytA autolysin (LytA239-252 peptide) have demonstrated a switch behaviour for this peptide, so that it acquires a stable, native-like β-hairpin conformation in aqueous solution but is reversibly transformed into an amphipathic α-helix in the presence of detergent micelles. With the aim of understanding the factors responsible for this unusual β-hairpin to α-helix transition, and to specifically assess the role of peptide hydrophobicity and helical amphipathicity in the process, we designed a series of LytA239-252 variants affecting these two parameters and studied their interaction with dodecylphosphocholine (DPC) micelles by solution NMR, circular dichroism and fluorescence spectroscopies. Our results indicate that stabilising cross-strand interactions become essential for β-hairpin stability in the absence of optimal turn sequences. Moreover, both amphipathicity and hydrophobicity display comparable importance for helix stabilisation of CBR-derived peptides in micelles, indicating that these sequences represent a novel class of micelle/membrane-interacting peptides.
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Affiliation(s)
- Héctor Zamora-Carreras
- Instituto de Química Física Rocasolano (IQFR), Consejo Superior de Investigaciones Científicas (CSIC), Serrano 119, 28006, Madrid, Spain
| | - Beatriz Maestro
- Instituto de Biología MolecularyCelular, Universidad Miguel Hernández, Elche, 03202, Alicante, Spain
| | - Erik Strandberg
- Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology (KIT), P.O. Box 3640, 76021, Karlsruhe, Germany
| | - Anne S Ulrich
- Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology (KIT), P.O. Box 3640, 76021, Karlsruhe, Germany.,Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131, Karlsruhe, Germany
| | - Jesús M Sanz
- Instituto de Biología MolecularyCelular, Universidad Miguel Hernández, Elche, 03202, Alicante, Spain.,Biological Research Centre (CIB), Consejo Superior de Investigaciones Científicas (CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - M Ángeles Jiménez
- Instituto de Química Física Rocasolano (IQFR), Consejo Superior de Investigaciones Científicas (CSIC), Serrano 119, 28006, Madrid, Spain
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Amyloid growth and membrane damage: Current themes and emerging perspectives from theory and experiments on Aβ and hIAPP. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1625-1638. [PMID: 29501606 DOI: 10.1016/j.bbamem.2018.02.022] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 02/21/2018] [Accepted: 02/21/2018] [Indexed: 12/15/2022]
Abstract
Alzheimer's Disease (AD) and Type 2 diabetes mellitus (T2DM) are two incurable diseases both hallmarked by an abnormal deposition of the amyloidogenic peptides Aβ and Islet Amyloid Polypeptide (IAPP) in affected tissues. Epidemiological data demonstrate that patients suffering from diabetes are at high risk of developing AD, thus making the search for factors common to the two pathologies of special interest for the design of new therapies. Accumulating evidence suggests that the toxic properties of both Aβ or IAPP are ascribable to their ability to damage the cell membrane. However, the molecular details describing Aβ or IAPP interaction with membranes are poorly understood. This review focuses on biophysical and in silico studies addressing these topics. Effects of calcium, cholesterol and membrane lipid composition in driving aberrant Aβ or IAPP interaction with the membrane will be specifically considered. The cross correlation of all these factors appears to be a key issue not only to shed light in the countless and often controversial reports relative to this area but also to gain valuable insights into the central events leading to membrane damage caused by amyloidogenic peptides. This article is part of a Special Issue entitled: Protein Aggregation and Misfolding at the Cell Membrane Interface edited by Ayyalusamy Ramamoorthy.
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