1
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Zheng R, Feng Y, Kong L, Wu X, Zhou J, Zhang L, Liu S. Blue-light irradiation induced partial nitrification. WATER RESEARCH 2024; 254:121381. [PMID: 38442606 DOI: 10.1016/j.watres.2024.121381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 12/08/2023] [Accepted: 02/24/2024] [Indexed: 03/07/2024]
Abstract
The role of ray radiation from the sunlight acting on organisms has long-term been investigated. However, how the light with different wavelengths affects nitrification and the involved nitrifiers are still elusive. Here, we found more than 60 % of differentially expressed genes (DEGs) in nitrifiers were observed under irradiation of blue light with wavelengths of 440-480 nm, which were 13.4 % and 20.3 % under red light and white light irradiation respectively. Blue light was more helpful to achieve partial nitrification rather than white light or red light, where ammonium oxidization by ammonia-oxidizing archaea (AOA) with the increased relative abundance from 8.6 % to 14.2 % played a vital role. This was further evidenced by the enhanced TCA cycle, reactive oxygen species (ROS) scavenge and DNA repair capacity in AOA under blue-light irradiation. In contrast, nitrite-oxidizing bacteria (NOB) was inhibited severely to achieve partial nitrification, and the newly discovered encoded blue light photoreceptor proteins made them more sensitive to blue light and hindered cell activity. Ammonia-oxidizing bacteria (AOB) expressed genes for DNA repair capacity under blue-light irradiation, which ensured their tiny impact by light irradiation. This study provided valuable insights into the photosensitivity mechanism of nitrifiers and shed light on the diverse regulatory by light with different radiation wavelengths in artificial systems, broadening our comprehension of the nitrogen cycle on earth.
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Affiliation(s)
- Ru Zheng
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Beijing 100871, China
| | - Yiming Feng
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Beijing 100871, China
| | - Lingrui Kong
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Beijing 100871, China
| | - Xiaogang Wu
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Beijing 100871, China
| | - Jianhang Zhou
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Beijing 100871, China
| | - Liguo Zhang
- School of Environmental and Resource Sciences, Shanxi University, Taiyuan, 030006, China.
| | - Sitong Liu
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Beijing 100871, China.
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2
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Tolentino Collado J, Bodis E, Pasitka J, Szucs M, Fekete Z, Kis-Bicskei N, Telek E, Pozsonyi K, Kapetanaki SM, Greetham G, Tonge PJ, Meech SR, Lukacs A. Single Amino Acid Mutation Decouples Photochemistry of the BLUF Domain from the Enzymatic Function of OaPAC and Drives the Enzyme to a Switched-on State. J Mol Biol 2024; 436:168312. [PMID: 37827329 DOI: 10.1016/j.jmb.2023.168312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 09/29/2023] [Accepted: 10/05/2023] [Indexed: 10/14/2023]
Abstract
Photoactivated adenylate cyclases (PACs) are light-activated enzymes that combine a BLUF (blue-light using flavin) domain and an adenylate cyclase domain that are able to increase the levels of the important second messenger cAMP (cyclic adenosine monophosphate) upon blue-light excitation. The light-induced changes in the BLUF domain are transduced to the adenylate cyclase domain via a mechanism that has not yet been established. One critical residue in the photoactivation mechanism of BLUF domains, present in the vicinity of the flavin is the glutamine amino acid close to the N5 of the flavin. The role of this residue has been investigated extensively both experimentally and theoretically. However, its role in the activity of the photoactivated adenylate cyclase, OaPAC has never been addressed. In this work, we applied ultrafast transient visible and infrared spectroscopies to study the photochemistry of the Q48E OaPAC mutant. This mutation altered the primary electron transfer process and switched the enzyme into a permanent 'on' state, able to increase the cAMP levels under dark conditions compared to the cAMP levels of the dark-adapted state of the wild-type OaPAC. Differential scanning calorimetry measurements point to a less compact structure for the Q48E OaPAC mutant. The ensemble of these findings provide insight into the important elements in PACs and how their fine tuning may help in the design of optogenetic devices.
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Affiliation(s)
| | - Emoke Bodis
- Department of Biophysics, Medical School, University of Pecs, Szigeti str. 12, 7624 Pecs, Hungary
| | - Jonatan Pasitka
- Department of Biophysics, Medical School, University of Pecs, Szigeti str. 12, 7624 Pecs, Hungary
| | - Mihaly Szucs
- Department of Biophysics, Medical School, University of Pecs, Szigeti str. 12, 7624 Pecs, Hungary
| | - Zsuzsanna Fekete
- Department of Biophysics, Medical School, University of Pecs, Szigeti str. 12, 7624 Pecs, Hungary
| | - Nikolett Kis-Bicskei
- Department of Biophysics, Medical School, University of Pecs, Szigeti str. 12, 7624 Pecs, Hungary
| | - Elek Telek
- Department of Biophysics, Medical School, University of Pecs, Szigeti str. 12, 7624 Pecs, Hungary
| | - Kinga Pozsonyi
- Department of Biophysics, Medical School, University of Pecs, Szigeti str. 12, 7624 Pecs, Hungary
| | - Sofia M Kapetanaki
- Department of Biophysics, Medical School, University of Pecs, Szigeti str. 12, 7624 Pecs, Hungary
| | - Greg Greetham
- Central Laser Facility, Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot OX11 0QX, UK
| | - Peter J Tonge
- Department of Chemistry, Stony Brook University, New York 11794, United States.
| | - Stephen R Meech
- School of Chemistry, University of East Anglia, Norwich, NR4 7TJ, UK.
| | - Andras Lukacs
- Department of Biophysics, Medical School, University of Pecs, Szigeti str. 12, 7624 Pecs, Hungary.
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3
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Nakasone Y, Murakami H, Tokonami S, Oda T, Terazima M. Time-resolved study on signaling pathway of photoactivated adenylate cyclase and its nonlinear optical response. J Biol Chem 2023; 299:105285. [PMID: 37742920 PMCID: PMC10634658 DOI: 10.1016/j.jbc.2023.105285] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/06/2023] [Accepted: 09/18/2023] [Indexed: 09/26/2023] Open
Abstract
Photoactivated adenylate cyclases (PACs) are multidomain BLUF proteins that regulate the cellular levels of cAMP in a light-dependent manner. The signaling route and dynamics of PAC from Oscillatoria acuminata (OaPAC), which consists of a light sensor BLUF domain, an adenylate cyclase domain, and a connector helix (α3-helix), were studied by detecting conformational changes in the protein moiety. Although circular dichroism and small-angle X-ray scattering measurements did not show significant changes upon light illumination, the transient grating method successfully detected light-induced changes in the diffusion coefficient (diffusion-sensitive conformational change (DSCC)) of full-length OaPAC and the BLUF domain with the α3-helix. DSCC of full-length OaPAC was observed only when both protomers in a dimer were photoconverted. This light intensity dependence suggests that OaPAC is a cyclase with a nonlinear light intensity response. The enzymatic activity indeed nonlinearly depends on light intensity, that is, OaPAC is activated under strong light conditions. It was also found that both DSCC and enzymatic activity were suppressed by a mutation in the W90 residue, indicating the importance of the highly conserved Trp in many BLUF domains for the function. Based on these findings, a reaction scheme was proposed together with the reaction dynamics.
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Affiliation(s)
- Yusuke Nakasone
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Hiroto Murakami
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Shunrou Tokonami
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Takashi Oda
- Department of Life Science and Research Center for Life Science, College of Science, Rikkyo University, Tokyo, Japan
| | - Masahide Terazima
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan.
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4
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Raics K, Pirisi K, Zhuang B, Fekete Z, Kis-Bicskei N, Pecsi I, Ujfalusi KP, Telek E, Li Y, Collado JT, Tonge PJ, Meech SR, Vos MH, Bodis E, Lukacs A. Photocycle alteration and increased enzymatic activity in genetically modified photoactivated adenylate cyclase OaPAC. J Biol Chem 2023; 299:105056. [PMID: 37468104 PMCID: PMC10448171 DOI: 10.1016/j.jbc.2023.105056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/30/2023] [Accepted: 07/11/2023] [Indexed: 07/21/2023] Open
Abstract
Photoactivated adenylate cyclases (PACs) are light activated enzymes that combine blue light sensing capacity with the ability to convert ATP to cAMP and pyrophosphate (PPi) in a light-dependent manner. In most of the known PACs blue light regulation is provided by a blue light sensing domain using flavin which undergoes a structural reorganization after blue-light absorption. This minor structural change then is translated toward the C-terminal of the protein, inducing a larger conformational change that results in the ATP conversion to cAMP. As cAMP is a key second messenger in numerous signal transduction pathways regulating various cellular functions, PACs are of great interest in optogenetic studies. The optimal optogenetic device must be "silent" in the dark and highly responsive upon light illumination. PAC from Oscillatoria acuminata is a very good candidate as its basal activity is very small in the dark and the conversion rates increase 20-fold upon light illumination. We studied the effect of replacing D67 to N, in the blue light using flavin domain. This mutation was found to accelerate the primary electron transfer process in the photosensing domain of the protein, as has been predicted. Furthermore, it resulted in a longer lived signaling state, which was formed with a lower quantum yield. Our studies show that the overall effects of the D67N mutation lead to a slightly higher conversion of ATP to cAMP, which points in the direction that by fine tuning the kinetic properties more responsive PACs and optogenetic devices can be generated.
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Affiliation(s)
- Katalin Raics
- Department of Biophysics, Medical School, University of Pecs, Pecs, Hungary
| | - Katalin Pirisi
- Department of Biophysics, Medical School, University of Pecs, Pecs, Hungary
| | - Bo Zhuang
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, Palaiseau, France
| | - Zsuzsanna Fekete
- Department of Biophysics, Medical School, University of Pecs, Pecs, Hungary
| | | | - Ildiko Pecsi
- Department of Biophysics, Medical School, University of Pecs, Pecs, Hungary
| | | | - Elek Telek
- Department of Biophysics, Medical School, University of Pecs, Pecs, Hungary
| | - Yin Li
- Department of Physics, School of Physics and Materials Science, Nanchang University, Nanchang City, China
| | | | - Peter J Tonge
- Department of Chemistry, Stony Brook University, New York, USA
| | | | - Marten H Vos
- Laboratoire d'Optique et Biosciences, Ecole Polytechnique, Palaiseau, France
| | - Emoke Bodis
- Department of Biophysics, Medical School, University of Pecs, Pecs, Hungary.
| | - Andras Lukacs
- Department of Biophysics, Medical School, University of Pecs, Pecs, Hungary.
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5
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Tokonami S, Nakasone Y, Terazima M. Effects of N- and C-terminal regions on oligomeric formation of blue light sensor protein SyPixD. Protein Sci 2023; 32:e4658. [PMID: 37184370 PMCID: PMC10211260 DOI: 10.1002/pro.4658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/08/2023] [Accepted: 05/10/2023] [Indexed: 05/16/2023]
Abstract
A sensor of blue-light using flavin adenine dinucleotide (BLUF) is a typical blue light photoreceptor domain that is found in many photosensor proteins in bacteria and some eukaryotic algae. SyPixD in Synechocystis is one of the well-studied BLUF proteins. In the dark state, it forms a decamer and, upon photoexcitation, a dissociation reaction takes place to yield dimers. Such change in the intermolecular interactions of the protomers is important for the biological function. The effect of the N- and C-terminal sequences on the stability of SyPixD oligomeric states and photoreactions of SyPixD were studied to understand how the oligomeric form is maintained with weak interaction. It was found that a few residues that frequently persist at the N-terminus after removing a tag for purification are sensitive to the stability of the decamer structure. Even two or three residues at the N-terminus considerably reduces decamer stability, whereas four or more residues completely prevent decamer formation. Unexpectedly, truncating C-terminal sequences, which locate far from any protomer interface and of which structure is undetermined in crystal structure, also destabilizes the decamer structure. This destabilization is also apparent from the dissociation reaction dynamics detected by the transient grating and transient absorption measurements. The dissociation reaction is faster and the yield increases when the C-terminus does not contain seven amino acid residues. Photoexcitation induces a conformational change in the C-terminus of the decamer but not the dimer.
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Affiliation(s)
- Shunrou Tokonami
- Department of Chemistry, Graduate School of ScienceKyoto UniversityKyotoJapan
| | - Yusuke Nakasone
- Department of Chemistry, Graduate School of ScienceKyoto UniversityKyotoJapan
| | - Masahide Terazima
- Department of Chemistry, Graduate School of ScienceKyoto UniversityKyotoJapan
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6
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Chen Z, Kang XW, Zhou Y, Zhou Z, Tang S, Zou S, Wang K, Huang J, Ding B, Zhong D. Dissecting the Ultrafast Stepwise Bidirectional Proton Relay in a Blue-Light Photoreceptor. J Am Chem Soc 2023; 145:3394-3400. [PMID: 36722850 DOI: 10.1021/jacs.2c10206] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Proton relays through H-bond networks are essential in realizing the functionality of protein machines such as in photosynthesis and photoreceptors. It has been challenging to dissect the rates and energetics of individual proton-transfer steps during the proton relay. Here, we have designed a proton rocking blue light using a flavin (BLUF) domain with the flavin mononucleotide (FMN)-glutamic acid (E)-tryptophan (W) triad and have resolved the four individual proton-transfer steps kinetically using ultrafast spectroscopy. We have found that after the photo-induced charge separation forming FMN·-/E-COOH/WH·+, the proton first rapidly jumps from the bridging E-COOH to FMN- (τfPT2 = 3.8 ps; KIE = 1.0), followed by a second proton transfer from WH·+ to E-COO- (τfPT1 = 336 ps; KIE = 2.6) which immediately rocks back to W· (τrPT1 = 85 ps; KIE = 6.7), followed by a proton return from FMNH· to E-COO- (τrPT2 = 34 ps; KIE = 3.3) with the final charge recombination between FMN·- and WH·+ to close the reaction cycle. Our results revisited the Grotthuss mechanism on the ultrafast timescale using the BLUF domain as a paradigm protein.
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Affiliation(s)
- Zijing Chen
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Xiu-Wen Kang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Yalin Zhou
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Zhongneng Zhou
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Siwei Tang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Shuhua Zou
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Kailin Wang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Jiulong Huang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Bei Ding
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China
| | - Dongping Zhong
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai200240, China.,Department of Physics, Department of Chemistry and Biochemistry, and Programs of Biophysics, Chemical Physics, and Biochemistry, The Ohio State University, Columbus, Ohio43210, United States.,School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai200240, China
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7
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Hontani Y, Mehlhorn J, Domratcheva T, Beck S, Kloz M, Hegemann P, Mathes T, Kennis JTM. Spectroscopic and Computational Observation of Glutamine Tautomerization in the Blue Light Sensing Using Flavin Domain Photoreaction. J Am Chem Soc 2023; 145:1040-1052. [PMID: 36607126 PMCID: PMC9853863 DOI: 10.1021/jacs.2c10621] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Blue light sensing using flavin (BLUF) domains constitute a family of flavin-binding photoreceptors of bacteria and eukaryotic algae. BLUF photoactivation proceeds via a light-driven hydrogen-bond switch among flavin adenine dinucleotide (FAD) and glutamine and tyrosine side chains, whereby FAD undergoes electron and proton transfer with tyrosine and is subsequently re-oxidized by a hydrogen back-shuttle in picoseconds, constituting an important model system to understand proton-coupled electron transfer in biology. The specific structure of the hydrogen-bond patterns and the prevalence of glutamine tautomeric states in dark-adapted (DA) and light-activated (LA) states have remained controversial. Here, we present a combined femtosecond stimulated Raman spectroscopy (FSRS), computational chemistry, and site-selective isotope labeling Fourier-transform infrared spectroscopy (FTIR) study of the Slr1694 BLUF domain. FSRS showed distinct vibrational bands from the FADS1 singlet excited state. We observed small but significant shifts in the excited-state vibrational frequency patterns of the DA and LA states, indicating that these frequencies constitute a sensitive probe for the hydrogen-bond arrangement around FAD. Excited-state model calculations utilizing four different realizations of hydrogen bond patterns and glutamine tautomeric states were consistent with a BLUF reaction model that involved glutamine tautomerization to imidic acid, accompanied by a rotation of its side chain. A combined FTIR and double-isotope labeling study, with 13C labeling of FAD and 15N labeling of glutamine, identified the glutamine imidic acid C═N stretch vibration in the LA state and the Gln C═O in the DA state. Hence, our study provides support for glutamine tautomerization and side-chain rotation in the BLUF photoreaction.
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Affiliation(s)
- Yusaku Hontani
- Department
of Physics and Astronomy, Vrije Universiteit
Amsterdam, 1081 HV Amsterdam, De Boelelaan, The Netherlands
| | - Jennifer Mehlhorn
- Institut
für Biologie, Experimentelle Biophysik, Humboldt Universität zu Berlin, Invalidenstrasse 42, D-10115 Berlin, Germany
| | - Tatiana Domratcheva
- Department
of Biomolecular Mechanisms, Max Planck Institute
for Medical Research, 69120 Heidelberg, Germany,Department
of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Sebastian Beck
- Department
of Chemistry, Humboldt-Universität
zu Berlin, Brook-Taylor-Str.
2, 12489 Berlin, Germany
| | - Miroslav Kloz
- Department
of Physics and Astronomy, Vrije Universiteit
Amsterdam, 1081 HV Amsterdam, De Boelelaan, The Netherlands,Institute
of Physics, ELI-Beamlines, Na Slovance 2, 182
21 Praha 8, Czech Republic
| | - Peter Hegemann
- Institut
für Biologie, Experimentelle Biophysik, Humboldt Universität zu Berlin, Invalidenstrasse 42, D-10115 Berlin, Germany
| | - Tilo Mathes
- Department
of Physics and Astronomy, Vrije Universiteit
Amsterdam, 1081 HV Amsterdam, De Boelelaan, The Netherlands,Institut
für Biologie, Experimentelle Biophysik, Humboldt Universität zu Berlin, Invalidenstrasse 42, D-10115 Berlin, Germany
| | - John T. M. Kennis
- Department
of Physics and Astronomy, Vrije Universiteit
Amsterdam, 1081 HV Amsterdam, De Boelelaan, The Netherlands,
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8
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Kulakova AM, Khrenova MG, Nemukhin AV. Non-Equivalence of Monomers in the Dimeric Structure of a Bacterial Photoactivated Adenylyl Cyclase. Biophysics (Nagoya-shi) 2022. [DOI: 10.1134/s0006350922060112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023] Open
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9
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Nakasone Y, Terazima M. Time-resolved diffusion reveals photoreactions of BLUF proteins with similar functional domains. Photochem Photobiol Sci 2022; 21:493-507. [PMID: 35391638 DOI: 10.1007/s43630-022-00214-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 03/21/2022] [Indexed: 11/30/2022]
Abstract
BLUF (blue light sensor using flavin) proteins are the blue light receptors that consist of flavin-binding BLUF domains and functional domains. Upon blue light excitation, the hydrogen bond network around the flavin chromophore changes, and the absorption spectrum in the visible region shifts to red. Light signal received in the BLUF domain is intramolecularly or intermolecularly transmitted to the functional region. In this review, the reactions of three BLUF proteins with similar EAL functional groups within the protein (BlrP1, and YcgF), or with a separated target protein (PapB) are described using time-resolved diffusion technique. The diffusion coefficients (D) of the BLUF domains did not significantly change upon photoexcitation, whereas those of the full-length proteins BlrP1 and YcgF and the PapB-PapA system significantly decreased. The changes in D should be due to diffusion-sensitive conformational changes (DSCC) that alter the friction of diffusion. The time constants of the major D changes of BlrP1 and PapB-PapA were similar (~ 20 ms), although the magnitude of the friction change depended on the proteins. Similarities and differences among the reactions of these proteins were clarified from the viewpoint of DSCC.
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Affiliation(s)
- Yusuke Nakasone
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan
| | - Masahide Terazima
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, 606-8502, Japan.
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10
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Tokonami S, Onose M, Nakasone Y, Terazima M. Slow Conformational Changes of Blue Light Sensor BLUF Proteins in Milliseconds. J Am Chem Soc 2022; 144:4080-4090. [PMID: 35196858 DOI: 10.1021/jacs.1c13121] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Blue light sensor using flavin (BLUF) proteins consist of flavin-binding BLUF domains and functional domains. Upon blue light excitation, the hydrogen bond network around the flavin chromophore changes, and the absorption spectrum in the visible region exhibits a red shift. Ultimately, the light information received in the BLUF domain is transmitted to the functional region. It has been believed that this red shift is complete within nanoseconds. In this study, slow reaction kinetics were discovered in milliseconds (τ1- and τ2-phase) for all the BLUF proteins examined (AppA, OaPAC, BlrP1, YcgF, PapB, SyPixD, and TePixD). Despite extensive reports on BLUF, this is the first clear observation of the BLUF protein absorption change with the duration in the millisecond time region. From the measurements of some domain-deleted mutants of OaPAC and two chimeric mutants of PixD proteins, it was found that the slower dynamics (τ2-phase) are strongly affected by the size and nature of the C-terminal region adjacent to the BLUF domain. Hence, this millisecond reaction is a significant indicator of conformational changes in the C-terminal region, which is essential for the biological functions. On the other hand, the τ1-phase commonly exists in all BLUF proteins, including any mutants. The origin of the slow dynamics was studied using site-specific mutants. These results clearly show the importance of Trp in the BLUF domain. Based on this, a reaction scheme for the BLUF reaction is proposed.
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Affiliation(s)
- Shunrou Tokonami
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Morihiko Onose
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Yusuke Nakasone
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Masahide Terazima
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
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11
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Ravensbergen J, Pillai S, Méndez-Hernández DD, Frese RN, van Grondelle R, Gust D, Moore TA, Moore AL, Kennis JTM. Dual Singlet Excited-State Quenching Mechanisms in an Artificial Caroteno-Phthalocyanine Light Harvesting Antenna. ACS PHYSICAL CHEMISTRY AU 2022; 2:59-67. [PMID: 35098245 PMCID: PMC8796278 DOI: 10.1021/acsphyschemau.1c00008] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 09/29/2021] [Accepted: 09/29/2021] [Indexed: 11/29/2022]
Abstract
![]()
Under excess illumination,
photosystem II of plants dissipates
excess energy through the quenching of chlorophyll fluorescence in
the light harvesting antenna. Various models involving chlorophyll
quenching by carotenoids have been proposed, including (i) direct
energy transfer from chlorophyll to the low-lying optically forbidden
carotenoid S1 state, (ii) formation of a collective quenched
chlorophyll–carotenoid S1 excitonic state, (iii)
chlorophyll–carotenoid charge separation and recombination,
and (iv) chlorophyll–chlorophyll charge separation and recombination.
In previous work, the first three processes were mimicked in model
systems: in a Zn-phthalocyanine–carotenoid dyad with an amide
linker, direct energy transfer was observed by femtosecond transient
absorption spectroscopy, whereas in a Zn-phthalocyanine–carotenoid
dyad with an amine linker excitonic quenching was demonstrated. Here,
we present a transient absorption spectroscopic study on a Zn-phthalocyanine–carotenoid
dyad with a phenylene linker. We observe that two quenching phases
of the phthalocyanine excited state exist at 77 and 213 ps in addition
to an unquenched phase at 2.7 ns. Within our instrument response of
∼100 fs, carotenoid S1 features rise which point
at an excitonic quenching mechanism. Strikingly, we observe an additional
rise of carotenoid S1 features at 3.6 ps, which shows that
a direct energy transfer mechanism in an inverted kinetics regime
is also in effect. We assign the 77 ps decay component to excitonic
quenching and the 3.6 ps/213 ps rise and decay components to direct
energy transfer. Our results indicate that dual quenching mechanisms
may be active in the same molecular system, in addition to an unquenched
fraction. Computational chemistry results indicate the presence of
multiple conformers where one of the dihedral angles of the phenylene
linker assumes distinct values. We propose that the parallel quenching
pathways and the unquenched fraction result from such conformational
subpopulations. Our results suggest that it is possible to switch
between different regimes of quenching and nonquenching through a
conformational change on the same molecule, offering insights into
potential mechanisms used in biological photosynthesis to adapt to
light intensity changes on fast time scales.
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Affiliation(s)
- Janneke Ravensbergen
- Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Smitha Pillai
- School of Molecular Sciences and Center for Bioenergy and Photosynthesis, Arizona State University, Tempe, Arizona 85287-1605, United States
| | | | - Raoul N. Frese
- Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Rienk van Grondelle
- Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Devens Gust
- School of Molecular Sciences and Center for Bioenergy and Photosynthesis, Arizona State University, Tempe, Arizona 85287-1605, United States
| | - Thomas A. Moore
- School of Molecular Sciences and Center for Bioenergy and Photosynthesis, Arizona State University, Tempe, Arizona 85287-1605, United States
| | - Ana L. Moore
- School of Molecular Sciences and Center for Bioenergy and Photosynthesis, Arizona State University, Tempe, Arizona 85287-1605, United States
| | - John T. M. Kennis
- Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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12
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Kang X, Chen Z, Zhou Z, Zhou Y, Tang S, Zhang Y, Zhang T, Ding B, Zhong D. Direct Observation of Ultrafast Proton Rocking in the BLUF Domain. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202114423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Xiu‐Wen Kang
- Center for Ultrafast Science and Technology School of Chemistry and Chemical Engineering Shanghai Jiao Tong University Shanghai 200240 China
| | - Zijing Chen
- Center for Ultrafast Science and Technology School of Chemistry and Chemical Engineering Shanghai Jiao Tong University Shanghai 200240 China
| | - Zhongneng Zhou
- Center for Ultrafast Science and Technology School of Chemistry and Chemical Engineering Shanghai Jiao Tong University Shanghai 200240 China
| | - Yalin Zhou
- Center for Ultrafast Science and Technology School of Chemistry and Chemical Engineering Shanghai Jiao Tong University Shanghai 200240 China
| | - Siwei Tang
- Center for Ultrafast Science and Technology School of Chemistry and Chemical Engineering Shanghai Jiao Tong University Shanghai 200240 China
| | - Yifei Zhang
- Center for Ultrafast Science and Technology School of Chemistry and Chemical Engineering Shanghai Jiao Tong University Shanghai 200240 China
| | - Tianyi Zhang
- Center for Ultrafast Science and Technology School of Chemistry and Chemical Engineering Shanghai Jiao Tong University Shanghai 200240 China
| | - Bei Ding
- Center for Ultrafast Science and Technology School of Chemistry and Chemical Engineering Shanghai Jiao Tong University Shanghai 200240 China
| | - Dongping Zhong
- Center for Ultrafast Science and Technology School of Chemistry and Chemical Engineering Shanghai Jiao Tong University Shanghai 200240 China
- Department of Physics Department of Chemistry and Biochemistry and Programs of Biophysics Chemical Physics, and Biochemistry The Ohio State University Columbus OH 43210 USA
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13
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Ding B, Kang XW, Chen Z, Zhou Z, Zhou Y, Tang S, Zhang Y, Zhang T, Zhong D. Direct Observation of Ultrafast Proton Rocking in the BLUF Domain. Angew Chem Int Ed Engl 2021; 61:e202114423. [PMID: 34927328 DOI: 10.1002/anie.202114423] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Indexed: 11/10/2022]
Abstract
We present direct observation of ultrafast proton rocking in the central motif of a BLUF domain protein scaffold. The mutant design has taken considerations of modulating the proton-coupled electron transfer (PCET) driving forces by replacing Tyr in the original motif with Trp, as well as of removing the interference of a competing electron transfer pathway. Using femtosecond pump-probe spectroscopy and detailed kinetics analysis, we resolved an electron-transfer-coupled Grotthuss-type forward and reversed proton rocking along the FMN-Gln-Trp proton relay chain. The rates of forward and reversed proton transfer are determined to be very close, namely 51 ps vs 52 ps. The kinetic isotope effect (KIE) constants associated with the forward and reversed proton transfer are 3.9 and 5.3, respectively. The observation of ultrafast proton rocking is not only a crucial step towards revealing the nature of proton relay in BLUF domain, but also provides a new paradigm of proton transfer in proteins for theoretical investigations.
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Affiliation(s)
- Bei Ding
- Shanghai Jiao Tong University, School of Chemistry and Chemical Engineering, 800 Dongchuan Road, 200240, Shanghai, CHINA
| | - Xiu-Wen Kang
- Shanghai Jiao Tong University, School of Chemistry and Chemical Engineering, CHINA
| | - Zijing Chen
- Shanghai Jiao Tong University, School of Chemistry and Chemical Engineering, CHINA
| | - Zhongneng Zhou
- Shanghai Jiao Tong University, School of Chemistry and Chemical Engineering, CHINA
| | - Yalin Zhou
- Shanghai Jiao Tong University, School of Chemistry and Chemical Engineering, CHINA
| | - Siwei Tang
- Shanghai Jiao Tong University, School of Chemistry and Chemical Engineering, CHINA
| | - Yifei Zhang
- Shanghai Jiao Tong University, School of Chemistry and Chemical Engineering, CHINA
| | - Tianyi Zhang
- Shanghai Jiao Tong University, School of Chemistry and Chemical Engineering, CHINA
| | - Dongping Zhong
- The Ohio State University, Department of Chemical and Biomolecular Engineering, CHINA
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14
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Kulakova AM, Khrenova MG, Nemukhin AV. Structure and dynamics of photoactivatable adenylyl cyclase. Russ Chem Bull 2019. [DOI: 10.1007/s11172-019-2657-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Hall CR, Tolentino Collado J, Iuliano JN, Gil AA, Adamczyk K, Lukacs A, Greetham GM, Sazanovich I, Tonge PJ, Meech SR. Site-Specific Protein Dynamics Probed by Ultrafast Infrared Spectroscopy of a Noncanonical Amino Acid. J Phys Chem B 2019; 123:9592-9597. [DOI: 10.1021/acs.jpcb.9b09425] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - James N. Iuliano
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Agnieszka A. Gil
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Katrin Adamczyk
- School of Chemistry, University of East Anglia, Norwich NR4 7TJ, U.K
| | - Andras Lukacs
- Department of Biophysics, Medical School, University of Pecs, Szigeti ut 12, 7624 Pecs, Hungary
| | - Gregory M. Greetham
- Central Laser Facility, Research Complex at Harwell, Harwell Science and Innovation Campus, Didcot, Oxon OX11 0QX, U.K
| | - Igor Sazanovich
- Central Laser Facility, Research Complex at Harwell, Harwell Science and Innovation Campus, Didcot, Oxon OX11 0QX, U.K
| | - Peter J. Tonge
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Stephen R. Meech
- School of Chemistry, University of East Anglia, Norwich NR4 7TJ, U.K
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16
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Sayfutyarova ER, Hammes-Schiffer S. Constructing Molecular π-Orbital Active Spaces for Multireference Calculations of Conjugated Systems. J Chem Theory Comput 2019; 15:1679-1689. [PMID: 30689378 PMCID: PMC6526033 DOI: 10.1021/acs.jctc.8b01196] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Molecules with conjugated π systems often feature strong electron correlation and therefore require multireference methods for a reliable computational description. A key prerequisite for the successful application of such methods is the choice of a suitable active space. Herein the automated π-orbital space (PiOS) method for selecting active spaces for multireference calculations of conjugated π systems is presented. This approach allows the construction of small but effective active spaces based on Hückel theory. To demonstrate its performance, π → π* excitations for benzene, octatetraene, and free-base porphine are computed. In addition, this technique can be combined with the automated atomic valence active space method to compute excitations in complex systems with multiple conjugated fragments. This combined approach was used to generate two-dimensional potential energy surfaces for multiple electronic states associated with photoinduced electron-coupled double proton transfer in the blue-light-using flavin photoreceptor protein. These types of methods for the automated selection of active space orbitals are important for ensuring consistency and reproducibility of multireference approaches for a wide range of chemical and biological systems.
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Affiliation(s)
- Elvira R. Sayfutyarova
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520
| | - Sharon Hammes-Schiffer
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520
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17
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Sayfutyarova ER, Goings JJ, Hammes-Schiffer S. Electron-Coupled Double Proton Transfer in the Slr1694 BLUF Photoreceptor: A Multireference Electronic Structure Study. J Phys Chem B 2018; 123:439-447. [DOI: 10.1021/acs.jpcb.8b10973] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Elvira R. Sayfutyarova
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Joshua J. Goings
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Sharon Hammes-Schiffer
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
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18
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Lacombat F, Espagne A, Dozova N, Plaza P, Ignatz E, Kiontke S, Essen LO. Delocalized hole transport coupled to sub-ns tryptophanyl deprotonation promotes photoreduction of class II photolyases. Phys Chem Chem Phys 2018; 20:25446-25457. [PMID: 30272080 DOI: 10.1039/c8cp04548h] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Class II photolyases utilize for the photoreduction of their flavin cofactor (FAD) a completely different tryptophan triad than most other photolyases and cryptochromes. To counter sped-up back electron transfer, they evolved an unusually fast deprotonation of the distal tryptophanyl radical cation (WH˙+) that is produced after excitation of the flavin. We studied the primary aspects of oxidized FAD photoreduction by ultrafast transient absorption spectroscopy, using the class II photolyase from Methanosarcina mazei. With a time constant of 9.2 ps, the initial reduction step of the excited flavin by the proximal W381 tryptophan proceeds almost twentyfold slower than in other photolyases carrying oxidized FAD, most likely because of the larger distance between the flavin and the proximal tryptophan. The thus formed W381H˙+ radical is tracked by transient anisotropy measurements to migrate in 29 ps with delocalization over several members of the tryptophan triad. This 29 ps phase also includes the decay of a small fraction of excited flavin, reacting on a slower timescale, and partial recombination of the FAD˙-/WH˙+ radical pair. A final kinetic phase in 230 ps is assigned to the deprotonation of W388H˙+ that occurs in competition with partial charge recombination. Interestingly, we show by comparison with the Y345F mutant that this last phase additionally involves oxidation of the Y345 phenolic group by W388H˙+, producing a small amount of neutral tyrosyl radical (YO˙). The rate of this electron transfer step is about six orders of magnitude faster than the corresponding oxidation of Y345 by the deprotonated W388˙ radical. Unlike conventional photolyases, where the electron hole accumulates on the distal tryptophan before the much slower tryptophanyl deprotonation, our data show that delocalized hole transport is concomitantly concluded by ultrafast deprotonation of W388H˙+.
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Affiliation(s)
- Fabien Lacombat
- PASTEUR, Département de chimie, École normale supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France.
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19
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Goings JJ, Reinhardt CR, Hammes-Schiffer S. Propensity for Proton Relay and Electrostatic Impact of Protein Reorganization in Slr1694 BLUF Photoreceptor. J Am Chem Soc 2018; 140:15241-15251. [DOI: 10.1021/jacs.8b07456] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Joshua J. Goings
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Clorice R. Reinhardt
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
| | - Sharon Hammes-Schiffer
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, United States
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20
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Magerl K, Stambolic I, Dick B. Switching from adduct formation to electron transfer in a light-oxygen-voltage domain containing the reactive cysteine. Phys Chem Chem Phys 2018; 19:10808-10819. [PMID: 28271102 DOI: 10.1039/c6cp08370f] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
LOV (light-, oxygen- or voltage-sensitive) domains act as photosensory units of many prokaryotic and eukaryotic proteins. Upon blue light excitation they undergo a photocycle via the excited triplet state of their flavin chromophore yielding the flavin-cysteinyl adduct. Adduct formation is highly conserved among all LOV domains and constitutes the primary step of LOV domain signaling. But recently, it has been shown that signal propagation can also be triggered by flavin photoreduction to the neutral semiquinone offering new prospects for protein engineering. This, however, requires mutation of the photo-active Cys. Here, we report on LOV1 mutants of C. reinhardtii phototropin in which adduct formation is suppressed although the photo-active Cys is present. Introduction of a Tyr into the LOV core induces a proton coupled electron transfer towards the flavin chromophore. Flavin radical species are formed via either the excited flavin singlet or triplet state depending on the geometry of donor and acceptor. This photoreductive pathway resembles the photoreaction observed in other blue light photoreceptors, e.g. blue-light sensors using flavin adenine dinucleotide (BLUF) domains or cryptochromes. The ability to tune the photoreactivity of the flavin chromophore inside the LOV core has implications for the mechanism of adduct formation in the wild type and may be of use for protein engineering.
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Affiliation(s)
- Kathrin Magerl
- Institute of Physical and Theoretical Chemistry, University of Regensburg, Universitaetsstrasse 31, 93053 Regensburg, Germany.
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21
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Fujisawa T, Masuda S. Light-induced chromophore and protein responses and mechanical signal transduction of BLUF proteins. Biophys Rev 2017; 10:327-337. [PMID: 29235080 PMCID: PMC5899715 DOI: 10.1007/s12551-017-0355-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 11/15/2017] [Indexed: 11/26/2022] Open
Abstract
Photoreceptor proteins have been used to study how protein conformational changes are induced by alterations in their environments and how their signals are transmitted to downstream factors to dictate physiological responses. These proteins are attractive models because their signal transduction aspects and structural changes can be precisely regulated in vivo and in vitro based on light intensity. Among the known photoreceptors, members of the blue light–using flavin (BLUF) protein family have been well characterized with regard to how they control various light-dependent physiological responses in several microorganisms. Herein, we summarize our current understanding of their photoactivation and signal-transduction mechanisms. For signal transduction, we review recent studies concerning how the BLUF protein, PixD, transmits a light-induced signal to its downstream factor, PixE, to modulate phototaxis of the cyanobacterium Synechocystis sp. PCC6803.
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Affiliation(s)
- Tomotsumi Fujisawa
- Department of Chemistry, Graduate School of Science and Engineering, Saga University, Saga, 840-8502 Japan
| | - Shinji Masuda
- Center for Biological Resources & Informatics, Tokyo Institute of Technology, Yokohama, 226-8501 Japan
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22
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Gil AA, Laptenok SP, Iuliano JN, Lukacs A, Verma A, Hall CR, Yoon GE, Brust R, Greetham GM, Towrie M, French JB, Meech SR, Tonge PJ. Photoactivation of the BLUF Protein PixD Probed by the Site-Specific Incorporation of Fluorotyrosine Residues. J Am Chem Soc 2017; 139:14638-14648. [PMID: 28876066 DOI: 10.1021/jacs.7b07849] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The flavin chromophore in blue-light-using FAD (BLUF) photoreceptors is surrounded by a hydrogen bond network that senses and responds to changes in the electronic structure of the flavin on the ultrafast time scale. The hydrogen bond network includes a strictly conserved Tyr residue, and previously we explored the role of this residue, Y21, in the photoactivation mechanism of the BLUF protein AppABLUF by the introduction of fluorotyrosine (F-Tyr) analogues that modulated the pKa and reduction potential of Y21 by 3.5 pH units and 200 mV, respectively. Although little impact on the forward (dark- to light-adapted form) photoreaction was observed, the change in Y21 pKa led to a 4000-fold increase in the rate of dark-state recovery. In the present work we have extended these studies to the BLUF protein PixD, where, in contrast to AppABLUF, modulation in the Tyr (Y8) pKa has a profound impact on the forward photoreaction. In particular, a decrease in Y8 pKa by 2 or more pH units prevents formation of a stable light state, consistent with a photoactivation mechanism that involves proton transfer or proton-coupled electron transfer from Y8 to the electronically excited FAD. Conversely, the effect of pKa on the rate of dark recovery is markedly reduced in PixD. These observations highlight very significant differences between the photocycles of PixD and AppABLUF, despite their sharing highly conserved FAD binding architectures.
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Affiliation(s)
| | - Sergey P Laptenok
- School of Chemistry, University of East Anglia , Norwich Research Park, Norwich NR4 7TJ, U.K
| | | | - Andras Lukacs
- Department of Biophysics, Medical School, University of Pecs , Pecs H-7622, Hungary
| | - Anil Verma
- Central Laser Facility, Harwell Science and Innovation Campus , Didcot, Oxon OX11 0QX, U.K
| | - Christopher R Hall
- School of Chemistry, University of East Anglia , Norwich Research Park, Norwich NR4 7TJ, U.K
| | | | | | - Gregory M Greetham
- Central Laser Facility, Harwell Science and Innovation Campus , Didcot, Oxon OX11 0QX, U.K
| | - Michael Towrie
- Central Laser Facility, Harwell Science and Innovation Campus , Didcot, Oxon OX11 0QX, U.K
| | | | - Stephen R Meech
- School of Chemistry, University of East Anglia , Norwich Research Park, Norwich NR4 7TJ, U.K
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23
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Ledbetter RN, Garcia Costas AM, Lubner CE, Mulder DW, Tokmina-Lukaszewska M, Artz JH, Patterson A, Magnuson TS, Jay ZJ, Duan HD, Miller J, Plunkett MH, Hoben JP, Barney BM, Carlson RP, Miller AF, Bothner B, King PW, Peters JW, Seefeldt LC. The Electron Bifurcating FixABCX Protein Complex from Azotobacter vinelandii: Generation of Low-Potential Reducing Equivalents for Nitrogenase Catalysis. Biochemistry 2017; 56:4177-4190. [PMID: 28704608 DOI: 10.1021/acs.biochem.7b00389] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The biological reduction of dinitrogen (N2) to ammonia (NH3) by nitrogenase is an energetically demanding reaction that requires low-potential electrons and ATP; however, pathways used to deliver the electrons from central metabolism to the reductants of nitrogenase, ferredoxin or flavodoxin, remain unknown for many diazotrophic microbes. The FixABCX protein complex has been proposed to reduce flavodoxin or ferredoxin using NADH as the electron donor in a process known as electron bifurcation. Herein, the FixABCX complex from Azotobacter vinelandii was purified and demonstrated to catalyze an electron bifurcation reaction: oxidation of NADH (Em = -320 mV) coupled to reduction of flavodoxin semiquinone (Em = -460 mV) and reduction of coenzyme Q (Em = 10 mV). Knocking out fix genes rendered Δrnf A. vinelandii cells unable to fix dinitrogen, confirming that the FixABCX system provides another route for delivery of electrons to nitrogenase. Characterization of the purified FixABCX complex revealed the presence of flavin and iron-sulfur cofactors confirmed by native mass spectrometry, electron paramagnetic resonance spectroscopy, and transient absorption spectroscopy. Transient absorption spectroscopy further established the presence of a short-lived flavin semiquinone radical, suggesting that a thermodynamically unstable flavin semiquinone may participate as an intermediate in the transfer of an electron to flavodoxin. A structural model of FixABCX, generated using chemical cross-linking in conjunction with homology modeling, revealed plausible electron transfer pathways to both high- and low-potential acceptors. Overall, this study informs a mechanism for electron bifurcation, offering insight into a unique method for delivery of low-potential electrons required for energy-intensive biochemical conversions.
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Affiliation(s)
- Rhesa N Ledbetter
- Department of Chemistry and Biochemistry, Utah State University , Logan, Utah 84322, United States
| | - Amaya M Garcia Costas
- Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59717, United States
| | - Carolyn E Lubner
- National Renewable Energy Laboratory , Golden, Colorado 80401, United States
| | - David W Mulder
- National Renewable Energy Laboratory , Golden, Colorado 80401, United States
| | - Monika Tokmina-Lukaszewska
- Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59717, United States
| | - Jacob H Artz
- Institute of Biological Chemistry, Washington State University , Pullman, Washington 99163, United States
| | - Angela Patterson
- Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59717, United States
| | - Timothy S Magnuson
- Department of Biological Sciences, Idaho State University , Pocatello, Idaho 83201, United States
| | - Zackary J Jay
- Department of Chemical and Biological Engineering, Center for Biofilm Engineering and Thermal Biology Institute, Montana State University , Bozeman, Montana 59717, United States
| | - H Diessel Duan
- Department of Chemistry, University of Kentucky , Lexington, Kentucky 40506, United States
| | - Jacquelyn Miller
- Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59717, United States
| | - Mary H Plunkett
- Department of Bioproducts and Biosystems Engineering and Biotechnology Institute, University of Minnesota , St. Paul, Minnesota 55108, United States
| | - John P Hoben
- Department of Chemistry, University of Kentucky , Lexington, Kentucky 40506, United States
| | - Brett M Barney
- Department of Bioproducts and Biosystems Engineering and Biotechnology Institute, University of Minnesota , St. Paul, Minnesota 55108, United States
| | - Ross P Carlson
- Department of Chemical and Biological Engineering, Center for Biofilm Engineering and Thermal Biology Institute, Montana State University , Bozeman, Montana 59717, United States
| | - Anne-Frances Miller
- Department of Chemistry, University of Kentucky , Lexington, Kentucky 40506, United States
| | - Brian Bothner
- Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59717, United States
| | - Paul W King
- National Renewable Energy Laboratory , Golden, Colorado 80401, United States
| | - John W Peters
- Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59717, United States.,Institute of Biological Chemistry, Washington State University , Pullman, Washington 99163, United States
| | - Lance C Seefeldt
- Department of Chemistry and Biochemistry, Utah State University , Logan, Utah 84322, United States
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24
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Molecular mechanism of photoactivation of a light-regulated adenylate cyclase. Proc Natl Acad Sci U S A 2017; 114:8562-8567. [PMID: 28739908 DOI: 10.1073/pnas.1704391114] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The photoactivated adenylate cyclase (PAC) from the photosynthetic cyanobacterium Oscillatoria acuminata (OaPAC) detects light through a flavin chromophore within the N-terminal BLUF domain. BLUF domains have been found in a number of different light-activated proteins, but with different relative orientations. The two BLUF domains of OaPAC are found in close contact with each other, forming a coiled coil at their interface. Crystallization does not impede the activity switching of the enzyme, but flash cooling the crystals to cryogenic temperatures prevents the signature spectral changes that occur on photoactivation/deactivation. High-resolution crystallographic analysis of OaPAC in the fully activated state has been achieved by cryocooling the crystals immediately after light exposure. Comparison of the isomorphous light- and dark-state structures shows that the active site undergoes minimal changes, yet enzyme activity may increase up to 50-fold, depending on conditions. The OaPAC models will assist the development of simple, direct means to raise the cyclic AMP levels of living cells by light, and other tools for optogenetics.
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25
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Abatedaga I, Valle L, Golic AE, Müller GL, Cabruja M, Morán Vieyra FE, Jaime PC, Mussi MA, Borsarelli CD. Integration of Temperature and Blue-Light Sensing in Acinetobacter baumannii
Through the BlsA Sensor. Photochem Photobiol 2017; 93:805-814. [DOI: 10.1111/php.12760] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Accepted: 02/17/2017] [Indexed: 01/10/2023]
Affiliation(s)
- Inés Abatedaga
- Instituto de Bionanotecnología del NOA (INBIONATEC); Universidad Nacional de Santiago del Estero (UNSE); CONICET; Santiago del Estero Argentina
| | - Lorena Valle
- Instituto de Bionanotecnología del NOA (INBIONATEC); Universidad Nacional de Santiago del Estero (UNSE); CONICET; Santiago del Estero Argentina
| | - Adrián E. Golic
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET); Universidad Nacional de Rosario (UNR); Rosario Argentina
| | - Gabriela L. Müller
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET); Universidad Nacional de Rosario (UNR); Rosario Argentina
| | - Matías Cabruja
- Instituto de Biología Molecular y Celular de Rosario (IBR-CONICET); Universidad Nacional de Rosario (UNR); Rosario Argentina
| | - Faustino E. Morán Vieyra
- Instituto de Bionanotecnología del NOA (INBIONATEC); Universidad Nacional de Santiago del Estero (UNSE); CONICET; Santiago del Estero Argentina
| | - Paula C. Jaime
- Instituto de Bionanotecnología del NOA (INBIONATEC); Universidad Nacional de Santiago del Estero (UNSE); CONICET; Santiago del Estero Argentina
| | - María Alejandra Mussi
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET); Universidad Nacional de Rosario (UNR); Rosario Argentina
| | - Claudio D. Borsarelli
- Instituto de Bionanotecnología del NOA (INBIONATEC); Universidad Nacional de Santiago del Estero (UNSE); CONICET; Santiago del Estero Argentina
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26
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Khrenova MG, Domratcheva T, Nemukhin AV. Molecular mechanism of the dark-state recovery in BLUF photoreceptors. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.03.035] [Citation(s) in RCA: 7] [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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27
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Park SY, Tame JRH. Seeing the light with BLUF proteins. Biophys Rev 2017; 9:169-176. [PMID: 28510088 DOI: 10.1007/s12551-017-0258-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 03/05/2017] [Indexed: 10/19/2022] Open
Abstract
First described about 15 years ago, BLUF (Blue Light Using Flavin) domains are light-triggered switches that control enzyme activity or gene expression in response to blue light, remaining activated for seconds or even minutes after stimulation. The conserved, ferredoxin-like fold holds a flavin chromophore that captures the light and somehow triggers downstream events. BLUF proteins are found in both prokaryotes and eukaryotes and have a variety of architectures and oligomeric forms, but the BLUF domain itself seems to have a well-preserved structure and mechanism that have been the focus of intense study for a number of years. Crystallographic and NMR structures of BLUF domains have been solved, but the conflicting models have led to considerable debate about the atomic details of photo-activation. Advanced spectroscopic and computational methods have been used to analyse the early events after photon absorption, but these too have led to widely differing conclusions. New structural models are improving our understanding of the details of the mechanism and may lead to novel tailor-made tools for optogenetics.
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Affiliation(s)
- Sam-Yong Park
- Drug Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro, Tsurumi, Yokohama, 230-0045, Japan
| | - Jeremy R H Tame
- Drug Design Laboratory, Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro, Tsurumi, Yokohama, 230-0045, Japan.
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28
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Losi A, Gärtner W. Solving Blue Light Riddles: New Lessons from Flavin-binding LOV Photoreceptors. Photochem Photobiol 2017; 93:141-158. [PMID: 27861974 DOI: 10.1111/php.12674] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Accepted: 10/22/2016] [Indexed: 12/15/2022]
Abstract
Detection of blue light (BL) via flavin-binding photoreceptors (Fl-Blues) has evolved throughout all three domains of life. Although the main BL players, that is light, oxygen and voltage (LOV), blue light sensing using flavins (BLUF) and Cry (cryptochrome) proteins, have been characterized in great detail with respect to structure and function, still several unresolved issues at different levels of complexity remain and novel unexpected findings were reported. Here, we review the most prevailing riddles of LOV-based photoreceptors, for example: the relevance of water and/or small metabolites for the dynamics of the photocycle; molecular details of light-to-signal transduction events; the interplay of BL sensing by LOV domains with other environmental stimuli, such as BL plus oxygen-mediating photodamage and its impact on microbial lifestyles; the importance of the cell or chromophore redox state in determining the fate of BL-driven reactions; the evolutionary pathways of LOV-based BL sensing and associated functions through the diverse phyla. We will discuss major novelties emerged during the last few years on these intriguing aspects of LOV proteins by presenting paradigmatic examples from prokaryotic photosensors that exhibit the largest complexity and richness in associated functions.
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Affiliation(s)
- Aba Losi
- Department of Physics and Earth Sciences, University of Parma, Parma, Italy
| | - Wolfgang Gärtner
- Max-Planck-Institute for Chemical Energy Conversion, Mülheim, Germany
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29
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Hontani Y, Shcherbakova DM, Baloban M, Zhu J, Verkhusha VV, Kennis JTM. Bright blue-shifted fluorescent proteins with Cys in the GAF domain engineered from bacterial phytochromes: fluorescence mechanisms and excited-state dynamics. Sci Rep 2016; 6:37362. [PMID: 27857208 PMCID: PMC5114657 DOI: 10.1038/srep37362] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 10/25/2016] [Indexed: 11/21/2022] Open
Abstract
Near-infrared fluorescent proteins (NIR FPs) engineered from bacterial phytochromes (BphPs) are of great interest for in vivo imaging. They utilize biliverdin (BV) as a chromophore, which is a heme degradation product, and therefore they are straightforward to use in mammalian tissues. Here, we report on fluorescence properties of NIR FPs with key alterations in their BV binding sites. BphP1-FP, iRFP670 and iRFP682 have Cys residues in both PAS and GAF domains, rather than in the PAS domain alone as in wild-type BphPs. We found that NIR FP variants with Cys in the GAF or with Cys in both PAS and GAF show blue-shifted emission with long fluorescence lifetimes. In contrast, mutants with Cys in the PAS only or no Cys residues at all exhibit red-shifted emission with shorter lifetimes. Combining these results with previous biochemical and BphP1-FP structural data, we conclude that BV adducts bound to Cys in the GAF are the origin of bright blue-shifted fluorescence. We propose that the long fluorescence lifetime follows from (i) a sterically more constrained thioether linkage, leaving less mobility for ring A than in canonical BphPs, and (ii) that π-electron conjugation does not extend on ring A, making excited-state deactivation less sensitive to ring A mobility.
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Affiliation(s)
- Yusaku Hontani
- Department of Physics and Astronomy, VU University Amsterdam, Amsterdam 1081 HV, The Netherlands
| | - Daria M Shcherbakova
- Department of Anatomy and Structural Biology and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Mikhail Baloban
- Department of Anatomy and Structural Biology and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | - Jingyi Zhu
- Department of Physics and Astronomy, VU University Amsterdam, Amsterdam 1081 HV, The Netherlands
| | - Vladislav V Verkhusha
- Department of Anatomy and Structural Biology and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, New York 10461, USA.,Department of Biochemistry and Developmental Biology, Faculty of Medicine, University of Helsinki, Helsinki 00290, Finland
| | - John T M Kennis
- Department of Physics and Astronomy, VU University Amsterdam, Amsterdam 1081 HV, The Netherlands
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30
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Nakajima M, Abe K, Ferri S, Sode K. Development of a light-regulated cell-recovery system for non-photosynthetic bacteria. Microb Cell Fact 2016; 15:31. [PMID: 26875863 PMCID: PMC4753666 DOI: 10.1186/s12934-016-0426-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Accepted: 01/19/2016] [Indexed: 12/02/2022] Open
Abstract
Background Recent advances in the understanding of photosensing in biological systems have enabled the use of photoreceptors as novel genetic tools. Exploiting various photoreceptors that cyanobacteria possess, a green light-inducible gene expression system was previously developed for the regulation of gene expression in cyanobacteria.
However, the applications of cyanobacterial photoreceptors are not limited to these bacteria but are also available for non-photosynthetic microorganisms by the coexpression of a cyanobacterial chromophore with a cyanobacteria-derived photosensing system. An Escherichia coli-derived self-aggregation system based on Antigen 43 (Ag43) has been shown to induce cell self-aggregation of various bacteria by exogenous introduction of the Ag43 gene. Results An E. coli transformant harboring a plasmid encoding the Ag43 structural gene under a green light-regulated gene expression system derived from the cyanobacterium Synechocystis sp. PCC6803 was constructed. Ag43 was inserted downstream of the cpcG2 promoter PcpcG2, and its expression was regulated by green light induction, which was achieved by the functional expression of cyanobacterial CcaS/CcaR by coexpressing its chromophore synthesis gene cassette in E. coli. E. coli transformants harboring this designed system self-aggregated under green light exposure and precipitated, whereas transformants lacking the green light induction system did not. The green light induction system effectively functioned before the cell culture entered the stationary growth phase, and approximately 80 % of the cell culture was recovered by simple decantation. Conclusion This study demonstrated the construction of a cell recovery system for non-photosynthetic microorganisms induced by exposure of cells to green light. The system was regulated by a two-component regulatory system from cyanobacteria, and cell precipitation was mediated by an autotransporter protein, Ag43. Although further strict control and an increase of cell recovery efficiency are necessary, the system represents a novel tool for future bioprocessing with reduced energy and labor required for cell recovery.
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Affiliation(s)
- Mitsuharu Nakajima
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture & Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan. .,Japan Science and Technology Agency, CREST, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan.
| | - Koichi Abe
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture & Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan. .,Japan Science and Technology Agency, CREST, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan.
| | - Stefano Ferri
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture & Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan. .,Japan Science and Technology Agency, CREST, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan. .,Department of Applied Chemistry and Biochemical Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, Shizuoka, 432-8561, Japan.
| | - Koji Sode
- Department of Biotechnology and Life Science, Graduate School of Engineering, Tokyo University of Agriculture & Technology, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan. .,Japan Science and Technology Agency, CREST, 2-24-16 Naka-cho, Koganei, Tokyo, 184-8588, Japan.
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31
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Mehlhorn J, Lindtner T, Richter F, Glass K, Steinocher H, Beck S, Hegemann P, Kennis JTM, Mathes T. Light-Induced Rearrangement of the β5 Strand in the BLUF Photoreceptor SyPixD (Slr1694). J Phys Chem Lett 2015; 6:4749-4753. [PMID: 26631358 DOI: 10.1021/acs.jpclett.5b02245] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The structural changes that facilitate signal transduction in blue light sensors using FAD (BLUF) photoreceptors and confer the stability of the rearranged hydrogen bond network between flavin and protein in the signaling state are still poorly understood. Here, we investigate a semiconserved Trp residue in SyPixD (Slr1694) by isotope-edited vibrational spectroscopy and site-directed mutagenesis. In the signaling state, a β-sheet structure involving the backbone of W91 is formed without apparent change of environment of the W91 indole side chain. Mutation of W91, however, significantly influences the stability of the light-adapted state, suggesting that backbone rigidity rather than discrete side-chain conformations govern the stability of the light-adapted state. On the basis of computational and crystallographic models, we interpret these changes as a +1 register shift of the β2/β5 interaction with an unaffected indole side-chain conformation, rather than a +2 register shift accompanied by an indole side-chain flip that was previously proposed on the basis of X-ray structures.
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Affiliation(s)
- Jennifer Mehlhorn
- Department of Biology, Experimental Biophysics, Humboldt-Universität zu Berlin , Invalidenstraße 42, 10115 Berlin, Germany
| | - Tom Lindtner
- Department of Biology, Experimental Biophysics, Humboldt-Universität zu Berlin , Invalidenstraße 42, 10115 Berlin, Germany
| | - Florian Richter
- Department of Biology, Experimental Biophysics, Humboldt-Universität zu Berlin , Invalidenstraße 42, 10115 Berlin, Germany
| | - Kathrin Glass
- Department of Biology, Experimental Biophysics, Humboldt-Universität zu Berlin , Invalidenstraße 42, 10115 Berlin, Germany
| | - Helena Steinocher
- Department of Biology, Experimental Biophysics, Humboldt-Universität zu Berlin , Invalidenstraße 42, 10115 Berlin, Germany
| | - Sebastian Beck
- Department of Chemistry, Humboldt-Universität zu Berlin , Brook-Taylor-Str. 2, 12489 Berlin, Germany
| | - Peter Hegemann
- Department of Biology, Experimental Biophysics, Humboldt-Universität zu Berlin , Invalidenstraße 42, 10115 Berlin, Germany
| | - John T M Kennis
- Department of Physics and Astronomy, Biophysics Section, Faculty of Sciences, Vrije Universiteit , De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | - Tilo Mathes
- Department of Biology, Experimental Biophysics, Humboldt-Universität zu Berlin , Invalidenstraße 42, 10115 Berlin, Germany
- Department of Physics and Astronomy, Biophysics Section, Faculty of Sciences, Vrije Universiteit , De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
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32
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Mathes T, Götze JP. A proposal for a dipole-generated BLUF domain mechanism. Front Mol Biosci 2015; 2:62. [PMID: 26579529 PMCID: PMC4630285 DOI: 10.3389/fmolb.2015.00062] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 10/12/2015] [Indexed: 11/25/2022] Open
Abstract
The resting and signaling structures of the blue-light sensing using flavin (BLUF) photoreceptor domains are still controversially debated due to differences in the molecular models obtained by crystal and NMR structures. Photocycles for the given preferred structural framework have been established, but a unifying picture combining experiment and theory remains elusive. We summarize present work on the AppA BLUF domain from both experiment and theory. We focus on IR and UV/vis spectra, and to what extent theory was able to reproduce experimental data and predict the structural changes upon formation of the signaling state. We find that the experimental observables can be theoretically reproduced employing any structural model, as long as the orientation of the signaling essential Gln63 and its tautomer state are a choice of the modeler. We also observe that few approaches are comparative, e.g., by considering all structures in the same context. Based on recent experimental findings and a few basic calculations, we suggest the possibility for a BLUF activation mechanism that only relies on electron transfer and its effect on the local electrostatics, not requiring an associated proton transfer. In this regard, we investigate the impact of dispersion correction on the interaction energies arising from weakly bound amino acids.
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Affiliation(s)
- Tilo Mathes
- Biophysics Group, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, Netherlands ; Institut für Biologie/Experimentelle Biophysik, Humboldt Universität zu Berlin Berlin, Germany
| | - Jan P Götze
- School of Chemistry, University of St Andrews St Andrews, UK
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33
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Richter F, Scheib US, Mehlhorn J, Schubert R, Wietek J, Gernetzki O, Hegemann P, Mathes T, Möglich A. Upgrading a microplate reader for photobiology and all-optical experiments. Photochem Photobiol Sci 2015; 14:270-9. [PMID: 25373866 DOI: 10.1039/c4pp00361f] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Automation can vastly reduce the cost of experimental labor and thus facilitate high experimental throughput, but little off-the-shelf hardware for the automation of illumination experiments is commercially available. Here, we use inexpensive open-source electronics to add programmable illumination capabilities to a multimode microplate reader. We deploy this setup to characterize light-triggered phenomena in three different sensory photoreceptors. First, we study the photoactivation of Arabidopsis thaliana phytochrome B by light of different wavelengths. Second, we investigate the dark-state recovery kinetics of the Synechocystis sp. blue-light sensor Slr1694 at multiple temperatures and imidazole concentrations; while the kinetics of the W91F mutant of Slr1694 are strongly accelerated by imidazole, the wild-type protein is hardly affected. Third, we determine the light response of the Beggiatoa sp. photoactivatable adenylate cyclase bPAC in Chinese hamster ovary cells. bPAC is activated by blue light in dose-dependent manner with a half-maximal intensity of 0.58 mW cm(-2); intracellular cAMP spikes generated upon bPAC activation decay with a half time of about 5 minutes after light switch-off. Taken together, we present a setup which is easily assembled and which thus offers a facile approach to conducting illumination experiments at high throughput, reproducibility and fidelity.
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Affiliation(s)
- Florian Richter
- Humboldt-Universität zu Berlin, Institut für Biologie, Biophysikalische Chemie, Berlin, Germany.
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34
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Fudim R, Mehlhorn J, Berthold T, Weber S, Schleicher E, Kennis JTM, Mathes T. Photoinduced formation of flavin radicals in BLUF domains lacking the central glutamine. FEBS J 2015; 282:3161-74. [DOI: 10.1111/febs.13297] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 04/08/2015] [Accepted: 04/13/2015] [Indexed: 11/29/2022]
Affiliation(s)
- Roman Fudim
- Institut für Biologie/Experimentelle Biophysik; Humboldt Universität zu Berlin; Berlin Germany
| | - Jennifer Mehlhorn
- Institut für Biologie/Experimentelle Biophysik; Humboldt Universität zu Berlin; Berlin Germany
| | - Thomas Berthold
- Institut für Physikalische Chemie; Albert-Ludwigs-Universität Freiburg; Freiburg Germany
| | - Stefan Weber
- Institut für Physikalische Chemie; Albert-Ludwigs-Universität Freiburg; Freiburg Germany
- Freiburg Institute for Advanced Studies (FRIAS); Albert-Ludwigs-Universität Freiburg; Germany
| | - Erik Schleicher
- Institut für Physikalische Chemie; Albert-Ludwigs-Universität Freiburg; Freiburg Germany
- Inorganic Chemistry Laboratory; University of Oxford; UK
| | - John T. M. Kennis
- Biophysics Section; Department of Physics and Astronomy; Faculty of Sciences; VU University; Amsterdam The Netherlands
| | - Tilo Mathes
- Institut für Biologie/Experimentelle Biophysik; Humboldt Universität zu Berlin; Berlin Germany
- Biophysics Section; Department of Physics and Astronomy; Faculty of Sciences; VU University; Amsterdam The Netherlands
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35
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Conrad KS, Manahan CC, Crane BR. Photochemistry of flavoprotein light sensors. Nat Chem Biol 2014; 10:801-9. [PMID: 25229449 DOI: 10.1038/nchembio.1633] [Citation(s) in RCA: 167] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Accepted: 08/18/2014] [Indexed: 12/22/2022]
Abstract
Three major classes of flavin photosensors, light oxygen voltage (LOV) domains, blue light sensor using FAD (BLUF) proteins and cryptochromes (CRYs), regulate diverse biological activities in response to blue light. Recent studies of structure, spectroscopy and chemical mechanism have provided unprecedented insight into how each family operates at the molecular level. In general, the photoexcitation of the flavin cofactor leads to changes in redox and protonation states that ultimately remodel protein conformation and molecular interactions. For LOV domains, issues remain regarding early photochemical events, but common themes in conformational propagation have emerged across a diverse family of proteins. For BLUF proteins, photoinduced electron transfer reactions critical to light conversion are defined, but the subsequent rearrangement of hydrogen bonding networks key for signaling remains highly controversial. For CRYs, the relevant photocycles are actively debated, but mechanistic and functional studies are converging. Despite these challenges, our current understanding has enabled the engineering of flavoprotein photosensors for control of signaling processes within cells.
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Affiliation(s)
- Karen S Conrad
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, USA
| | - Craig C Manahan
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, USA
| | - Brian R Crane
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, USA
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36
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Fujisawa T, Takeuchi S, Masuda S, Tahara T. Signaling-State Formation Mechanism of a BLUF Protein PapB from the Purple Bacterium Rhodopseudomonas palustris Studied by Femtosecond Time-Resolved Absorption Spectroscopy. J Phys Chem B 2014; 118:14761-73. [PMID: 25406769 DOI: 10.1021/jp5076252] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We studied the signaling-state formation of a BLUF (blue light using FAD) protein, PapB, from the purple bacterium Rhodopseudomonas palustris, using femtosecond time-resolved absorption spectroscopy. Upon photoexcitation of the dark state, FADH(•) (neutral flavin semiquinone FADH radical) was observed as the intermediate before the formation of the signaling state. The kinetic analysis based on singular value decomposition showed that FADH(•) mediates the signaling-state formation, showing that PapB is the second example of FADH(•)-mediated formation of the signaling state after Slr1694 (M. Gauden et al. Proc. Natl. Acad. Sci. U.S.A. 2006, 103, 10895-10900). The mechanism of the signaling-state formation is discussed on the basis of the comparison between femtosecond time-resolved absorption spectra of the dark state and those obtained by exciting the signaling state. FADH(•) was observed also with excitation of the signaling state, and surprisingly, the kinetics of FADH(•) was indistinguishable from the case of exciting the dark state. This result suggests that the hydrogen bond environment in the signaling state is realized before the formation of FADH(•) in the photocycle of PapB.
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Affiliation(s)
- Tomotsumi Fujisawa
- Molecular Spectroscopy Laboratory, RIKEN , 2-1 Hirosawa, Wako 351-0198, Japan
| | - Satoshi Takeuchi
- Molecular Spectroscopy Laboratory, RIKEN , 2-1 Hirosawa, Wako 351-0198, Japan.,Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP), RIKEN , 2-1 Hirosawa, Wako 351-0198, Japan
| | - Shinji Masuda
- Center for Biological Resources and Informatics, and Earth-Life Science Institute, Tokyo Institute of Technology , Yokohama 226-8501, Japan
| | - Tahei Tahara
- Molecular Spectroscopy Laboratory, RIKEN , 2-1 Hirosawa, Wako 351-0198, Japan.,Ultrafast Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP), RIKEN , 2-1 Hirosawa, Wako 351-0198, Japan
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37
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Abstract
Knowledge of the dynamical behavior of proteins, and in particular their conformational fluctuations, is essential to understanding the mechanisms underlying their reactions. Here, transient enhancement of the isothermal partial molar compressibility, which is directly related to the conformational fluctuation, during a chemical reaction of a blue light sensor protein from the thermophilic cyanobacterium Thermosynechococcus elongatus BP-1 (TePixD, Tll0078) was investigated in a time-resolved manner. The UV-Vis absorption spectrum of TePixD did not change with the application of high pressure. Conversely, the transient grating signal intensities representing the volume change depended significantly on the pressure. This result implies that the compressibility changes during the reaction. From the pressure dependence of the amplitude, the compressibility change of two short-lived intermediate (I1 and I2) states were determined to be +(5.6 ± 0.6) × 10(-2) cm(3) ⋅ mol(-1) ⋅ MPa(-1) for I1 and +(6.6 ± 0.7) × 10(-2) cm(3) ⋅ mol(-1) ⋅ MPa(-1) for I2. This result showed that the structural fluctuation of intermediates was enhanced during the reaction. To clarify the relationship between the fluctuation and the reaction, the compressibility of multiply excited TePixD was investigated. The isothermal compressibility of I1 and I2 intermediates of TePixD showed a monotonic decrease with increasing excitation laser power, and this tendency correlated with the reactivity of the protein. This result indicates that the TePixD decamer cannot react when its structural fluctuation is small. We concluded that the enhanced compressibility is an important factor for triggering the reaction of TePixD. To our knowledge, this is the first report showing enhanced fluctuations of intermediate species during a protein reaction, supporting the importance of fluctuations.
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38
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Collette F, Renger T, Schmidt am Busch M. Revealing the functional states in the active site of BLUF photoreceptors from electrochromic shift calculations. J Phys Chem B 2014; 118:11109-19. [PMID: 25153778 PMCID: PMC4174740 DOI: 10.1021/jp506400y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 08/22/2014] [Indexed: 11/28/2022]
Abstract
Photoexcitation with blue light of the flavin chromophore in BLUF photoreceptors induces a switch into a metastable signaling state that is characterized by a red-shifted absorption maximum. The red shift is due to a rearrangement in the hydrogen bond pattern around Gln63 located in the immediate proximity of the isoalloxazine ring system of the chromophore. There is a long-lasting controversy between two structural models, named Q63A and Q63J in the literature, on the local conformation of the residues Gln63 and Tyr21 in the dark state of the photoreceptor. As regards the mechanistic details of the light-activation mechanism, rotation of Gln63 is opposed by tautomerism in the Q63A and Q63J models, respectively. We provide a structure-based simulation of electrochromic shifts of the flavin chromophore in the wild type and in various site-directed mutants. The excellent overall agreement between experimental and computed data allows us to evaluate the two structural models. Compelling evidence is obtained that the Q63A model is incorrect, whereas the Q63J is fully consistent with the present computations. Finally, we confirm independently that a keto-enol tautomerization of the glutamine at position 63, which was proposed as molecular mechanism for the transition between the dark and the light-adapted state, explains the measured 10 to 15 nm red shift in flavin absorption between these two states of the protein. We believe that the accurateness of our results provides evidence that the BLUF photoreceptors absorption is fine-tuned through electrostatic interactions between the chromophore and the protein matrix, and finally that the simplicity of our theoretical model is advantageous as regards easy reproducibility and further extensions.
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Affiliation(s)
- Florimond Collette
- Institut für Theoretische
Physik, Johannes Kepler Universität
Linz, Altenberger Strasse
69, 4040 Linz, Austria
| | - Thomas Renger
- Institut für Theoretische
Physik, Johannes Kepler Universität
Linz, Altenberger Strasse
69, 4040 Linz, Austria
| | - Marcel Schmidt am Busch
- Institut für Theoretische
Physik, Johannes Kepler Universität
Linz, Altenberger Strasse
69, 4040 Linz, Austria
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39
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Stierl M, Penzkofer A, Kennis JTM, Hegemann P, Mathes T. Key Residues for the Light Regulation of the Blue Light-Activated Adenylyl Cyclase from Beggiatoa sp. Biochemistry 2014; 53:5121-30. [DOI: 10.1021/bi500479v] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Manuela Stierl
- Institut
für Biologie/Experimentelle Biophysik, Humboldt Universität zu Berlin, Invalidenstrasse 42, D-10115 Berlin, Germany
| | - Alfons Penzkofer
- Fakultät
für Physik, Universität Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany
| | - John T. M. Kennis
- Department
of Exact Sciences/Biophysics, Vrije Universiteit, De Boelelaan 1081A, 1081 HV Amsterdam, The Netherlands
| | - Peter Hegemann
- Institut
für Biologie/Experimentelle Biophysik, Humboldt Universität zu Berlin, Invalidenstrasse 42, D-10115 Berlin, Germany
| | - Tilo Mathes
- Institut
für Biologie/Experimentelle Biophysik, Humboldt Universität zu Berlin, Invalidenstrasse 42, D-10115 Berlin, Germany
- Department
of Exact Sciences/Biophysics, Vrije Universiteit, De Boelelaan 1081A, 1081 HV Amsterdam, The Netherlands
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40
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Abstract
Most biological photoreceptors are protein/cofactor complexes that induce a physiological reaction upon absorption of a photon. Therefore, these proteins represent signal converters that translate light into biological information. Researchers use this property to stimulate and study various biochemical processes conveniently and non-invasively by the application of light, an approach known as optogenetics. Here, we summarize the recent experimental progress on the family of blue light receptors using FAD (BLUF) receptors. Several BLUF photoreceptors modulate second messenger levels and thus represent highly interesting tools for optogenetic application. In order to activate a coupled effector protein, the flavin-binding pocket of the BLUF domain undergoes a subtle rearrangement of the hydrogen network upon blue light absorption. The hydrogen bond switch is facilitated by the ultrafast light-induced proton-coupled electron transfer (PCET) between a tyrosine and the flavin in less than a nanosecond and remains stable on a long enough timescale for biochemical reactions to take place. The cyclic nature of the photoinduced reaction makes BLUF domains powerful model systems to study protein/cofactor interaction, protein-modulated PCET and novel mechanisms of biological signalling. The ultrafast nature of the photoconversion as well as the subtle structural rearrangement requires sophisticated spectroscopic and molecular biological methods to study and understand this highly intriguing signalling process.
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Affiliation(s)
- John T M Kennis
- Biophysics Group, Department of Physics and Astronomy, Faculty of Sciences , Vrije Universiteit , De Boelelaan 1081, 1081 HV Amsterdam , The Netherlands
| | - Tilo Mathes
- Biophysics Group, Department of Physics and Astronomy, Faculty of Sciences , Vrije Universiteit , De Boelelaan 1081, 1081 HV Amsterdam , The Netherlands
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41
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Migliore A, Polizzi NF, Therien M, Beratan DN. Biochemistry and theory of proton-coupled electron transfer. Chem Rev 2014; 114:3381-465. [PMID: 24684625 PMCID: PMC4317057 DOI: 10.1021/cr4006654] [Citation(s) in RCA: 340] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Indexed: 02/01/2023]
Affiliation(s)
- Agostino Migliore
- Department
of Chemistry, Department of Biochemistry, and Department of Physics, Duke University, Durham, North Carolina 27708, United States
| | - Nicholas F. Polizzi
- Department
of Chemistry, Department of Biochemistry, and Department of Physics, Duke University, Durham, North Carolina 27708, United States
| | - Michael
J. Therien
- Department
of Chemistry, Department of Biochemistry, and Department of Physics, Duke University, Durham, North Carolina 27708, United States
| | - David N. Beratan
- Department
of Chemistry, Department of Biochemistry, and Department of Physics, Duke University, Durham, North Carolina 27708, United States
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42
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Lukacs A, Brust R, Haigney A, Laptenok SP, Addison K, Gil A, Towrie M, Greetham GM, Tonge PJ, Meech SR. BLUF domain function does not require a metastable radical intermediate state. J Am Chem Soc 2014; 136:4605-15. [PMID: 24579721 PMCID: PMC4004230 DOI: 10.1021/ja4121082] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BLUF (blue light using flavin) domain proteins are an important family of blue light-sensing proteins which control a wide variety of functions in cells. The primary light-activated step in the BLUF domain is not yet established. A number of experimental and theoretical studies points to a role for photoinduced electron transfer (PET) between a highly conserved tyrosine and the flavin chromophore to form a radical intermediate state. Here we investigate the role of PET in three different BLUF proteins, using ultrafast broadband transient infrared spectroscopy. We characterize and identify infrared active marker modes for excited and ground state species and use them to record photochemical dynamics in the proteins. We also generate mutants which unambiguously show PET and, through isotope labeling of the protein and the chromophore, are able to assign modes characteristic of both flavin and protein radical states. We find that these radical intermediates are not observed in two of the three BLUF domains studied, casting doubt on the importance of the formation of a population of radical intermediates in the BLUF photocycle. Further, unnatural amino acid mutagenesis is used to replace the conserved tyrosine with fluorotyrosines, thus modifying the driving force for the proposed electron transfer reaction; the rate changes observed are also not consistent with a PET mechanism. Thus, while intermediates of PET reactions can be observed in BLUF proteins they are not correlated with photoactivity, suggesting that radical intermediates are not central to their operation. Alternative nonradical pathways including a keto-enol tautomerization induced by electronic excitation of the flavin ring are considered.
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Affiliation(s)
- Andras Lukacs
- Department of Chemistry, Stony Brook University , Stony Brook, New York 11794-3400, United States
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43
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Raffelberg S, Gutt A, Gärtner W, Mandalari C, Abbruzzetti S, Viappiani C, Losi A. The amino acids surrounding the flavin 7a-methyl group determine the UVA spectral features of a LOV protein. Biol Chem 2014; 394:1517-28. [PMID: 23828427 DOI: 10.1515/hsz-2013-0163] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 07/01/2013] [Indexed: 11/15/2022]
Abstract
Flavin-binding light, oxygen, and voltage (LOV) domains are UVA/blue-light-sensing protein units that form a reversible flavin mononucleotide-cysteine adduct upon light induction. In their dark-adapted state, LOV domains exhibit the typical spectral features of fully oxidized riboflavin derivatives. A survey on the absorption spectra of various LOV domains revealed that the UVA spectral range is the most variable region (whereas the absorption band at 450 nm is virtually unchanged), showing essentially two distinct patterns found in plant phototropin LOV1 and LOV2 domains, respectively. In this work, we have identified a residue directly interacting with the isoalloxazine methyl group at C(7a) as the major UVA spectral tuner. In YtvA from Bacillus subtilis, this amino acid is threonine 30, and its mutation into apolar residues converts the LOV2-like spectrum of native YtvA into a LOV1-like pattern. Mutation T30A also accelerates the photocycle ca. 4-fold. Together with control mutations at different positions, our results experimentally confirm the previously calculated direction of the transition dipole moment for the UVA ππ* state and identify the mechanisms underlying spectral tuning in the LOV domains.
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44
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Kuroi K, Tanaka K, Okajima K, Ikeuchi M, Tokutomi S, Terazima M. Anomalous diffusion of TePixD and identification of the photoreaction product. Photochem Photobiol Sci 2014; 12:1180-6. [PMID: 23535998 DOI: 10.1039/c3pp25434h] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
TePixD is a blue-light sensor protein from the thermophilic cyanobacterium Thermosynechococcus elongatus BP-1 (TePixD Tll0078). Although the photochemistry has been examined, so far the photoproduct remains unknown. We have measured the diffusion coefficient (D) of TePixD in the dark by dynamic light scattering and have discovered a very peculiar diffusion property; the decamer oligomer has a larger D than that of the pentamer. Furthermore, D of the pentamer was found to be very close to that of the TePixD decamer photoreaction product. In order to investigate this reaction further, elution profiles of size-exclusion chromatography were measured under dark and illuminated conditions at low (40 μM) and high (1.1 mM) TePixD concentrations. On the basis of these results, we have concluded that the main photoreaction of the TePixD decamer is the dissociation into the pentamer. The secondary structure change associated with this reaction was found to be minor according to circular dichroism analysis.
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Affiliation(s)
- Kunisato Kuroi
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
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45
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Domratcheva T, Udvarhelyi A, Shahi ARM. Computational spectroscopy, dynamics, and photochemistry of photosensory flavoproteins. Methods Mol Biol 2014; 1146:191-228. [PMID: 24764094 DOI: 10.1007/978-1-4939-0452-5_10] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Extensive interest in photosensory proteins stimulated computational studies of flavins and flavoproteins in the past decade. This review is dedicated to the three central topics of these studies: calculations of flavin UV-visible and IR spectra, simulated dynamics of photoreceptor proteins, and flavin photochemistry. Accordingly, this chapter is divided into three parts; each part describes corresponding computational protocols, summarizes computational results, and discusses the emerging mechanistic picture.
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Affiliation(s)
- Tatiana Domratcheva
- Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, Jahnstraße 29, 69120, Heidelberg, Germany,
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46
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Mathes T, van Stokkum IHM, Kennis JTM. Photoactivation mechanisms of flavin-binding photoreceptors revealed through ultrafast spectroscopy and global analysis methods. Methods Mol Biol 2014; 1146:401-442. [PMID: 24764100 DOI: 10.1007/978-1-4939-0452-5_16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Flavin-binding photoreceptor proteins use the isoalloxazine moiety of flavin cofactors to absorb light in the blue/UV-A wavelength region and subsequently translate it into biological information. The underlying photochemical reactions and protein structural dynamics are delicately tuned by the protein environment and represent fundamental reactions in biology and chemistry. Due to their photo-switchable nature, these proteins can be studied efficiently with laser-flash induced transient absorption and emission spectroscopy with temporal precision down to the femtosecond time domain. Here, we describe the application of both visible and mid-IR ultrafast transient absorption and time-resolved fluorescence methods in combination with sophisticated global analysis procedures to elucidate the photochemistry and signal transduction of BLUF (Blue light receptors using FAD) and LOV (Light oxygen voltage) photoreceptor domains.
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Affiliation(s)
- Tilo Mathes
- Department of Physics, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1081, Amsterdam, 1081HV, The Netherlands
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47
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Brust R, Lukacs A, Haigney A, Addison K, Gil A, Towrie M, Clark IP, Greetham G, Tonge PJ, Meech SR. Proteins in action: femtosecond to millisecond structural dynamics of a photoactive flavoprotein. J Am Chem Soc 2013; 135:16168-74. [PMID: 24083781 PMCID: PMC3837517 DOI: 10.1021/ja407265p] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Indexed: 01/07/2023]
Abstract
Living systems are fundamentally dependent on the ability of proteins to respond to external stimuli. The mechanism, the underlying structural dynamics, and the time scales for regulation of this response are central questions in biochemistry. Here we probe the structural dynamics of the BLUF domain found in several photoactive flavoproteins, which is responsible for light activated functions as diverse as phototaxis and gene regulation. Measurements have been made over 10 decades of time (from 100 fs to 1 ms) using transient vibrational spectroscopy. Chromophore (flavin ring) localized dynamics occur on the pico- to nanosecond time scale, while subsequent protein structural reorganization is observed over microseconds. Multiple time scales are observed for the dynamics associated with different vibrations of the protein, suggesting an underlying hierarchical relaxation pathway. Structural evolution in residues directly H-bonded to the chromophore takes place more slowly than changes in more remote residues. However, a point mutation which suppresses biological function is shown to 'short circuit' this structural relaxation pathway, suppressing the changes which occur further away from the chromophore while accelerating dynamics close to it.
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Affiliation(s)
- Richard Brust
- Department
of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Andras Lukacs
- School
of Chemistry, University of East Anglia,
Norwich Research Park, Norwich NR4 7TJ, United Kingdom
- Department
of Biophysics, Medical School, University
of Pecs, Szigeti ut 12, 7624 Pecs, Hungary
| | - Allison Haigney
- Department
of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Kiri Addison
- School
of Chemistry, University of East Anglia,
Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Agnieszka Gil
- Department
of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Michael Towrie
- Central
Laser Facility, Research Complex at Harwell, Harwell Science and Innovation Campus, Didcot, Oxon OX11
0QX, United Kingdom
| | - Ian P. Clark
- Central
Laser Facility, Research Complex at Harwell, Harwell Science and Innovation Campus, Didcot, Oxon OX11
0QX, United Kingdom
| | - Gregory
M. Greetham
- Central
Laser Facility, Research Complex at Harwell, Harwell Science and Innovation Campus, Didcot, Oxon OX11
0QX, United Kingdom
| | - Peter J. Tonge
- Department
of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Stephen R. Meech
- School
of Chemistry, University of East Anglia,
Norwich Research Park, Norwich NR4 7TJ, United Kingdom
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48
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Kennis JTM, van Stokkum IHM, Peterson DS, Pandit A, Wachter RM. Ultrafast proton shuttling in Psammocora cyan fluorescent protein. J Phys Chem B 2013; 117:11134-43. [PMID: 23534404 DOI: 10.1021/jp401114e] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Cyan, green, yellow, and red fluorescent proteins (FPs) homologous to green fluorescent protein (GFP) are used extensively as model systems to study fundamental processes in photobiology, such as the capture of light energy by protein-embedded chromophores, color tuning by the protein matrix, energy conversion by Förster resonance energy transfer (FRET), and excited-state proton transfer (ESPT) reactions. Recently, a novel cyan fluorescent protein (CFP) termed psamFP488 was isolated from the genus Psammocora of reef building corals. Within the cyan color class, psamFP488 is unusual because it exhibits a significantly extended Stokes shift. Here, we applied ultrafast transient absorption and pump-dump-probe spectroscopy to investigate the mechanistic basis of psamFP488 fluorescence, complemented with fluorescence quantum yield and dynamic light scattering measurements. Transient absorption spectroscopy indicated that, upon excitation at 410 nm, the stimulated cyan emission rises in 170 fs. With pump-dump-probe spectroscopy, we observe a very short-lived (110 fs) ground-state intermediate that we assign to the deprotonated, anionic chromophore. In addition, a minor fraction (14%) decays with 3.5 ps to the ground state. Structural analysis of homologous proteins indicates that Glu-167 is likely positioned in sufficiently close vicinity to the chromophore to act as a proton acceptor. Our findings support a model where unusually fast ESPT from the neutral chromophore to Glu-167 with a time constant of 170 fs and resulting emission from the anionic chromophore forms the basis of the large psamFP488 Stokes shift. When dumped to the ground state, the proton on neutral Glu is very rapidly shuttled back to the anionic chromophore in 110 fs. Proton shuttling in excited and ground states is a factor of 20-4000 faster than in GFP, which probably results from a favorable hydrogen-bonding geometry between the chromophore phenolic oxygen and the glutamate acceptor, possibly involving a short hydrogen bond. At any time in the reaction, the proton is localized on either the chromophore or Glu-167, which implies that most likely no low-barrier hydrogen bond exists between these molecular groups. This work supports the notion that proton transfer in biological systems, be it in an electronic excited or ground state, can be an intrinsically fast process that occurs on a 100 fs time scale. PsamFP488 represents an attractive model system that poses an ultrafast proton transfer regime in discrete steps. It constitutes a valuable model system in addition to wild type GFP, where proton transfer is relatively slow, and the S65T/H148D GFP mutant, where the effects of low-barrier hydrogen bonds dominate.
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Affiliation(s)
- John T M Kennis
- Department of Physics and Astronomy and LaserLaB, Faculty of Sciences, Vrije Universiteit , De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
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49
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Zhu J, Paparelli L, Hospes M, Arents J, Kennis JTM, van Stokkum IHM, Hellingwerf KJ, Groot ML. Photoionization and Electron Radical Recombination Dynamics in Photoactive Yellow Protein Investigated by Ultrafast Spectroscopy in the Visible and Near-Infrared Spectral Region. J Phys Chem B 2013; 117:11042-8. [DOI: 10.1021/jp311906f] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Jingyi Zhu
- Department
of Physics and Astronomy,
Faculty of Sciences, VU University, De
Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Laura Paparelli
- Department
of Physics and Astronomy,
Faculty of Sciences, VU University, De
Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Marijke Hospes
- Laboratory for Microbiology,
Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The
Netherlands
| | - Jos Arents
- Laboratory for Microbiology,
Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The
Netherlands
| | - John T. M. Kennis
- Department
of Physics and Astronomy,
Faculty of Sciences, VU University, De
Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Ivo H. M. van Stokkum
- Department
of Physics and Astronomy,
Faculty of Sciences, VU University, De
Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Klaas J. Hellingwerf
- Laboratory for Microbiology,
Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The
Netherlands
| | - Marie Louise Groot
- Department
of Physics and Astronomy,
Faculty of Sciences, VU University, De
Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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50
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Udvarhelyi A, Domratcheva T. Glutamine Rotamers in BLUF Photoreceptors: A Mechanistic Reappraisal. J Phys Chem B 2013; 117:2888-97. [DOI: 10.1021/jp400437x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Anikó Udvarhelyi
- Department of Biomolecular
Mechanisms, Max Planck Institute for Medical Research, Jahnstraße
29, 69120 Heidelberg, Germany
| | - Tatiana Domratcheva
- Department of Biomolecular
Mechanisms, Max Planck Institute for Medical Research, Jahnstraße
29, 69120 Heidelberg, Germany
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