1
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Hildebrandt P. Vibrational Spectroscopy of Phytochromes. Biomolecules 2023; 13:1007. [PMID: 37371587 DOI: 10.3390/biom13061007] [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: 05/31/2023] [Revised: 06/12/2023] [Accepted: 06/14/2023] [Indexed: 06/29/2023] Open
Abstract
Phytochromes are biological photoswitches that translate light into physiological functions. Spectroscopic techniques are essential tools for molecular research into these photoreceptors. This review is directed at summarizing how resonance Raman and IR spectroscopy contributed to an understanding of the structure, dynamics, and reaction mechanism of phytochromes, outlining the substantial experimental and theoretical challenges and describing the strategies to master them. It is shown that the potential of the various vibrational spectroscopic techniques can be most efficiently exploited using integral approaches via a combination of theoretical methods as well as other experimental techniques.
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Affiliation(s)
- Peter Hildebrandt
- Institut für Chemie, Technische Universität Berlin, Sekr. PC 14, Straße des 17. Juni 135, D-10623 Berlin, Germany
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2
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Ultrafast proton-coupled isomerization in the phototransformation of phytochrome. Nat Chem 2022; 14:823-830. [PMID: 35577919 PMCID: PMC9252900 DOI: 10.1038/s41557-022-00944-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 04/01/2022] [Indexed: 11/08/2022]
Abstract
The biological function of phytochromes is triggered by an ultrafast photoisomerization of the tetrapyrrole chromophore biliverdin between two rings denoted C and D. The mechanism by which this process induces extended structural changes of the protein is unclear. Here we report ultrafast proton-coupled photoisomerization upon excitation of the parent state (Pfr) of bacteriophytochrome Agp2. Transient deprotonation of the chromophore's pyrrole ring D or ring C into a hydrogen-bonded water cluster, revealed by a broad continuum infrared band, is triggered by electronic excitation, coherent oscillations and the sudden electric-field change in the excited state. Subsequently, a dominant fraction of the excited population relaxes back to the Pfr state, while ~35% follows the forward reaction to the photoproduct. A combination of quantum mechanics/molecular mechanics calculations and ultrafast visible and infrared spectroscopies demonstrates how proton-coupled dynamics in the excited state of Pfr leads to a restructured hydrogen-bond environment of early Lumi-F, which is interpreted as a trigger for downstream protein structural changes.
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3
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Rydzewski J, Walczewska-Szewc K, Czach S, Nowak W, Kuczera K. Enhancing the Inhomogeneous Photodynamics of Canonical Bacteriophytochrome. J Phys Chem B 2022; 126:2647-2657. [PMID: 35357137 PMCID: PMC9014414 DOI: 10.1021/acs.jpcb.2c00131] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
The ability of phytochromes
to act as photoswitches in plants and
microorganisms depends on interactions between a bilin-like chromophore
and a host protein. The interconversion occurs between the spectrally
distinct red (Pr) and far-red (Pfr) conformers. This conformational
change is triggered by the photoisomerization of the chromophore D-ring
pyrrole. In this study, as a representative example of a phytochrome-bilin
system, we consider biliverdin IXα (BV) bound to bacteriophytochrome
(BphP) from Deinococcus radiodurans. In the absence
of light, we use an enhanced sampling molecular dynamics (MD) method
to overcome the photoisomerization energy barrier. We find that the
calculated free energy (FE) barriers between essential metastable
states agree with spectroscopic results. We show that the enhanced
dynamics of the BV chromophore in BphP contributes to triggering nanometer-scale
conformational movements that propagate by two experimentally determined
signal transduction pathways. Most importantly, we describe how the
metastable states enable a thermal transition known as the dark reversion
between Pfr and Pr, through a previously unknown intermediate state
of Pfr. We present the heterogeneity of temperature-dependent Pfr
states at the atomistic level. This work paves a way toward understanding
the complete mechanism of the photoisomerization of a bilin-like chromophore
in phytochromes.
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Affiliation(s)
- Jakub Rydzewski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100, Torun, Poland
| | - Katarzyna Walczewska-Szewc
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100, Torun, Poland
| | - Sylwia Czach
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100, Torun, Poland
| | - Wieslaw Nowak
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100, Torun, Poland
| | - Krzysztof Kuczera
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66047, United States.,Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
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4
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Okuda Y, Miyoshi R, Kamo T, Fujisawa T, Nagae T, Mishima M, Eki T, Hirose Y, Unno M. Raman Spectroscopy of an Atypical C15-E,syn Bilin Chromophore in Cyanobacteriochrome RcaE. J Phys Chem B 2022; 126:813-821. [DOI: 10.1021/acs.jpcb.1c09652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yuji Okuda
- Department of Chemistry and Applied Chemistry, Faculty of Science and Engineering, Saga University, Saga 840-8502, Japan
| | - Risako Miyoshi
- Department of Chemistry and Applied Chemistry, Faculty of Science and Engineering, Saga University, Saga 840-8502, Japan
| | - Takanari Kamo
- Department of Applied Chemistry and Life Science, Toyohashi University of Technology, Toyohashi, Aichi 441-8580, Japan
| | - Tomotsumi Fujisawa
- Department of Chemistry and Applied Chemistry, Faculty of Science and Engineering, Saga University, Saga 840-8502, Japan
| | - Takayuki Nagae
- Synchrotron Radiation Research Center, Nagoya University, Chikusa, Nagoya 464-8603, Japan
| | - Masaki Mishima
- Department of Molecular Biophysics, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Toshihiko Eki
- Department of Applied Chemistry and Life Science, Toyohashi University of Technology, Toyohashi, Aichi 441-8580, Japan
| | - Yuu Hirose
- Department of Applied Chemistry and Life Science, Toyohashi University of Technology, Toyohashi, Aichi 441-8580, Japan
| | - Masashi Unno
- Department of Chemistry and Applied Chemistry, Faculty of Science and Engineering, Saga University, Saga 840-8502, Japan
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5
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Jähnigen S, Sebastiani D. Carbon Atoms Speaking Out: How the Geometric Sensitivity of 13C Chemical Shifts Leads to Understanding the Colour Tuning of Phycocyanobilin in Cph1 and AnPixJ. Molecules 2020; 25:E5505. [PMID: 33255423 PMCID: PMC7727823 DOI: 10.3390/molecules25235505] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 11/29/2022] Open
Abstract
We present a combined quantum mechanics/molecular mechanics (QM/MM) molecular dynamics-statistical approach for the interpretation of nuclear magnetic resonance (NMR) chemical shift patterns in phycocyanobilin (PCB). These were originally associated with colour tuning upon photoproduct formation in red/green-absorbing cyanobacteriochrome AnPixJg2 and red/far-red-absorbing phytochrome Cph1Δ2. We pursue an indirect approach without computation of the absorption frequencies since the molecular geometry of cofactor and protein are not accurately known. Instead, we resort to a heuristic determination of the conjugation length in PCB through the experimental NMR chemical shift patterns, supported by quantum chemical calculations. We have found a characteristic correlation pattern of 13C chemical shifts to specific bond orders within the π-conjugated system, which rests on the relative position of carbon atoms with respect to electron-withdrawing groups and the polarisation of covalent bonds. We propose the inversion of this regioselective relationship using multivariate statistics and to apply it to the known experimental NMR chemical shifts in order to predict changes in the bond alternation pattern. Therefrom the extent of electronic conjugation, and eventually the change in absorption frequency, can be derived. In the process, the consultation of explicit mesomeric formulae plays an important role to qualitatively account for possible conjugation scenarios of the chromophore. While we are able to consistently associate the NMR chemical shifts with hypsochromic and bathochromic shifts in the Pg and Pfr, our approach represents an alternative method to increase the explanatory power of NMR spectroscopic data in proteins.
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Affiliation(s)
| | - Daniel Sebastiani
- Institut für Chemie, Naturwissenschaftliche Fakultät II, Martin-Luther-Universität Halle-Wittenberg, von-Danckelmann-Platz 4, 06120 Halle (Saale), Germany;
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6
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Antelo GT, Sánchez-Lamas M, Goldbaum FA, Otero LH, Bonomi HR, Rinaldi J. A Spectroscopy-based Methodology for Rapid Screening and Characterization of Phytochrome Photochemistry in Search of Pfr-favored Variants. Photochem Photobiol 2020; 96:1221-1232. [PMID: 32683707 DOI: 10.1111/php.13313] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 07/11/2020] [Indexed: 11/30/2022]
Abstract
Phytochromes are photosensitive proteins with a covalently bound open-chain chromophore that can switch between two principal states: red light absorbing Pr and far-red light absorbing Pfr. Our group has previously shown that the bacteriophytochrome from Xanthomonas campestris pv. campestris (XccBphP) is a bathy-like phytochrome that uses biliverdin IXα as a co-factor and is involved in bacterial virulence. To date, the XccBphP crystal structure could only be solved in the Pr state, while the structure of its Pfr state remains elusive. The aims of this work were to develop an efficient screening methodology for the rapid characterization and to identify XccBphP variants that favor the Pfr form. The screening approach developed here consists in analyzing the UV-Vis absorption behavior of clarified crude extracts containing recombinant phytochromes. This strategy has allowed us to quickly explore over a hundred XccBphP variants, characterize multiple variants and identify Pfr-favored candidates. The high-quality data obtained enabled not only a qualitative, but also a quantitative characterization of their photochemistry. This method could be easily adapted to other phytochromes or other photoreceptor families.
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Affiliation(s)
| | | | | | - Lisandro Horacio Otero
- Fundación Instituto Leloir, IIBBA-CONICET, Buenos Aires, Argentina.,Plataforma Argentina de Biología Estructural y Metabolómica PLABEM, Buenos Aires, Argentina
| | | | - Jimena Rinaldi
- Fundación Instituto Leloir, IIBBA-CONICET, Buenos Aires, Argentina
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7
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Gourinchas G, Vide U, Winkler A. Influence of the N-terminal segment and the PHY-tongue element on light-regulation in bacteriophytochromes. J Biol Chem 2019; 294:4498-4510. [PMID: 30683693 PMCID: PMC6433076 DOI: 10.1074/jbc.ra118.007260] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 01/22/2019] [Indexed: 11/30/2022] Open
Abstract
Photoreceptors enable the integration of ambient light stimuli to trigger lifestyle adaptations via modulation of central metabolite levels involved in diverse regulatory processes. Red light–sensing bacteriophytochromes are attractive targets for the development of innovative optogenetic tools because of their natural modularity of coupling with diverse functionalities and the natural availability of the light-absorbing biliverdin chromophore in animal tissues. However, a rational design of such tools is complicated by the poor understanding of molecular mechanisms of light signal transduction over long distances—from the site of photon absorption to the active site of downstream enzymatic effectors. Here we show how swapping structural elements between two bacteriophytochrome homologs provides additional insight into light signal integration and effector regulation, involving a fine-tuned interplay of important structural elements of the sensor, as well as the sensor–effector linker. Facilitated by the availability of structural information of inhibited and activated full-length structures of one of the two homologs (Idiomarina species A28L phytochrome-activated diguanylyl cyclase (IsPadC)) and characteristic differences in photoresponses of the two homologs, we identify an important cross-talk between the N-terminal segment, containing the covalent attachment site of the chromophore, and the PHY-tongue region. Moreover, we highlight how these elements influence the dynamic range of photoactivation and how activation can be improved to light/dark ratios of ∼800-fold by reducing basal dark-state activities at the same time as increasing conversion in the light state. This will enable future optimization of optogenetic tools aiming at a direct allosteric regulation of enzymatic effectors.
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Affiliation(s)
- Geoffrey Gourinchas
- From the Institute of Biochemistry, Graz University of Technology, 8010 Graz, Austria and
| | - Uršula Vide
- From the Institute of Biochemistry, Graz University of Technology, 8010 Graz, Austria and
| | - Andreas Winkler
- From the Institute of Biochemistry, Graz University of Technology, 8010 Graz, Austria and .,BioTechMed-Graz, 8010 Graz, Austria
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8
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Li X, Hu D, Xie Y, Lan Z. Analysis of trajectory similarity and configuration similarity in on-the-fly surface-hopping simulation on multi-channel nonadiabatic photoisomerization dynamics. J Chem Phys 2018; 149:244104. [DOI: 10.1063/1.5048049] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Affiliation(s)
- Xusong Li
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Sino-Danish Center for Education and Research/Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Deping Hu
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu Xie
- The Environmental Research Institute, MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China
| | - Zhenggang Lan
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
- Sino-Danish Center for Education and Research/Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, China
- The Environmental Research Institute, MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China
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9
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Gourinchas G, Heintz U, Winkler A. Asymmetric activation mechanism of a homodimeric red light-regulated photoreceptor. eLife 2018; 7:34815. [PMID: 29869984 PMCID: PMC6005682 DOI: 10.7554/elife.34815] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 06/03/2018] [Indexed: 12/18/2022] Open
Abstract
Organisms adapt to environmental cues using diverse signaling networks. In order to sense and integrate light for regulating various biological functions, photoreceptor proteins have evolved in a modular way. This modularity is targeted in the development of optogenetic tools enabling the control of cellular events with high spatiotemporal precision. However, the limited understanding of signaling mechanisms impedes the rational design of innovative photoreceptor-effector couples. Here, we reveal molecular details of signal transduction in phytochrome-regulated diguanylyl cyclases. Asymmetric structural changes of the full-length homodimer result in a functional heterodimer featuring two different photoactivation states. Structural changes around the cofactors result in a quasi-translational rearrangement of the distant coiled-coil sensor-effector linker. Eventually, this regulates enzymatic activity by modulating the dimer interface of the output domains. Considering the importance of phytochrome heterodimerization in plant signaling, our mechanistic details of asymmetric photoactivation in a bacterial system reveal novel aspects of the evolutionary adaptation of phytochromes.
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Affiliation(s)
| | - Udo Heintz
- Max Planck Institute for Medical Research, Heidelberg, Germany
| | - Andreas Winkler
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
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10
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Gozem S, Luk HL, Schapiro I, Olivucci M. Theory and Simulation of the Ultrafast Double-Bond Isomerization of Biological Chromophores. Chem Rev 2017; 117:13502-13565. [DOI: 10.1021/acs.chemrev.7b00177] [Citation(s) in RCA: 175] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Samer Gozem
- Department
of Chemistry, Georgia State University, Atlanta, Georgia 30302, United States
| | - Hoi Ling Luk
- Chemistry
Department, Bowling Green State University, Overman Hall, Bowling Green, Ohio 43403, United States
| | - Igor Schapiro
- Fritz
Haber Center for Molecular Dynamics, Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Massimo Olivucci
- Chemistry
Department, Bowling Green State University, Overman Hall, Bowling Green, Ohio 43403, United States
- Dipartimento
di Biotecnologie, Chimica e Farmacia, Università di Siena, via A. Moro
2, 53100 Siena, Italy
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11
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Takiden A, Velazquez-Escobar F, Dragelj J, Woelke AL, Knapp EW, Piwowarski P, Bart F, Hildebrandt P, Mroginski MA. Structural and Vibrational Characterization of the Chromophore Binding Site of Bacterial Phytochrome Agp1. Photochem Photobiol 2017; 93:713-723. [DOI: 10.1111/php.12737] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 12/16/2016] [Indexed: 12/13/2022]
Affiliation(s)
- Aref Takiden
- Institut für Chemie; Technische Universität Berlin; Berlin Germany
| | | | - Jovan Dragelj
- Institut für Chemie und Biochemie; Freie Universität Berlin; Berlin Germany
| | - Anna Lena Woelke
- Institut für Chemie und Biochemie; Freie Universität Berlin; Berlin Germany
| | - Ernst-Walter Knapp
- Institut für Chemie und Biochemie; Freie Universität Berlin; Berlin Germany
| | - Patrick Piwowarski
- Institute of Medical Physics and Biophysics; Charité-Medical University Berlin; Berlin Germany
| | - Franz Bart
- Institute of Medical Physics and Biophysics; Charité-Medical University Berlin; Berlin Germany
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12
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Velazquez Escobar F, Lang C, Takiden A, Schneider C, Balke J, Hughes J, Alexiev U, Hildebrandt P, Mroginski MA. Protonation-Dependent Structural Heterogeneity in the Chromophore Binding Site of Cyanobacterial Phytochrome Cph1. J Phys Chem B 2016; 121:47-57. [DOI: 10.1021/acs.jpcb.6b09600] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Francisco Velazquez Escobar
- Institut
für Chemie, Technische Universität Berlin, Sekr. PC 14, Straße des 17. Juni 135, D-10623 Berlin, Germany
| | - Christina Lang
- Plant
Physiology, Justus-Liebig University Gießen, Senckenbergstrasse 3, D-35390 Giessen, Germany
| | - Aref Takiden
- Plant
Physiology, Justus-Liebig University Gießen, Senckenbergstrasse 3, D-35390 Giessen, Germany
| | - Constantin Schneider
- Institut
für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Jens Balke
- Institut
für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Jon Hughes
- Plant
Physiology, Justus-Liebig University Gießen, Senckenbergstrasse 3, D-35390 Giessen, Germany
| | - Ulrike Alexiev
- Institut
für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Peter Hildebrandt
- Institut
für Chemie, Technische Universität Berlin, Sekr. PC 14, Straße des 17. Juni 135, D-10623 Berlin, Germany
| | - Maria Andrea Mroginski
- Institut
für Chemie, Technische Universität Berlin, Sekr. PC 14, Straße des 17. Juni 135, D-10623 Berlin, Germany
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13
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Velazquez Escobar F, von Stetten D, Günther-Lütkens M, Keidel A, Michael N, Lamparter T, Essen LO, Hughes J, Gärtner W, Yang Y, Heyne K, Mroginski MA, Hildebrandt P. Conformational heterogeneity of the Pfr chromophore in plant and cyanobacterial phytochromes. Front Mol Biosci 2015. [PMID: 26217669 PMCID: PMC4498102 DOI: 10.3389/fmolb.2015.00037] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Phytochromes are biological photoreceptors that can be reversibly photoconverted between a dark and photoactivated state. The underlying reaction sequences are initiated by the photoisomerization of the tetrapyrrole cofactor, which in plant and cyanobacterial phytochromes are a phytochromobilin (PΦB) and a phycocyanobilin (PCB), respectively. The transition between the two states represents an on/off-switch of the output module activating or deactivating downstream physiological processes. In addition, the photoactivated state, i.e., Pfr in canonical phytochromes, can be thermally reverted to the dark state (Pr). The present study aimed to improve our understanding of the specific reactivity of various PΦB- and PCB-binding phytochromes in the Pfr state by analysing the cofactor structure by vibrational spectroscopic techniques. Resonance Raman (RR) spectroscopy revealed two Pfr conformers (Pfr-I and Pfr-II) forming a temperature-dependent conformational equilibrium. The two sub-states—found in all phytochromes studied, albeit with different relative contributions—differ in structural details of the C-D and A-B methine bridges. In the Pfr-I sub-state the torsion between the rings C and D is larger by ca. 10° compared to Pfr-II. This structural difference is presumably related to different hydrogen bonding interactions of ring D as revealed by time-resolved IR spectroscopic studies of the cyanobacterial phytochrome Cph1. The transitions between the two sub-states are evidently too fast (i.e., nanosecond time scale) to be resolved by NMR spectroscopy which could not detect a structural heterogeneity of the chromophore in Pfr. The implications of the present findings for the dark reversion of the Pfr state are discussed.
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Affiliation(s)
| | | | | | - Anke Keidel
- Institut für Chemie, Technische Universität Berlin Berlin, Germany
| | - Norbert Michael
- Institut für Chemie, Technische Universität Berlin Berlin, Germany
| | - Tilman Lamparter
- Botanisches Institut, Karlsruher Institut für Technologie Karlsruhe, Germany
| | | | - Jon Hughes
- Institut für Pflanzenphysiologie, Justus Liebig University Gießen, Germany
| | - Wolfgang Gärtner
- Max-Planck-Institut für Chemische Energiekonversion Mülheim, Germany
| | - Yang Yang
- Institut für Experimentalphysik, Freie Universität Berlin Berlin, Germany
| | - Karsten Heyne
- Institut für Experimentalphysik, Freie Universität Berlin Berlin, Germany
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14
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Zhuang X, Wang J, Lan Z. Tracking of the Molecular Motion in the Primary Event of Photoinduced Reactions of a Phytochromobilin Model. J Phys Chem B 2013; 117:15976-86. [DOI: 10.1021/jp408799b] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Xuhui Zhuang
- Key
Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
- The
Qingdao Key Lab of Solar Energy Utilization and Energy Storage Technology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, P. R. China
| | - Jun Wang
- Key
Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
- The
Qingdao Key Lab of Solar Energy Utilization and Energy Storage Technology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, P. R. China
| | - Zhenggang Lan
- Key
Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
- The
Qingdao Key Lab of Solar Energy Utilization and Energy Storage Technology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, P. R. China
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15
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Nieder JB, Stojković EA, Moffat K, Forest KT, Lamparter T, Bittl R, Kennis JTM. Pigment–Protein Interactions in Phytochromes Probed by Fluorescence Line Narrowing Spectroscopy. J Phys Chem B 2013; 117:14940-50. [DOI: 10.1021/jp409110q] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Jana B. Nieder
- Fachbereich
Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Emina A. Stojković
- Department of Biochemistry and Molecular Biology, Center for Advanced
Radiation Sources, and Institute for Biophysical Dynamics, University of Chicago, 920 East 58th Street, Chicago, Illinois 60637, United States
| | - Keith Moffat
- Department of Biochemistry and Molecular Biology, Center for Advanced
Radiation Sources, and Institute for Biophysical Dynamics, University of Chicago, 920 East 58th Street, Chicago, Illinois 60637, United States
| | - Katrina T. Forest
- Department of Bacteriology, University of Wisconsin—Madison, 1550 Linden Drive, Madison, Wisconsin 53706, United States
| | - Tilman Lamparter
- Botany
1, KIT - Karlsruhe Institute of Technology, Kaiserstrasse 2, D 76131 Karlsruhe, Germany
| | - Robert Bittl
- Fachbereich
Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - John T. M. Kennis
- Department of Physics and Astronomy, Biophysics Section, VU University Amsterdam, De Boelelaan 1081, NL-1081 HV Amsterdam, The Netherlands
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16
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Salewski J, Escobar FV, Kaminski S, von Stetten D, Keidel A, Rippers Y, Michael N, Scheerer P, Piwowarski P, Bartl F, Frankenberg-Dinkel N, Ringsdorf S, Gärtner W, Lamparter T, Mroginski MA, Hildebrandt P. Structure of the biliverdin cofactor in the Pfr state of bathy and prototypical phytochromes. J Biol Chem 2013; 288:16800-16814. [PMID: 23603902 DOI: 10.1074/jbc.m113.457531] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Phytochromes act as photoswitches between the red- and far-red absorbing parent states of phytochromes (Pr and Pfr). Plant phytochromes display an additional thermal conversion route from the physiologically active Pfr to Pr. The same reaction pattern is found in prototypical biliverdin-binding bacteriophytochromes in contrast to the reverse thermal transformation in bathy bacteriophytochromes. However, the molecular origin of the different thermal stabilities of the Pfr states in prototypical and bathy bacteriophytochromes is not known. We analyzed the structures of the chromophore binding pockets in the Pfr states of various bathy and prototypical biliverdin-binding phytochromes using a combined spectroscopic-theoretical approach. For the Pfr state of the bathy phytochrome from Pseudomonas aeruginosa, the very good agreement between calculated and experimental Raman spectra of the biliverdin cofactor is in line with important conclusions of previous crystallographic analyses, particularly the ZZEssa configuration of the chromophore and its mode of covalent attachment to the protein. The highly homogeneous chromophore conformation seems to be a unique property of the Pfr states of bathy phytochromes. This is in sharp contrast to the Pfr states of prototypical phytochromes that display conformational equilibria between two sub-states exhibiting small structural differences at the terminal methine bridges A-B and C-D. These differences may mainly root in the interactions of the cofactor with the highly conserved Asp-194 that occur via its carboxylate function in bathy phytochromes. The weaker interactions via the carbonyl function in prototypical phytochromes may lead to a higher structural flexibility of the chromophore pocket opening a reaction channel for the thermal (ZZE → ZZZ) Pfr to Pr back-conversion.
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Affiliation(s)
- Johannes Salewski
- Institut für Chemie, Technische Universität Berlin, Sekr. PC 14, Strasse des 17. Juni 135, D-10623 Berlin, Germany
| | - Francisco Velazquez Escobar
- Institut für Chemie, Technische Universität Berlin, Sekr. PC 14, Strasse des 17. Juni 135, D-10623 Berlin, Germany
| | - Steve Kaminski
- Institut für Chemie, Technische Universität Berlin, Sekr. PC 14, Strasse des 17. Juni 135, D-10623 Berlin, Germany
| | - David von Stetten
- Institut für Chemie, Technische Universität Berlin, Sekr. PC 14, Strasse des 17. Juni 135, D-10623 Berlin, Germany; Structural Biology Group, European Synchrotron Radiation Facility, 38043 Grenoble, France
| | - Anke Keidel
- Institut für Chemie, Technische Universität Berlin, Sekr. PC 14, Strasse des 17. Juni 135, D-10623 Berlin, Germany
| | - Yvonne Rippers
- Institut für Chemie, Technische Universität Berlin, Sekr. PC 14, Strasse des 17. Juni 135, D-10623 Berlin, Germany
| | - Norbert Michael
- Institut für Chemie, Technische Universität Berlin, Sekr. PC 14, Strasse des 17. Juni 135, D-10623 Berlin, Germany
| | - Patrick Scheerer
- Institute of Medical Physics and Biophysics (CCO), D-10117 Berlin, Germany; AG Protein X-ray Crystallography, D-10117 Berlin, Germany
| | - Patrick Piwowarski
- Institute of Medical Physics and Biophysics (CCO), D-10117 Berlin, Germany; AG Spectroscopy, Charité-University Medicine Berlin, Charitéplatz 1, D-10117 Berlin, Germany
| | - Franz Bartl
- Institute of Medical Physics and Biophysics (CCO), D-10117 Berlin, Germany; AG Spectroscopy, Charité-University Medicine Berlin, Charitéplatz 1, D-10117 Berlin, Germany
| | - Nicole Frankenberg-Dinkel
- AG Physiologie der Mikroorganismen, Ruhr-Universität Bochum, Universitätsstrasse 150, D-44780 Bochum, Germany
| | - Simone Ringsdorf
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, D-45470 Mülheim, Germany
| | - Wolfgang Gärtner
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, D-45470 Mülheim, Germany
| | - Tilman Lamparter
- Institut für Allgemeine Botanik, Karlsruher Institut für Technologie, Kaiserstrasse 2, D-76131 Karlsruhe, Germany
| | - Maria Andrea Mroginski
- Institut für Chemie, Technische Universität Berlin, Sekr. PC 14, Strasse des 17. Juni 135, D-10623 Berlin, Germany.
| | - Peter Hildebrandt
- Institut für Chemie, Technische Universität Berlin, Sekr. PC 14, Strasse des 17. Juni 135, D-10623 Berlin, Germany.
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Gärtner W. Kurt Schaffner: from organic photochemistry to photobiology. Photochem Photobiol Sci 2012; 11:872-80. [DOI: 10.1039/c2pp05405a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Elucidating photoinduced structural changes in phytochromes by the combined application of resonance Raman spectroscopy and theoretical methods. J Mol Struct 2011. [DOI: 10.1016/j.molstruc.2011.02.038] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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19
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Mroginski MA, Kaminski S, von Stetten D, Ringsdorf S, Gärtner W, Essen LO, Hildebrandt P. Structure of the chromophore binding pocket in the Pr state of plant phytochrome phyA. J Phys Chem B 2010; 115:1220-31. [PMID: 21192668 DOI: 10.1021/jp108265h] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A homology structural model was generated for plant phytochrome phyA utilizing the crystal structure of the sensory module of cyanobacterial phytochrome Cph1 (Cph1Δ2). As chromophores, either the native phytochromobilin cofactor (PΦB) or phycocyanobilin (PCB), the natural cofactor in Cph1, was incorporated. These homology models were further optimized by molecular dynamics (MD) simulations revealing a satisfying overall agreement with the crystal structure of Cph1Δ2. Notable differences in the PΦB adduct of phyA result from a restructuring of the small helical segment α(7) that leads to displacements of a few amino acids away from the cofactor. This repositioning of residues also include aspartate 218 such that, instead of its carbonyl function as in Cph1Δ2, an additional water molecule forms hydrogen bonds with the ring B and C NH groups. To validate the phyA structural model in the chromophore binding pocket, Raman spectra of the cofactor were calculated by means of the quantum mechanics/molecular mechanics (QM/MM) hybrid methodology and compared with the experimental resonance Raman (RR) spectra. The satisfactory overall agreement between calculated and experimental spectra is taken as an indication for the good quality of the structural model. Moreover, the methine bridge stretching modes and the effects of isotopic labeling at selected positions of the chromophore are very well reproduced to allow confirming even details of the methine bridge geometry as predicted by the homology model. Specifically, it is demonstrated that the experimental RR spectra are consistent with a torsional angle of ring D with respect to ring C that is distinctly higher for phyA-PCB (45°) and phyA-PΦB (42°) than for Cph1Δ2 (30°). Raman spectra calculated from different points of the MD trajectory display variations of the mode frequencies and intensities reflecting the structural fluctuations from snapshot to snapshot. The snapshot spectrum of the lowest energy structure and the sum of all snapshot spectra afford an equally good description of the experimental data. Particularly large variations between the snapshots are noted for the N-H in-plane bending mode of the pyrrole rings B and C, which reflect alterations of the hydrogen bond interactions brought about by fluctuations of water molecules in the cofactor cavity. This overestimation of the water molecule mobility is a consequence of the deficiency of the current QM/MM methodology that, due to the lack of appropriate protein force fields, cannot adequately account for the electrostatics in the cofactor pocket.
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Piwowarski P, Ritter E, Hofmann KP, Hildebrandt P, von Stetten D, Scheerer P, Michael N, Lamparter T, Bartl F. Light-induced activation of bacterial phytochrome Agp1 monitored by static and time-resolved FTIR spectroscopy. Chemphyschem 2010; 11:1207-14. [PMID: 20333618 DOI: 10.1002/cphc.200901008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Phytochromes, which regulate many biological processes in plants, bacteria, and fungi, can exist in two stable states, Pr and Pfr, that can be interconverted by light, via a number of intermediates such as meta-Rc. Herein we employ FTIR spectroscopy to study the Pr-to-Pfr conversion of the bacteriophytochrome Agp1 from Agrobacterium tumefaciens. Static FTIR Pfr/Pr and meta-Rc/Pr difference spectra are disentangled in terms of cofactor and protein structural changes. Guided by DFT calculations on cofactor models, the chromophore conformational changes can be grouped into structural adjustments of the cofactor-protein interactions localized in the C-D dipyrrole moiety, that is, the photoisomerisation site, and in the A-B dipyrrole moiety including the protein attachment site. Whereas changes at the C and D rings appear to be largely completed in the meta-Rc state, the structural changes in the A-B unit occur during the transition from meta-Rc to Pfr, concomitant with the main protein structural changes, as demonstrated by static and time-resolved FTIR difference spectroscopy. We employ this technique to monitor, for the first time, the dynamics of the photocycle of phytochrome on the millisecond timescale. By extending the studies to genetically engineered protein variants of Agp1, we further demonstrate that H250 and D197 as well as the PHY domain are essential for formation of the Pfr state. Based on the IR spectroscopic and available crystallographic data we discuss the role of critical amino acid residues for the protein-cofactor interactions during the photoinduced reaction cycle.
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Affiliation(s)
- Patrick Piwowarski
- Institut für Medizinische Physik und Biophysik, Charité, Universitätsmedizin Berlin, Charitéplatz 1, 10098 Berlin, Germany
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21
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Bongards C, Gärtner W. The role of the chromophore in the biological photoreceptor phytochrome: an approach using chemically synthesized tetrapyrroles. Acc Chem Res 2010; 43:485-95. [PMID: 20055450 DOI: 10.1021/ar800133x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In plants and bacteria, phytochromes serve as light-inducible, red-/far-red light sensitive photoreceptors that control a wide range of photomorphogenetic processes. Phytochromes comprise a protein moiety and a covalently bound bilin chromophore. Bilins are open-chain tetrapyrrole compounds that derive biosynthetically from ubiquitous porphyrins. The investigations of phytochromes reveal that precise interactions between the protein moiety and its bilin chromophore are essential for the proper functioning of this photoreceptor; accordingly, synthetic manipulation of the parts is an important method for studying the whole. Although variations in the protein structure are readily accomplished by routine mutagenesis protocols, the generation of structurally modified bilins is a laborious, multistep process. Recent improvement in the synthesis of open-chain tetrapyrroles now permits the generation of novel, structurally modified (and even selectively isotope-labeled) chromophores. Furthermore, by using the capability of recombinant apo-phytochrome to bind the chromophore autocatalytically, researchers can now generate novel chromoproteins with modified functions. In the protein-bound state, the phytochrome chromophore is photoisomerized at one double bond, in the bridge between the last two of the four pyrrole rings (the C and D rings), generating the thermally stable, physiologically active P(fr) form. This conversion--photoisomerization from the form absorbing red light (P(r)) to the form absorbing far-red light (P(fr))--covers 12 orders of magnitude, from subpicoseconds to seconds. Such spectroscopic and kinetic studies yield a wealth of time-resolved spectral data, even more so, if proteins with changed sequence or chromophore structure are utilized. In particular, bilins with a changed substitution pattern at the photoisomerizing ring D have shed light on the chromophore-protein interactions during the photoisomerization. The mechanisms generating and stabilizing the light-induced P(fr) form of phytochromes are now seen in greater detail. On the other hand, the use of bilins with selective incorporation of stable isotopes identify light-induced conformational motions when studied by vibrational (FTIR and Raman) and NMR spectroscopy. In this Account, we present spectroscopic investigations that provide structural details in these biological photoreceptors with great precision and document the dynamics elicited by light excitation. This approach yields important information that complements the data deduced from crystal structure.
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Affiliation(s)
- Christian Bongards
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34−36, D-45470 Mülheim an der Ruhr, Germany
| | - Wolfgang Gärtner
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34−36, D-45470 Mülheim an der Ruhr, Germany
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22
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Mroginski MA, von Stetten D, Escobar FV, Strauss HM, Kaminski S, Scheerer P, Günther M, Murgida DH, Schmieder P, Bongards C, Gärtner W, Mailliet J, Hughes J, Essen LO, Hildebrandt P. Chromophore structure of cyanobacterial phytochrome Cph1 in the Pr state: reconciling structural and spectroscopic data by QM/MM calculations. Biophys J 2009; 96:4153-63. [PMID: 19450486 DOI: 10.1016/j.bpj.2009.02.029] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2008] [Revised: 01/21/2009] [Accepted: 02/05/2009] [Indexed: 10/20/2022] Open
Abstract
A quantum mechanics (QM)/molecular mechanics (MM) hybrid method was applied to the Pr state of the cyanobacterial phytochrome Cph1 to calculate the Raman spectra of the bound PCB cofactor. Two QM/MM models were derived from the atomic coordinates of the crystal structure. The models differed in the protonation site of His(260) in the chromophore-binding pocket such that either the delta-nitrogen (M-HSD) or the epsilon-nitrogen (M-HSE) carried a hydrogen. The optimized structures of the two models display small differences specifically in the orientation of His(260) with respect to the PCB cofactor and the hydrogen bond network at the cofactor-binding site. For both models, the calculated Raman spectra of the cofactor reveal a good overall agreement with the experimental resonance Raman (RR) spectra obtained from Cph1 in the crystalline state and in solution, including Cph1 adducts with isotopically labeled PCB. However, a distinctly better reproduction of important details in the experimental spectra is provided by the M-HSD model, which therefore may represent an improved structure of the cofactor site. Thus, QM/MM calculations of chromoproteins may allow for refining crystal structure models in the chromophore-binding pocket guided by the comparison with experimental RR spectra. Analysis of the calculated and experimental spectra also allowed us to identify and assign the modes that sensitively respond to chromophore-protein interactions. The most pronounced effect was noted for the stretching mode of the methine bridge A-B adjacent to the covalent attachment site of PCB. Due a distinct narrowing of the A-B methine bridge bond angle, this mode undergoes a large frequency upshift as compared with the spectrum obtained by QM calculations for the chromophore in vacuo. This protein-induced distortion of the PCB geometry is the main origin of a previous erroneous interpretation of the RR spectra based on QM calculations of the isolated cofactor.
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23
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Borucki B, Seibeck S, Heyn MP, Lamparter T. Characterization of the covalent and noncovalent adducts of Agp1 phytochrome assembled with biliverdin and phycocyanobilin by circular dichroism and flash photolysis. Biochemistry 2009; 48:6305-17. [PMID: 19496558 DOI: 10.1021/bi900436v] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The functional role of the covalent attachment of the bilin chromophores biliverdin (BV) and phycocyanobilin (PCB) was investigated for phytochrome Agp1 from Agrobacterium tumefaciens using circular dichroism (CD) and transient absorption spectroscopy. Covalent and noncovalent adducts with these chromophores were prepared by using wild-type (WT) Agp1 (covalent BV and noncovalent PCB binding), mutant C20A in which the covalent BV binding site is eliminated, and mutant V249C in which the covalent PCB binding site is introduced. While the CD spectra of the P(r) forms of all these photochromic adducts are qualitatively the same, the CD spectrum of the P(fr) form of the covalent PCB adduct is unique in having a positive rotational strength in the Q-band which we assign to the Z-E isomerization of the C-D methine bridge. In the three other adducts, the Q-band CD in the P(fr) state is almost zero, suggesting that upon photoconversion a negative contribution from an out-of-plane rotation of the A ring of the chromophore compensates for the positive contribution from ring D. The contribution from ring A is absent or strongly reduced in the shorter pi-conjugation system of the covalent PCB adduct. The results from CD spectroscopy are consistent with a uniform geometry of the bilin chromophore in the covalent and noncovalent adducts. Transient absorption spectroscopy showed that the spectral changes and the kinetics of the P(r) to P(fr) photoconversion are not substantially affected by the covalent attachment of BV and PCB. The kinetics in the BV and PCB adducts mainly differ in the formation of P(fr) that is accelerated by 2 orders of magnitude in the PCB adducts, whereas the sequence of spectral transitions and the associated proton transfer processes are quite similar. We conclude that the P(r) to P(fr) photoconversion in the BV and PCB adducts of Agp1 involves the same relaxation processes and is thus governed by specific protein-cofactor interactions rather than by the chemical structure of the chromophore or the mode of attachment. The strongly reduced photostability of the noncovalent BV adduct suggests that covalent attachment in native Agp1 phytochrome prevents irreversible photobleaching and stabilizes the chromophore. The N-terminal peptide segment including amino acids 2-19 is essential for covalent attachment of the chromophore but dispensable for the spectral and kinetic properties of Agp1.
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Affiliation(s)
- Berthold Borucki
- Biophysics Group, Department of Physics, Freie Universitat Berlin, Arnimallee 14, 14195 Berlin, Germany.
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24
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Durbeej B. On the primary event of phytochrome: quantum chemical comparison of photoreactions at C4, C10 and C15. Phys Chem Chem Phys 2009; 11:1354-61. [PMID: 19224036 DOI: 10.1039/b811813b] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Phytochromes are widespread photoreceptors responsive to red and far-red light that exist in two photochromic forms Pr (inactive) and Pfr (active). The Pr --> Pfr conversion proceeds through a series of events initiated by Z-->E photoisomerization of the tetrapyrrole chromophore, believed to occur at C15 of the methine bridge between rings C and D. Recent crystal structures show that ring D in Pr is less tightly packed by the protein than rings A, B and C, which should favor the C15 reaction over reactions at C4 (AB methine bridge) and C10 (BC). In the present work, quantum chemical methods are used to establish the intrinsic reactivity of the chromophore towards all three possible Z-->E isomerization events in the absence of steric effects and specific interactions with the protein. Using a level of theory that reproduces spectroscopic data with an accuracy of approximately 0.2 eV, it is demonstrated that isolated conditions allow the C10 photoreaction to substantially dominate. This finding suggests that the different degrees of ring-packing observed in the protein are crucial not only to facilitate a reaction at C15, but also to prevent an intrinsically more favorable reaction at C10 from taking place.
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Affiliation(s)
- Bo Durbeej
- Department of Chemistry, University of Siena, Via Aldo Moro 2, I-53100, Siena, Italy.
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25
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Schwinté P, Gärtner W, Sharda S, Mroginski MA, Hildebrandt P, Siebert F. The Photoreactions of Recombinant Phytochrome CphA from the CyanobacteriumCalothrixPCC7601: A Low-Temperature UV-Vis and FTIR Study. Photochem Photobiol 2009; 85:239-49. [DOI: 10.1111/j.1751-1097.2008.00426.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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26
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Matute RA, Contreras R, Pérez-Hernández G, González L. The Chromophore Structure of the Cyanobacterial Phytochrome Cph1 As Predicted by Time-Dependent Density Functional Theory. J Phys Chem B 2008; 112:16253-6. [DOI: 10.1021/jp807471e] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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27
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The structure of a complete phytochrome sensory module in the Pr ground state. Proc Natl Acad Sci U S A 2008; 105:14709-14. [PMID: 18799745 DOI: 10.1073/pnas.0806477105] [Citation(s) in RCA: 322] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Phytochromes are red/far-red photochromic biliprotein photoreceptors, which in plants regulate seed germination, stem extension, flowering time, and many other light effects. However, the structure/functional basis of the phytochrome photoswitch is still unclear. Here, we report the ground state structure of the complete sensory module of Cph1 phytochrome from the cyanobacterium Synechocystis 6803. Although the phycocyanobilin (PCB) chromophore is attached to Cys-259 as expected, paralleling the situation in plant phytochromes but contrasting to that in bacteriophytochromes, the ZZZssa conformation does not correspond to that expected from Raman spectroscopy. We show that the PHY domain, previously considered unique to phytochromes, is structurally a member of the GAF (cGMP phosphodiesterase/adenylyl cyclase/FhlA) family. Indeed, the tandem-GAF dumbbell revealed for phytochrome sensory modules is remarkably similar to the regulatory domains of cyclic nucleotide (cNMP) phosphodiesterases and adenylyl cyclases. A unique feature of the phytochrome structure is a long, tongue-like protrusion from the PHY domain that seals the chromophore pocket and stabilizes the photoactivated far-red-absorbing state (Pfr). The tongue carries a conserved PRxSF motif, from which an arginine finger points into the chromophore pocket close to ring D forming a salt bridge with a conserved aspartate residue. The structure that we present provides a framework for light-driven signal transmission in phytochromes.
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von Stetten D, Günther M, Scheerer P, Murgida DH, Mroginski MA, Krauss N, Lamparter T, Zhang J, Anstrom DM, Vierstra RD, Forest KT, Hildebrandt P. Chromophore heterogeneity and photoconversion in phytochrome crystals and solution studied by resonance Raman spectroscopy. Angew Chem Int Ed Engl 2008; 47:4753-5. [PMID: 18484576 DOI: 10.1002/anie.200705716] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- David von Stetten
- Institut für Chemie, Sekr. PC14, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany
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29
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Ulijasz AT, Cornilescu G, von Stetten D, Kaminski S, Mroginski MA, Zhang J, Bhaya D, Hildebrandt P, Vierstra RD. Characterization of two thermostable cyanobacterial phytochromes reveals global movements in the chromophore-binding domain during photoconversion. J Biol Chem 2008; 283:21251-66. [PMID: 18480055 PMCID: PMC3258942 DOI: 10.1074/jbc.m801592200] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2008] [Revised: 04/30/2008] [Indexed: 11/06/2022] Open
Abstract
Photointerconversion between the red light-absorbing (Pr) form and the far-red light-absorbing (Pfr) form is the central feature that allows members of the phytochrome (Phy) superfamily to act as reversible switches in light perception. Whereas the chromophore structure and surrounding binding pocket of Pr have been described, those for Pfr have remained enigmatic for various technical reasons. Here we describe a novel pair of Phys from two thermophilic cyanobacteria, Synechococcus sp. OS-A and OS-B', that overcome several of these limitations. Like other cyanobacterial Phys, SyA-Cph1 and SyB-Cph1 covalently bind the bilin phycocyanobilin via their cGMP phosphodiesterase/adenyl cyclase/FhlA (GAF) domains and then assume the photointerconvertible Pr and Pfr states with absorption maxima at 630 and 704 nm, respectively. However, they are naturally missing the N-terminal Per/Arndt/Sim domain common to others in the Phy superfamily. Importantly, truncations containing only the GAF domain are monomeric, photochromic, and remarkably thermostable. Resonance Raman and NMR spectroscopy show that all four pyrrole ring nitrogens of phycocyanobilin are protonated both as Pr and following red light irradiation, indicating that the GAF domain by itself can complete the Pr to Pfr photocycle. (1)H-(15)N two-dimensional NMR spectra of isotopically labeled preparations of the SyB-Cph1 GAF domain revealed that a number of amino acids change their environment during photoconversion of Pr to Pfr, which can be reversed by subsequent photoconversion back to Pr. Through three-dimensional NMR spectroscopy before and after light photoexcitation, it should now be possible to define the movements of the chromophore and binding pocket during photoconversion. We also generated a series of strongly red fluorescent derivatives of SyB-Cph1, which based on their small size and thermostability may be useful as cell biological reporters.
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Affiliation(s)
- Andrew T. Ulijasz
- Department of Genetics and
National Magnetic Resonance Facility,
University of Wisconsin, Madison, Wisconsin 53706, the
Technische Universität, D-10623
Berlin, Germany, and the Department of
Plant Biology, Carnegie Institution of Washington, Stanford, California
94305
| | - Gabriel Cornilescu
- Department of Genetics and
National Magnetic Resonance Facility,
University of Wisconsin, Madison, Wisconsin 53706, the
Technische Universität, D-10623
Berlin, Germany, and the Department of
Plant Biology, Carnegie Institution of Washington, Stanford, California
94305
| | - David von Stetten
- Department of Genetics and
National Magnetic Resonance Facility,
University of Wisconsin, Madison, Wisconsin 53706, the
Technische Universität, D-10623
Berlin, Germany, and the Department of
Plant Biology, Carnegie Institution of Washington, Stanford, California
94305
| | - Steve Kaminski
- Department of Genetics and
National Magnetic Resonance Facility,
University of Wisconsin, Madison, Wisconsin 53706, the
Technische Universität, D-10623
Berlin, Germany, and the Department of
Plant Biology, Carnegie Institution of Washington, Stanford, California
94305
| | - Maria Andrea Mroginski
- Department of Genetics and
National Magnetic Resonance Facility,
University of Wisconsin, Madison, Wisconsin 53706, the
Technische Universität, D-10623
Berlin, Germany, and the Department of
Plant Biology, Carnegie Institution of Washington, Stanford, California
94305
| | - Junrui Zhang
- Department of Genetics and
National Magnetic Resonance Facility,
University of Wisconsin, Madison, Wisconsin 53706, the
Technische Universität, D-10623
Berlin, Germany, and the Department of
Plant Biology, Carnegie Institution of Washington, Stanford, California
94305
| | - Devaki Bhaya
- Department of Genetics and
National Magnetic Resonance Facility,
University of Wisconsin, Madison, Wisconsin 53706, the
Technische Universität, D-10623
Berlin, Germany, and the Department of
Plant Biology, Carnegie Institution of Washington, Stanford, California
94305
| | - Peter Hildebrandt
- Department of Genetics and
National Magnetic Resonance Facility,
University of Wisconsin, Madison, Wisconsin 53706, the
Technische Universität, D-10623
Berlin, Germany, and the Department of
Plant Biology, Carnegie Institution of Washington, Stanford, California
94305
| | - Richard D. Vierstra
- Department of Genetics and
National Magnetic Resonance Facility,
University of Wisconsin, Madison, Wisconsin 53706, the
Technische Universität, D-10623
Berlin, Germany, and the Department of
Plant Biology, Carnegie Institution of Washington, Stanford, California
94305
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von Stetten D, Günther M, Scheerer P, Murgida D, Mroginski M, Krauß N, Lamparter T, Zhang J, Anstrom D, Vierstra R, Forest K, Hildebrandt P. Resonanz-Raman-spektroskopische Untersuchung der Chromophorheterogenität und Photokonversion in Phytochromkristallen und -lösungen. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200705716] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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FTIR study of the photoinduced processes of plant phytochrome phyA using isotope-labeled bilins and density functional theory calculations. Biophys J 2008; 95:1256-67. [PMID: 18390618 DOI: 10.1529/biophysj.108.131441] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Fourier transform infrared spectroscopy was used to analyze the chromophore structure in the parent states Pr and Pfr of plant phytochrome phyA and the respective photoproducts lumi-R and lumi-F. The spectra were obtained from phyA adducts assembled with either uniformly or selectively isotope-labeled phytochromobilin and phycocyanobilin. The interpretation of the experimental spectra is based on the spectra of chromophore models calculated by density functional theory. Global (13)C-labeling of the tetrapyrrole allows for the discrimination between chromophore and protein bands in the Fourier transform infrared difference spectra. All infrared difference spectra display a prominent difference band attributable to a stretching mode with large contributions from the methine bridge between the inner pyrrole rings (B-C stretching). Due to mode coupling, frequencies and isotopic shifts of this mode suggest that the Pr chromophore may adopt a distorted ZZZssa or ZZZasa geometry with a twisted A-B methine bridge. The transition to lumi-R is associated with only minor changes of the amide I bands indicating limited protein structural changes during the isomerization site of the C-D methine bridge. Major protein structural changes occur upon the transition to Pfr in which the chromophore adopts a ZZEssa or ZZEasa-like state. In addition, specific interactions with the protein alter the structure of the B-C methine bridge as concluded from the substantial downshift of the respective stretching mode. These interactions are removed during the photoreaction to lumi-F (ZZE-->ZZZ), which involves only small protein structural changes.
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Anders Borg O, Durbeej B. Which factors determine the acidity of the phytochromobilin chromophore of plant phytochrome? Phys Chem Chem Phys 2008; 10:2528-37. [PMID: 18446253 DOI: 10.1039/b719190a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Quantum chemical calculations aimed at identifying the factors controlling the acidity of phytochromobilin, the tetrapyrrole chromophore of the plant photoreceptor phytochrome, are reported. Phytochrome is converted from an inactive (Pr) to an active form (Pfr) through a series of events initiated by a Z --> E photoisomerization of phytochromobilin, forming the Lumi-R intermediate, and much controversy exists as to whether the protonation state of the chromophore (cationic in Pr with all nitrogens protonated) changes during the photoactivation. Here, relative ground (S0) and excited-state (S1) pKa s of all four pyrrole moieties of phytochromobilin in all 64 possible configurations with respect to the three methine bridges are calculated in a protein-like environment, using a recently benchmarked level of theory. Accordingly, the relationships between acidity and chromophore geometry and charge distribution, hydrogen bonding, and light absorption are investigated in some detail, and discussed in terms of possible mechanisms making a proton transfer reaction more probable along the Pr --> Pfr reaction than in the parent cationic Pr state. It is found that charge distribution in the cationic species, intra-molecular hydrogen bonding in the neutral, and hydrogen bonding with two highly conserved aspartate and histidine residues have a significant effect on the acidity, while overall chromophore geometry and electronic state are less important factors. Furthermore, based on the calculations, two processes that may facilitate a proton transfer by substantially lowering the pKa s relative to their Pr values are identified: (i) a thermal Z,anti --> Z,syn isomerization at C5, occurring after formation of Lumi-R; (ii) a perturbation of the hydrogen bonding network which in Pr comprises the nitrogens of pyrroles A, B and C and the two aspartate and histidine residues.
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Affiliation(s)
- O Anders Borg
- Department of Quantum Chemistry, Uppsala University, Box 518, S-75120, Uppsala, Sweden
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Hahn J, Kühne R, Schmieder P. Solution-State15N NMR Spectroscopic Study of α-C-Phycocyanin: Implications for the Structure of the Chromophore-Binding Pocket of the Cyanobacterial Phytochrome Cph1. Chembiochem 2007; 8:2249-55. [DOI: 10.1002/cbic.200700256] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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