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Sutinen A, Nguyen GTT, Raasakka A, Muruganandam G, Loris R, Ylikallio E, Tyynismaa H, Bartesaghi L, Ruskamo S, Kursula P. Structural insights into Charcot-Marie-Tooth disease-linked mutations in human GDAP1. FEBS Open Bio 2022; 12:1306-1324. [PMID: 35509130 PMCID: PMC9249340 DOI: 10.1002/2211-5463.13422] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/25/2022] [Accepted: 05/03/2022] [Indexed: 11/11/2022] Open
Abstract
Charcot-Marie-Tooth disease (CMT) is the most common inherited peripheral polyneuropathy in humans, and its different subtypes are linked to mutations in dozens of different genes. Mutations in ganglioside-induced differentiation-associated protein 1 (GDAP1) cause two types of CMT, demyelinating CMT4A and axonal CMT2K. The GDAP1-linked CMT genotypes are mainly missense point mutations. Despite clinical profiling and in vivo studies on the mutations, the etiology of GDAP1-linked CMT is poorly understood. Here, we describe the biochemical and structural properties of the Finnish founding CMT2K mutation H123R as well as CMT2K-linked R120W, both of which are autosomal dominant mutations. The disease variant proteins retain close to normal structure and solution behaviour, but both present a significant decrease in thermal stability. Using GDAP1 variant crystal structures, we identify a side chain interaction network between helices ⍺3, ⍺6, and ⍺7, which is affected by CMT mutations, as well as a hinge in the long helix ⍺6, which is linked to structural flexibility. Structural analysis of GDAP1 indicates that CMT may arise from disruption of specific intra- and intermolecular interaction networks, leading to alterations in GDAP1 structure and stability, and eventually, insufficient motor and sensory neuron function.
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Affiliation(s)
- Aleksi Sutinen
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Finland
| | - Giang Thi Tuyet Nguyen
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Finland
| | - Arne Raasakka
- Department of Biomedicine, University of Bergen, Norway
| | - Gopinath Muruganandam
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium.,Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Belgium
| | - Remy Loris
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium.,Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Belgium
| | - Emil Ylikallio
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Finland.,Clinical Neurosciences, Helsinki University Hospital, Neurology, Finland
| | - Henna Tyynismaa
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Finland
| | | | - Salla Ruskamo
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Finland
| | - Petri Kursula
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Finland.,Department of Biomedicine, University of Bergen, Norway
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Meskers SCJ. Circular Polarization of Luminescence as a Tool To Study Molecular Dynamical Processes. CHEMPHOTOCHEM 2021. [DOI: 10.1002/cptc.202100154] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Stefan C. J. Meskers
- Molecular Materials and Nanosystems and Institute for Complex Molecular Systems Eindhoven University of Technology P.O. box 513 (STW 4.37) NL 5600 MB Eindhoven Netherlands
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3
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The role of circular dichroism spectroscopy in the era of integrative structural biology. Curr Opin Struct Biol 2019; 58:191-196. [DOI: 10.1016/j.sbi.2019.04.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 03/28/2019] [Accepted: 04/01/2019] [Indexed: 12/25/2022]
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4
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Hallin EI, Eriksen MS, Baryshnikov S, Nikolaienko O, Grødem S, Hosokawa T, Hayashi Y, Bramham CR, Kursula P. Structure of monomeric full-length ARC sheds light on molecular flexibility, protein interactions, and functional modalities. J Neurochem 2018; 147:323-343. [DOI: 10.1111/jnc.14556] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 06/29/2018] [Accepted: 07/12/2018] [Indexed: 12/18/2022]
Affiliation(s)
- Erik I. Hallin
- Department of Biomedicine; University of Bergen; Bergen Norway
| | - Maria S. Eriksen
- Department of Biomedicine; University of Bergen; Bergen Norway
- K.G. Jebsen Centre for Neuropsychiatric Disorders; University of Bergen; Bergen Norway
| | - Sergei Baryshnikov
- Department of Biomedicine; University of Bergen; Bergen Norway
- K.G. Jebsen Centre for Neuropsychiatric Disorders; University of Bergen; Bergen Norway
| | - Oleksii Nikolaienko
- Department of Biomedicine; University of Bergen; Bergen Norway
- K.G. Jebsen Centre for Neuropsychiatric Disorders; University of Bergen; Bergen Norway
| | - Sverre Grødem
- Department of Biomedicine; University of Bergen; Bergen Norway
- K.G. Jebsen Centre for Neuropsychiatric Disorders; University of Bergen; Bergen Norway
| | - Tomohisa Hosokawa
- Department of Pharmacology; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - Yasunori Hayashi
- Department of Pharmacology; Kyoto University Graduate School of Medicine; Kyoto Japan
| | - Clive R. Bramham
- Department of Biomedicine; University of Bergen; Bergen Norway
- K.G. Jebsen Centre for Neuropsychiatric Disorders; University of Bergen; Bergen Norway
| | - Petri Kursula
- Department of Biomedicine; University of Bergen; Bergen Norway
- Faculty of Biochemistry and Molecular Medicine; University of Oulu; Oulu Finland
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Harnessing the Combined Power of SAXS and NMR. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1105:171-180. [DOI: 10.1007/978-981-13-2200-6_11] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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6
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Heller GT, Aprile FA, Vendruscolo M. Methods of probing the interactions between small molecules and disordered proteins. Cell Mol Life Sci 2017; 74:3225-3243. [PMID: 28631009 PMCID: PMC5533867 DOI: 10.1007/s00018-017-2563-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 06/01/2017] [Indexed: 12/15/2022]
Abstract
It is generally recognized that a large fraction of the human proteome is made up of proteins that remain disordered in their native states. Despite the fact that such proteins play key biological roles and are involved in many major human diseases, they still represent challenging targets for drug discovery. A major bottleneck for the identification of compounds capable of interacting with these proteins and modulating their disease-promoting behaviour is the development of effective techniques to probe such interactions. The difficulties in carrying out binding measurements have resulted in a poor understanding of the mechanisms underlying these interactions. In order to facilitate further methodological advances, here we review the most commonly used techniques to probe three types of interactions involving small molecules: (1) those that disrupt functional interactions between disordered proteins; (2) those that inhibit the aberrant aggregation of disordered proteins, and (3) those that lead to binding disordered proteins in their monomeric states. In discussing these techniques, we also point out directions for future developments.
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Affiliation(s)
- Gabriella T Heller
- Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
| | - Francesco A Aprile
- Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, UK
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7
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Kumagai PS, Araujo APU, Lopes JLS. Going deep into protein secondary structure with synchrotron radiation circular dichroism spectroscopy. Biophys Rev 2017; 9:517-527. [PMID: 28825203 DOI: 10.1007/s12551-017-0314-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 08/03/2017] [Indexed: 10/25/2022] Open
Abstract
Circular dichroism (CD) spectroscopy is a fast, powerful, well-established, and widely used analytical technique in the biophysical and structural biology community to study protein secondary structure and to track changes in protein conformation in different environments. The use of the intense light of a synchrotron beam as the light source for collecting CD measurements has emerged as an enhanced method, known as synchrotron radiation circular dichroism (SRCD) spectroscopy, that has several advantages over the conventional CD method, including a significant spectral range extension for data collection, deeper access to the lower limit (cut-off) of conventional CD spectroscopy, an improved signal-to-noise ratio to increase accuracy in the measurements, and the possibility to collect measurements in highly absorbing solutions. In this review, we discuss different applications of the SRCD technique by researchers from Latin America. In this context, we specifically look at the use of this method for examining the secondary structure and conformational behavior of proteins belonging to the four main classes of the hierarchical protein domain classification CATH (Class, Architecture, Topology, Homology) database, focusing on the advantages and improvements associated with SRCD spectroscopy in terms of characterizing proteins composed of different structural elements.
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Affiliation(s)
- Patricia S Kumagai
- Instituto de Física de São Carlos, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Ana P U Araujo
- Instituto de Física de São Carlos, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Jose L S Lopes
- Departamento Física Aplicada, Instituto de Física,, Universidade de São Paulo, Rua do Matão 1371, Cidade Universitária, São Paulo, SP, 05508-090, Brazil.
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8
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Probing the Molecular Mechanism of Human Soluble Guanylate Cyclase Activation by NO in vitro and in vivo. Sci Rep 2017; 7:43112. [PMID: 28230071 PMCID: PMC5322342 DOI: 10.1038/srep43112] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 01/19/2017] [Indexed: 11/12/2022] Open
Abstract
Soluble guanylate cyclase (sGC) is a heme-containing metalloprotein in NO-sGC-cGMP signaling. NO binds to the heme of sGC to catalyze the synthesis of the second messenger cGMP, which plays a critical role in several physiological processes. However, the molecular mechanism for sGC to mediate the NO signaling remains unclear. Here fluorophore FlAsH-EDT2 and fluorescent proteins were employed to study the NO-induced sGC activation. FlAsH-EDT2 labeling study revealed that NO binding to the H-NOX domain of sGC increased the distance between H-NOX and PAS domain and the separation between H-NOX and coiled-coil domain. The heme pocket conformation changed from “closed” to “open” upon NO binding. In addition, the NO-induced conformational change of sGC was firstly investigated in vivo through fluorescence lifetime imaging microscopy. The results both in vitro and in vivo indicated the conformational change of the catalytic domain of sGC from “open” to “closed” upon NO binding. NO binding to the heme of H-NOX domain caused breaking of Fe-N coordination bond, initiated the domain moving and conformational change, induced the allosteric effect of sGC to trigger the NO-signaling from H-NOX via PAS & coiled-coil to the catalytic domain, and ultimately stimulates the cyclase activity of sGC.
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9
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Zhou M, Li Q, Wang R. Current Experimental Methods for Characterizing Protein-Protein Interactions. ChemMedChem 2016; 11:738-56. [PMID: 26864455 PMCID: PMC7162211 DOI: 10.1002/cmdc.201500495] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 01/08/2016] [Indexed: 12/14/2022]
Abstract
Protein molecules often interact with other partner protein molecules in order to execute their vital functions in living organisms. Characterization of protein-protein interactions thus plays a central role in understanding the molecular mechanism of relevant protein molecules, elucidating the cellular processes and pathways relevant to health or disease for drug discovery, and charting large-scale interaction networks in systems biology research. A whole spectrum of methods, based on biophysical, biochemical, or genetic principles, have been developed to detect the time, space, and functional relevance of protein-protein interactions at various degrees of affinity and specificity. This article presents an overview of these experimental methods, outlining the principles, strengths and limitations, and recent developments of each type of method.
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Affiliation(s)
- Mi Zhou
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China
| | - Qing Li
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China
| | - Renxiao Wang
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China.
- State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Avenida Wai Long, Macau, 999078, People's Republic of China.
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10
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Zhou M, Li Q, Wang R. Current Experimental Methods for Characterizing Protein-Protein Interactions. ChemMedChem 2016. [PMID: 26864455 DOI: 10.1002/cmdc.201500495.] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Protein molecules often interact with other partner protein molecules in order to execute their vital functions in living organisms. Characterization of protein-protein interactions thus plays a central role in understanding the molecular mechanism of relevant protein molecules, elucidating the cellular processes and pathways relevant to health or disease for drug discovery, and charting large-scale interaction networks in systems biology research. A whole spectrum of methods, based on biophysical, biochemical, or genetic principles, have been developed to detect the time, space, and functional relevance of protein-protein interactions at various degrees of affinity and specificity. This article presents an overview of these experimental methods, outlining the principles, strengths and limitations, and recent developments of each type of method.
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Affiliation(s)
- Mi Zhou
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China
| | - Qing Li
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China
| | - Renxiao Wang
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China. .,State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Avenida Wai Long, Macau, 999078, People's Republic of China.
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11
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Uporov IV, Forlemu NY, Nori R, Aleksandrov T, Sango BA, Mbote YEB, Pothuganti S, Thomasson KA. Introducing DInaMo: A Package for Calculating Protein Circular Dichroism Using Classical Electromagnetic Theory. Int J Mol Sci 2015; 16:21237-76. [PMID: 26370961 PMCID: PMC4613251 DOI: 10.3390/ijms160921237] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Revised: 06/09/2015] [Accepted: 06/30/2015] [Indexed: 01/23/2023] Open
Abstract
The dipole interaction model is a classical electromagnetic theory for calculating circular dichroism (CD) resulting from the π-π* transitions of amides. The theoretical model, pioneered by J. Applequist, is assembled into a package, DInaMo, written in Fortran allowing for treatment of proteins. DInaMo reads Protein Data Bank formatted files of structures generated by molecular mechanics or reconstructed secondary structures. Crystal structures cannot be used directly with DInaMo; they either need to be rebuilt with idealized bond angles and lengths, or they need to be energy minimized to adjust bond lengths and bond angles because it is common for crystal structure geometries to have slightly short bond lengths, and DInaMo is sensitive to this. DInaMo reduces all the amide chromophores to points with anisotropic polarizability and all nonchromophoric aliphatic atoms including hydrogens to points with isotropic polarizability; all other atoms are ignored. By determining the interactions among the chromophoric and nonchromophoric parts of the molecule using empirically derived polarizabilities, the rotational and dipole strengths are determined leading to the calculation of CD. Furthermore, ignoring hydrogens bound to methyl groups is initially explored and proves to be a good approximation. Theoretical calculations on 24 proteins agree with experiment showing bands with similar morphology and maxima.
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Affiliation(s)
- Igor V Uporov
- Chemistry Department, University of North Dakota, 151 Cornell St. Stop 9024, Grand Forks, ND 58202, USA.
- Faculty of Chemistry, M. V. Lomonosov Moscow State University, GSP-1, 1-3 Leninskiye Gory, 119991 Moscow, Russia.
| | - Neville Y Forlemu
- Chemistry Department, University of North Dakota, 151 Cornell St. Stop 9024, Grand Forks, ND 58202, USA.
- Georgia Gwinnett College, 1000 University Center Lane, Lawrenceville, GA 30043, USA.
| | - Rahul Nori
- Chemistry Department, University of North Dakota, 151 Cornell St. Stop 9024, Grand Forks, ND 58202, USA.
| | - Tsvetan Aleksandrov
- Chemistry Department, University of North Dakota, 151 Cornell St. Stop 9024, Grand Forks, ND 58202, USA.
| | - Boris A Sango
- Chemistry Department, University of North Dakota, 151 Cornell St. Stop 9024, Grand Forks, ND 58202, USA.
| | - Yvonne E Bongfen Mbote
- Chemistry Department, University of North Dakota, 151 Cornell St. Stop 9024, Grand Forks, ND 58202, USA.
- James E. Hurley College of Science & Mathematics, Oklahoma Baptist University, OBU Box 61772, 500 W. University, Shawnee, OK 74804, USA.
| | - Sandeep Pothuganti
- Chemistry Department, University of North Dakota, 151 Cornell St. Stop 9024, Grand Forks, ND 58202, USA.
| | - Kathryn A Thomasson
- Chemistry Department, University of North Dakota, 151 Cornell St. Stop 9024, Grand Forks, ND 58202, USA.
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Overestimated accuracy of circular dichroism in determining protein secondary structure. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2013; 42:455-61. [PMID: 23467783 DOI: 10.1007/s00249-013-0896-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Revised: 01/22/2013] [Accepted: 02/19/2013] [Indexed: 10/27/2022]
Abstract
Circular dichroism (CD) is a spectroscopic technique widely used for estimating protein secondary structures in aqueous solution, but its accuracy has been doubted in recent work. In the present paper, the contents of nine globular proteins with known secondary structures were determined by CD spectroscopy and Fourier transform infrared spectroscopy (FTIR) in aqueous solution. A large deviation was found between the CD spectra and X-ray data, even when the experimental conditions were optimized. The content determined by FTIR was in good agreement with the X-ray crystallography data. Therefore, CD spectra are not recommended for directly calculating the content of a protein's secondary structure.
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Réfrégiers M, Wien F, Ta HP, Premvardhan L, Bac S, Jamme F, Rouam V, Lagarde B, Polack F, Giorgetta JL, Ricaud JP, Bordessoule M, Giuliani A. DISCO synchrotron-radiation circular-dichroism endstation at SOLEIL. JOURNAL OF SYNCHROTRON RADIATION 2012; 19:831-835. [PMID: 22898965 DOI: 10.1107/s0909049512030002] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 07/01/2012] [Indexed: 06/01/2023]
Abstract
The new synchrotron-radiation circular-dichroism (SRCD) endstation on the UV-visible synchrotron beamline DISCO has been commissioned at the SOLEIL synchrotron. The design has been focused on preservation of a high degree of linear polarization at high flux and moderate resolving power covering the vacuum ultraviolet to visible spectral range (125-600 nm). The beam dimensions have been set to 4 mm × 4 mm at 1 nm bandwidth for lower sample degradation. The nitrogen-purged sample chamber fits three types of sample holders accommodating conventional round cell mounting, automated rotation of the samples, as well as a microfluidic set-up. Automated temperature-controlled data collection on microvolumes is now available to the biology and chemistry communities. Macromolecules including membrane proteins, soluble proteins, bio-nanotubes, sugars, DNA and RNAs are now routinely investigated.
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Flayhan A, Wien F, Paternostre M, Boulanger P, Breyton C. New insights into pb5, the receptor binding protein of bacteriophage T5, and its interaction with its Escherichia coli receptor FhuA. Biochimie 2012; 94:1982-9. [PMID: 22659573 DOI: 10.1016/j.biochi.2012.05.021] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 05/22/2012] [Indexed: 01/13/2023]
Abstract
The majority of bacterial viruses are bacteriophages bearing a tail that serves to recognise the bacterial surface and deliver the genome into the host cell. Infection is initiated by the irreversible interaction between the viral receptor binding protein (RBP) and a receptor at the surface of the bacterium. This interaction results ultimately in the phage DNA release in the host cytoplasm. Phage T5 infects Escherichia coli after binding of its RBP pb5 to the outer membrane ferrichrome transporter FhuA. Here, we have studied the complex formed by pb5 and FhuA by a variety of biophysical and biochemical techniques. We show that unlike RBPs of known structures, pb5 probably folds as a unique domain fulfilling both functions of binding to the host receptor and interaction with the rest of the phage. Pb5 likely binds to the domain occluding the β-barrel of FhuA as well as to external loops of the barrel. Furthermore, upon binding to FhuA, pb5 undergoes conformational changes, at the secondary and tertiary structure level that would be the key to the transmission of the signal through the tail to the capsid, triggering DNA release. This is the first structural information regarding the binding of a RBP to a proteic receptor.
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Affiliation(s)
- Ali Flayhan
- CEA, Institut de Biologie Structurale Jean-Pierre Ebel, Grenoble, France
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15
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Synchrotron radiation circular dichroism (SRCD) spectroscopy: an enhanced method for examining protein conformations and protein interactions. Biochem Soc Trans 2010; 38:861-73. [PMID: 20658968 DOI: 10.1042/bst0380861] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
CD (circular dichroism) spectroscopy is a well-established technique in structural biology. SRCD (synchrotron radiation circular dichroism) spectroscopy extends the utility and applications of conventional CD spectroscopy (using laboratory-based instruments) because the high flux of a synchrotron enables collection of data at lower wavelengths (resulting in higher information content), detection of spectra with higher signal-to-noise levels and measurements in the presence of absorbing components (buffers, salts, lipids and detergents). SRCD spectroscopy can provide important static and dynamic structural information on proteins in solution, including secondary structures of intact proteins and their domains, protein stability, the differences between wild-type and mutant proteins, the identification of natively disordered regions in proteins, and the dynamic processes of protein folding and membrane insertion and the kinetics of enzyme reactions. It has also been used to effectively study protein interactions, including protein-protein complex formation involving either induced-fit or rigid-body mechanisms, and protein-lipid complexes. A new web-based bioinformatics resource, the Protein Circular Dichroism Data Bank (PCDDB), has been created which enables archiving, access and analyses of CD and SRCD spectra and supporting metadata, now making this information publicly available. To summarize, the developing method of SRCD spectroscopy has the potential for playing an important role in new types of studies of protein conformations and their complexes.
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Abstract
Circular dichroism (CD) spectroscopy is a well-established technique for the study of proteins. Synchrotron radiation circular dichroism (SRCD) spectroscopy extends the utility of conventional CD spectroscopy (i.e. using laboratory-based instruments) because the high light flux from a synchrotron enables collection of data to lower wavelengths, detection of spectra with higher signal-to-noise levels and measurements in the presence of strongly absorbing non-chiral components such as salts, buffers, lipids and detergents. This review describes developments in instrumentation, methodologies and bioinformatics that have enabled new applications of the SRCD technique for the study of proteins. It includes examples of the use of SRCD spectroscopy for providing static and dynamic structural information on molecules, including determinations of secondary structures of intact proteins and domains, assessment of protein stability, detection of conformational changes associated with ligand and drug binding, monitoring of environmental effects, examination of the processes of protein folding and membrane insertion, comparisons of mutant and modified proteins, identification of intermolecular interactions and complex formation, determination of the dispositions of proteins in membranes, identification of natively disordered proteins and their binding partners and examination of the carbohydrate components of glycoproteins. It also discusses how SRCD can be used in conjunction with macromolecular crystallography and other biophysical techniques to provide a more complete picture of protein structures and functions, including how proteins interact with other macromolecules and ligands. This review also includes a discussion of potential new applications in structural and functional genomics using SRCD spectroscopy and future instrumentation and bioinformatics developments that will enable such studies. Finally, the appendix describes a number of computational/bioinformatics resources for secondary structure analyses that take advantage of the improved data quality available from SRCD. In summary, this review discusses how SRCD can be used for a wide range of structural and functional studies of proteins.
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United we stand: combining structural methods. Curr Opin Struct Biol 2008; 18:617-22. [DOI: 10.1016/j.sbi.2008.07.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Accepted: 07/29/2008] [Indexed: 01/20/2023]
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18
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Miles AJ, Drechsler A, Kristan K, Anderluh G, Norton RS, Wallace BA, Separovic F. The effects of lipids on the structure of the eukaryotic cytolysin equinatoxin II: a synchrotron radiation circular dichroism spectroscopic study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1778:2091-6. [PMID: 18440301 DOI: 10.1016/j.bbamem.2008.04.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2008] [Revised: 03/27/2008] [Accepted: 04/01/2008] [Indexed: 11/28/2022]
Abstract
Synchrotron radiation circular dichroism (SRCD) spectroscopy studies of the eukaryotic pore-forming protein equinatoxin II (EqtII) were carried out in solution and in the presence of micelles or small unilamellar vesicles (SUV) of different lipid composition. The SRCD structural data was correlated with calcein leakage from SUV and with partitioning of EqtII to liposomes, and micelles, according to haemolysis assays. The structure of EqtII in water and dodecylphosphocholine micelles as determined by SRCD was similar to the values calculated from crystal and solution structures of the protein, and no changes were observed with the addition of sphingomyelin (SM). SM is required to trigger pore formation in biological and model membranes, but our results suggest that SM alone is not sufficient to trigger dissociation of the N-terminal helix and further structural rearrangements required to produce a pore. Significant changes in conformation of EqtII were detected with unsaturated phospholipid (DOPC) vesicles when SM was added, but not with saturated phospholipids (DMPC), which suggests that not only is membrane curvature important, but also the fluidity of the bilayer. The SRCD data indicated that the EqtII structure in the presence of DOPC:SM SUV represents the 'bound' state and the 'free' state is represented by spectra for DOPC or DOPC:Chol vesicles, which correlates with the high lytic activity for SUV of DOPC:SM. The SRCD results provide insight into the lipid requirements for structural rearrangements associated with EqtII toxicity and lysis.
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Affiliation(s)
- Andrew J Miles
- Department of Crystallography, Birkbeck College, University of London, London WC1E 7HX, UK
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Cowieson NP, King G, Cookson D, Ross I, Huber T, Hume DA, Kobe B, Martin JL. Cortactin adopts a globular conformation and bundles actin into sheets. J Biol Chem 2008; 283:16187-93. [PMID: 18375393 DOI: 10.1074/jbc.m708917200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cortactin is a filamentous actin-binding protein that plays a pivotal role in translating environmental signals into coordinated rearrangement of the cytoskeleton. The dynamic reorganization of actin in the cytoskeleton drives processes including changes in cell morphology, cell migration, and phagocytosis. In general, structural proteins of the cytoskeleton bind in the N-terminal region of cortactin and regulatory proteins in the C-terminal region. Previous structural studies have reported an extended conformation for cortactin. It is therefore unclear how cortactin facilitates cross-talk between structural proteins and their regulators. In the study presented here, circular dichroism, chemical cross-linking, and small angle x-ray scattering are used to demonstrate that cortactin adopts a globular conformation, thereby bringing distant parts of the molecule into close proximity. In addition, the actin bundling activity of cortactin is characterized, showing that fully polymerized actin filaments are bundled into sheet-like structures. We present a low resolution structure that suggests how the various domains of cortactin interact to coordinate its array of binding partners at sites of actin branching.
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Affiliation(s)
- Nathan P Cowieson
- Institute for Molecular Bioscience and Australian Research Council (ARC) Special Research Centre for Functional and Applied Genomics, University of Queensland, Brisbane QLD 4072 Australia
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