1
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Kang XW, Wang K, Zhang X, Zhong D, Ding B. Elementary Reactions in the Functional Triads of the Blue-Light Photoreceptor BLUF Domain. J Phys Chem B 2024; 128:2065-2075. [PMID: 38391132 DOI: 10.1021/acs.jpcb.3c07988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
The blue light using the flavin (BLUF) domain is one of the smallest photoreceptors in nature, which consists of a unique bidirectional electron-coupled proton relay process in its photoactivation reaction cycle. This perspective summarizes our recent efforts in dissecting the photocycle into three elementary processes, including proton-coupled electron transfer (PCET), proton rocking, and proton relay. Using ultrafast spectroscopy, we have determined the temporal sequence, rates, kinetic isotope effects (KIEs), and concertedness of these elementary steps. Our findings provide important implications for illuminating the photoactivation mechanism of the BLUF domain and suggest an engineering platform to characterize intricate reactions involving proton motions that are ubiquitous in nonphotosensitive protein machines.
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Affiliation(s)
- Xiu-Wen Kang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Kailin Wang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Xiaofan Zhang
- 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, Programs of Chemical Physics, and Programs of Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Bei Ding
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
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2
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Chretien A, Nagel MF, Botha S, de Wijn R, Brings L, Dörner K, Han H, Koliyadu JCP, Letrun R, Round A, Sato T, Schmidt C, Secareanu RC, von Stetten D, Vakili M, Wrona A, Bean R, Mancuso A, Schulz J, Pearson AR, Kottke T, Lorenzen K, Schubert R. Light-induced Trp in/Met out Switching During BLUF Domain Activation in ATP-bound Photoactivatable Adenylate Cyclase OaPAC. J Mol Biol 2024; 436:168439. [PMID: 38185322 DOI: 10.1016/j.jmb.2024.168439] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/28/2023] [Accepted: 01/03/2024] [Indexed: 01/09/2024]
Abstract
The understanding of signal transduction mechanisms in photoreceptor proteins is essential for elucidating how living organisms respond to light as environmental stimuli. In this study, we investigated the ATP binding, photoactivation and signal transduction process in the photoactivatable adenylate cyclase from Oscillatoria acuminata (OaPAC) upon blue light excitation. Structural models with ATP bound in the active site of native OaPAC at cryogenic as well as room temperature are presented. ATP is found in one conformation at cryogenic- and in two conformations at ambient-temperature, and is bound in an energetically unfavorable conformation for the conversion to cAMP. However, FTIR spectroscopic experiments confirm that this conformation is the native binding mode in dark state OaPAC and that transition to a productive conformation for ATP turnover only occurs after light activation. A combination of time-resolved crystallography experiments at synchrotron and X-ray Free Electron Lasers sheds light on the early events around the Flavin Adenine Dinucleotide (FAD) chromophore in the light-sensitive BLUF domain of OaPAC. Early changes involve the highly conserved amino acids Tyr6, Gln48 and Met92. Crucially, the Gln48 side chain performs a 180° rotation during activation, leading to the stabilization of the FAD chromophore. Cryo-trapping experiments allowed us to investigate a late light-activated state of the reaction and revealed significant conformational changes in the BLUF domain around the FAD chromophore. In particular, a Trpin/Metout transition upon illumination is observed for the first time in the BLUF domain and its role in signal transmission via α-helix 3 and 4 in the linker region between sensor and effector domain is discussed.
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Affiliation(s)
- Anaïs Chretien
- European XFEL GmbH, Schenefeld, Germany; Department of Chemistry, Universität Hamburg, Hamburg, Germany
| | - Marius F Nagel
- Department of Chemistry and Medical School OWL, Bielefeld University, Bielefeld, Germany
| | - Sabine Botha
- Department of Physics, Arizona State University, Tempe, AZ 85287-1504, USA; Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ 85287-5001, USA
| | | | | | | | | | | | | | | | | | | | | | - David von Stetten
- European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
| | | | | | | | | | | | - Arwen R Pearson
- Institute for Nanostructure and Solid-State Physics, Universität Hamburg, Hamburg, Germany
| | - Tilman Kottke
- Department of Chemistry and Medical School OWL, Bielefeld University, Bielefeld, Germany
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3
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Zhou Y, Tang S, Chen Z, Zhou Z, Huang J, Kang XW, Zou S, Wang B, Zhang T, Ding B, Zhong D. Origin of the multi-phasic quenching dynamics in the BLUF domains across the species. Nat Commun 2024; 15:623. [PMID: 38245518 PMCID: PMC10799861 DOI: 10.1038/s41467-023-44565-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 12/19/2023] [Indexed: 01/22/2024] Open
Abstract
Blue light using flavin (BLUF) photoreceptors respond to light via one of nature's smallest photo-switching domains. Upon photo-activation, the flavin cofactor in the BLUF domain exhibits multi-phasic dynamics, quenched by a proton-coupled electron transfer reaction involving the conserved Tyr and Gln. The dynamic behavior varies drastically across different species, the origin of which remains controversial. Here, we incorporate site-specific fluorinated Trp into three BLUF proteins, i.e., AppA, OaPAC and SyPixD, and characterize the percentages for the Wout, WinNHin and WinNHout conformations using 19F nuclear magnetic resonance spectroscopy. Using femtosecond spectroscopy, we identify that one key WinNHin conformation can introduce a branching one-step proton transfer in AppA and a two-step proton transfer in OaPAC and SyPixD. Correlating the flavin quenching dynamics with the active-site structural heterogeneity, we conclude that the quenching rate is determined by the percentage of WinNHin, which encodes a Tyr-Gln configuration that is not conducive to proton transfer.
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Affiliation(s)
- 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
| | - 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
| | - Jiulong Huang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xiu-Wen Kang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Shuhua Zou
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Bingyao Wang
- 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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4
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Noji T, Tamura H, Ishikita H, Saito K. Difference in the Charge-Separation Energetics between Distinct Conformers in the PixD Photoreceptor. J Phys Chem B 2023; 127:10351-10359. [PMID: 38014591 DOI: 10.1021/acs.jpcb.3c06483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Blue light using flavin (BLUF) domain proteins are photoreceptors in various organisms. The PixD BLUF domain can adopt two conformations, W91out and W91in, with Trp91 either proximal or distal to flavin (FMN). Using a quantum mechanical/molecular mechanical/polarizable continuum model approach, the energetics of charge-separated and biradical states in the two conformations were investigated. In the W91out conformation, the charge-separated state (FMN•-) is more stable than the photoexcited state (FMN*), whereas it is less stable due to an electrostatic repulsive interaction with the Ser28 side chain in the W91in conformation. This leads to a lower activation energy for the charge separation in the W91out conformation, resulting in a faster charge separation compared to that in the W91in conformation. In the W91out conformation, the radical state (FMNH•) is more stable than FMN•- and forms from FMN•-, leading to reorientation of the Gln50 side chain adjacent to FMN and formation of a hydrogen bond between Gln50 and FMN. Subsequently, a signaling state forms through charge recombination. In contrast, in the W91in conformation, FMN•- cannot proceed further, returning to the dark-adapted state, as FMNH• is less stable. Thus, formation of the signaling state exclusively occurs in the W91out conformation.
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Affiliation(s)
- Tomoyasu Noji
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Hiroyuki Tamura
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Hiroshi Ishikita
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Keisuke Saito
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
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5
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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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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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7
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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: 9] [Impact Index Per Article: 4.5] [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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8
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Abstract
Light activated proteins are at the heart of photobiology and optogenetics, so there is wide interest in understanding the mechanisms coupling optical excitation to protein function. In addition, such light activated proteins provide unique insights into the real-time dynamics of protein function. Using pump-probe spectroscopy, the function of a photoactive protein can be initiated by a sub-100 fs pulse of light, allowing subsequent protein dynamics to be probed from femtoseconds to milliseconds and beyond. Among the most interesting photoactive proteins are the blue light using flavin (BLUF) domain proteins, which regulate the response to light of a wide range of bacterial and some euglenoid processes. The photosensing mechanism of BLUF domains has long been a subject of debate. In contrast to other photoactive proteins, the electronic and nuclear structure of the chromophore (flavin) is the same in dark- and light-adapted states. Thus, the driving force for photoactivity is unclear.To address this question requires real-time observation of both chromophore excited state processes and their effect on the structure and dynamics of the surrounding protein matrix. In this Account we describe how time-resolved infrared (IR) experiments, coupled with chemical biology, provide important new insights into the signaling mechanism of BLUF domains. IR measurements are sensitive to changes in both chromophore electronic structure and protein hydrogen bonding interactions. These contributions are resolved by isotope labeling of the chromophore and protein separately. Further, a degree of control over BLUF photochemistry is achieved through mutagenesis, while unnatural amino acid substitution allows us to both fine-tune the photochemistry and time resolve protein dynamics with spatial resolution.Ultrafast studies of BLUF domains reveal non-single-exponential relaxation of the flavin excited state. That relaxation leads within one nanosecond to the original flavin ground state bound in a modified hydrogen-bonding network, as seen in transient and steady-state IR spectroscopy. The change in H-bond configuration arises from formation of an unusual enol (imine) form of a critical glutamine residue. The dynamics observed, complemented by quantum mechanical calculations, suggest a unique sequential electron then double proton transfer reaction as the driving force, followed by rapid reorganization in the binding site and charge recombination. Importantly, studies of several BLUF domains reveal an unexpected diversity in their dynamics, although the underlying structure appears highly conserved. It is suggested that this diversity reflects structural dynamics in the ground state at standard temperature, leading to a distribution of structures and photochemical outcomes. Time resolved IR measurements were extended to the millisecond regime for one BLUF domain, revealing signaling state formation on the microsecond time scale. The mechanism involves reorganization of a β-sheet connected to the chromophore binding pocket via a tryptophan residue. The potential of site-specific labeling amino acids with IR labels as a tool for probing protein structural dynamics was demonstrated.In summary, time-resolved IR studies of BLUF domains (along with related studies at visible wavelengths and quantum and molecular dynamics calculations) have resolved the photoactivation mechanism and real-time dynamics of signaling state formation. These measurements provide new insights into protein structural dynamics and will be important in optimizing the potential of BLUF domains in optobiology.
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Affiliation(s)
- Andras Lukacs
- Department of Biophysics, Medical School, University of Pécs, Szigeti str 12, 7624 Pécs, Hungary
| | - Peter J. Tonge
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York 11794-3400, United States
| | - Stephen R. Meech
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U.K
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9
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Khrenova MG, Kulakova AM, Nemukhin AV. Light-Induced Change of Arginine Conformation Modulates the Rate of Adenosine Triphosphate to Cyclic Adenosine Monophosphate Conversion in the Optogenetic System Containing Photoactivated Adenylyl Cyclase. J Chem Inf Model 2021; 61:1215-1225. [PMID: 33677973 DOI: 10.1021/acs.jcim.0c01308] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We report the first computational characterization of an optogenetic system composed of two photosensing BLUF (blue light sensor using flavin adenine dinucleotide) domains and two catalytic adenylyl cyclase (AC) domains. Conversion of adenosine triphosphate (ATP) to the reaction products, cyclic adenosine monophosphate (cAMP) and pyrophosphate (PPi), catalyzed by ACs initiated by excitation in photosensing domains has emerged in the focus of modern optogenetic applications because of the request in photoregulated enzymes that modulate cellular concentrations of signaling messengers. The photoactivated AC from the soil bacterium Beggiatoa sp. (bPAC) is an important model showing a considerable increase in the ATP to cAMP conversion rate in the catalytic domain after the illumination of the BLUF domain. The 1 μs classical molecular dynamics simulations reveal that the activation of the BLUF domain leading to tautomerization of Gln49 in the chromophore-binding pocket results in switching of the position of the side chain of Arg278 in the active site of AC. Allosteric signal transmission pathways between Gln49 from BLUF and Arg278 from AC were revealed by the dynamical network analysis. The Gibbs energy profiles of the ATP → cAMP + PPi reaction computed using QM(DFT(ωB97X-D3/6-31G**))/MM(CHARMM) molecular dynamics simulations for both Arg278 conformations in AC clarify the reaction mechanism. In the light-activated system, the corresponding arginine conformation stabilizes the pentacoordinated phosphorus of the α-phosphate group in the transition state, thus lowering the activation energy. Simulations of the bPAC system with the Tyr7Phe replacement in the BLUF demonstrate occurrence of both arginine conformations in an equal ratio, explaining the experimentally observed intermediate catalytic activity of the bPAC-Y7F variant as compared with the dark and light states of the wild-type bPAC.
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Affiliation(s)
- Maria G Khrenova
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russian Federation.,Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Moscow 119071 Russian Federation
| | - Anna M Kulakova
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russian Federation
| | - Alexander V Nemukhin
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russian Federation.,Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow 119334, Russian Federation
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10
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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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11
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Modular Diversity of the BLUF Proteins and Their Potential for the Development of Diverse Optogenetic Tools. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9183924] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Organisms can respond to varying light conditions using a wide range of sensory photoreceptors. These photoreceptors can be standalone proteins or represent a module in multidomain proteins, where one or more modules sense light as an input signal which is converted into an output response via structural rearrangements in these receptors. The output signals are utilized downstream by effector proteins or multiprotein clusters to modulate their activity, which could further affect specific interactions, gene regulation or enzymatic catalysis. The blue-light using flavin (BLUF) photosensory module is an autonomous unit that is naturally distributed among functionally distinct proteins. In this study, we identified 34 BLUF photoreceptors of prokaryotic and eukaryotic origin from available bioinformatics sequence databases. Interestingly, our analysis shows diverse BLUF-effector arrangements with a functional association that was previously unknown or thought to be rare among the BLUF class of sensory proteins, such as endonucleases, tet repressor family (tetR), regulators of G-protein signaling, GAL4 transcription family and several other previously unidentified effectors, such as RhoGEF, Phosphatidyl-Ethanolamine Binding protein (PBP), ankyrin and leucine-rich repeats. Interaction studies and the indexing of BLUF domains further show the diversity of BLUF-effector combinations. These diverse modular architectures highlight how the organism’s behaviour, cellular processes, and distinct cellular outputs are regulated by integrating BLUF sensing modules in combination with a plethora of diverse signatures. Our analysis highlights the modular diversity of BLUF containing proteins and opens the possibility of creating a rational design of novel functional chimeras using a BLUF architecture with relevant cellular effectors. Thus, the BLUF domain could be a potential candidate for the development of powerful novel optogenetic tools for its application in modulating diverse cell signaling.
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12
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Wood CR, Squire MS, Finley NL, Page RC, Actis LA. Structural and functional analysis of the Acinetobacter baumannii BlsA photoreceptor and regulatory protein. PLoS One 2019; 14:e0220918. [PMID: 31415622 PMCID: PMC6695109 DOI: 10.1371/journal.pone.0220918] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 07/25/2019] [Indexed: 12/22/2022] Open
Abstract
The Acinetobacter baumannii BlsA photoreceptor has an N-terminal (NT) BLUF domain and a C-terminal (CT) amino acid sequence with no significant homology to characterized bacterial proteins. In this study, we tested the biological role of specific residues located in these BlsA regions. Site-directed mutagenesis, surface motility assays at 24°C and protein overexpression showed that residues Y7, Q51 and W92 are essential for not only light-regulated motility, but also BlsA's solubility when overexpressed in a heterologous host. In contrast, residues A29 and F32, the latter representing a difference when compared with other BLUF-containing photoreceptors, do not play a major role in BlsA's biological functions. Analysis of the CT region showed that the deletion of the last five BlsA residues has no significant effect on the protein's light-sensing and motility regulatory functions, but the deletion of the last 14 residues as well as K144E and K145E substitutions significantly alter light-regulated motility responses. In contrast to the NT mutants, these CT derivatives were overexpressed and purified to homogeneity to demonstrate that although these mutations do not significantly affect flavin binding and photocycling, they do affect BlsA's photodynamic properties. Notably, these mutations map within a potential fifth α-helical component that could play a role in predicted interactions between regulatory partners and BlsA, which could function as a monomer according to gel filtration data. All these observations indicate that although BlsA shares common structural and functional properties with unrelated photoreceptors, it also exhibits unique features that make it a distinct BLUF photoreceptor.
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Affiliation(s)
- Cecily R. Wood
- Department of Microbiology, Miami University, Oxford, Ohio, United States of America
| | - Mariah S. Squire
- Department of Microbiology, Miami University, Oxford, Ohio, United States of America
| | - Natosha L. Finley
- Department of Microbiology, Miami University, Oxford, Ohio, United States of America
| | - Richard C. Page
- Department of Chemistry and Biochemistry, Miami University, Oxford, Ohio, United States of America
| | - Luis A. Actis
- Department of Microbiology, Miami University, Oxford, Ohio, United States of America
- * E-mail:
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13
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Light-based control of metabolic flux through assembly of synthetic organelles. Nat Chem Biol 2019; 15:589-597. [PMID: 31086330 PMCID: PMC6755918 DOI: 10.1038/s41589-019-0284-8] [Citation(s) in RCA: 147] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 04/01/2019] [Indexed: 11/21/2022]
Abstract
To maximize a desired product, metabolic engineers typically express enzymes to high, constant levels. Yet permanent pathway activation can have undesirable consequences including competition with essential pathways and accumulation of toxic intermediates. Faced with similar challenges, natural metabolic systems compartmentalize enzymes into organelles or post-translationally induce activity under certain conditions. Here, we report that optogenetic control can be used to extend compartmentalization and dynamic control to engineered metabolisms in yeast. We describe a suite of optogenetic tools to trigger assembly and disassembly of metabolically-active enzyme clusters. Using the deoxyviolacein biosynthesis pathway as a model system, we find that light-switchable clustering can enhance product formation by six-fold and product specificity by 18-fold by decreasing the concentration of intermediate metabolites and reducing flux through competing pathways. Inducible compartmentalization of enzymes into synthetic organelles can thus be used to control engineered metabolic pathways, limit intermediates and favor the formation of desired products.
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14
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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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15
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Nakajima T, Kuroi K, Nakasone Y, Okajima K, Ikeuchi M, Tokutomi S, Terazima M. Anomalous pressure effects on the photoreaction of a light-sensor protein from Synechocystis, PixD (Slr1694), and the compressibility change of its intermediates. Phys Chem Chem Phys 2018; 18:25915-25925. [PMID: 27711633 DOI: 10.1039/c6cp05091c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
SyPixD (Slr1694) is a blue-light receptor that contains a BLUF (blue-light sensor using a flavin chromophore) domain for the function of phototaxis. The key reaction of this protein is a light-induced conformational change and subsequent dissociation reaction from the decamer to the dimer. In this study, anomalous effects of pressure on this reaction were discovered, and changes in the compressibility of its short-lived intermediates were investigated. While the absorption spectra of the dark and light states are not sensitive to pressure, the formation yield of the first intermediate decreases with pressure to about 40% at 150 MPa. Upon blue-light illumination with a sufficiently strong intensity, the transient grating signal, which represents the dissociation of the SyPixD decamer, was observed at 0.1 MPa, and the signal intensity significantly decreased with increasing pressure. This behavior shows that the dissociation of the decamer from the second intermediate state is suppressed by pressure. However, while the decamer undergoes no dissociation upon excitation of one monomer unit at 0.1 MPa, dissociation is gradually induced with increasing pressure. For solving this strange behavior, the compressibility changes of the intermediates were measured as a function of pressure at weak light intensity. Interestingly, the compressibility change was negative at low pressure, but became positive with increasing pressure. Because the compressibility is related to the volume fluctuation, this observation suggests that the driving force for this reaction is fluctuation of the protein. The relationship between the cavities at the interfaces of the monomer units and the reactivity was also discussed.
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Affiliation(s)
- Tsubasa Nakajima
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
| | - Kunisato Kuroi
- 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.
| | - Koji Okajima
- Research Institute for Advanced Science and Technology, Department of Biological Science, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Masahiko Ikeuchi
- Department of Life Sciences (Biology), Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Tokyo 153-8902, Japan
| | - Satoru Tokutomi
- Research Institute for Advanced Science and Technology, Department of Biological Science, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Masahide Terazima
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
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16
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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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17
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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: 35] [Impact Index Per Article: 5.0] [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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18
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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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19
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Lindner R, Hartmann E, Tarnawski M, Winkler A, Frey D, Reinstein J, Meinhart A, Schlichting I. Photoactivation Mechanism of a Bacterial Light-Regulated Adenylyl Cyclase. J Mol Biol 2017; 429:1336-1351. [PMID: 28336405 DOI: 10.1016/j.jmb.2017.03.020] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 03/08/2017] [Accepted: 03/17/2017] [Indexed: 01/07/2023]
Abstract
Light-regulated enzymes enable organisms to quickly respond to changing light conditions. We characterize a photoactivatable adenylyl cyclase (AC) from Beggiatoa sp. (bPAC) that translates a blue light signal into the production of the second messenger cyclic AMP. bPAC contains a BLUF photoreceptor domain that senses blue light using a flavin chromophore, linked to an AC domain. We present a dark state crystal structure of bPAC that closely resembles the recently published structure of the homologous OaPAC from Oscillatoria acuminata. To elucidate the structural mechanism of light-dependent AC activation by the BLUF domain, we determined the crystal structures of illuminated bPAC and of a pseudo-lit state variant. We use hydrogen-deuterium exchange measurements of secondary structure dynamics and hypothesis-driven point mutations to trace the activation pathway from the chromophore in the BLUF domain to the active site of the cyclase. The structural changes are relayed from the residues interacting with the excited chromophore through a conserved kink of the BLUF β-sheet to a tongue-like extrusion of the AC domain that regulates active site opening and repositions catalytic residues. Our findings not only show the specific molecular pathway of photoactivation in BLUF-regulated ACs but also have implications for the general understanding of signaling in BLUF domains and of the activation of ACs.
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Affiliation(s)
- Robert Lindner
- Max Planck Institute for Medical Research, Jahnstr, 29, 69120 Heidelberg, Germany
| | - Elisabeth Hartmann
- Max Planck Institute for Medical Research, Jahnstr, 29, 69120 Heidelberg, Germany
| | - Miroslaw Tarnawski
- Max Planck Institute for Medical Research, Jahnstr, 29, 69120 Heidelberg, Germany
| | - Andreas Winkler
- Max Planck Institute for Medical Research, Jahnstr, 29, 69120 Heidelberg, Germany
| | - Daniel Frey
- Max Planck Institute for Medical Research, Jahnstr, 29, 69120 Heidelberg, Germany
| | - Jochen Reinstein
- Max Planck Institute for Medical Research, Jahnstr, 29, 69120 Heidelberg, Germany
| | - Anton Meinhart
- Max Planck Institute for Medical Research, Jahnstr, 29, 69120 Heidelberg, Germany
| | - Ilme Schlichting
- Max Planck Institute for Medical Research, Jahnstr, 29, 69120 Heidelberg, Germany.
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20
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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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21
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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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22
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Fraikin GY, Strakhovskaya MG, Belenikina NS, Rubin AB. Bacterial photosensory proteins: Regulatory functions and optogenetic applications. Microbiology (Reading) 2015. [DOI: 10.1134/s0026261715040086] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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23
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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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24
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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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25
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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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26
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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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27
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Brust R, Haigney A, Lukacs A, Gil A, Hossain S, Addison K, Lai CT, Towrie M, Greetham G, Clark IP, Illarionov B, Bacher A, Kim RR, Fischer M, Simmerling C, Meech SR, Tonge PJ. Ultrafast Structural Dynamics of BlsA, a Photoreceptor from the Pathogenic Bacterium Acinetobacter baumannii. J Phys Chem Lett 2014; 5:220-224. [PMID: 24723998 PMCID: PMC3977573 DOI: 10.1021/jz4023738] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 12/06/2013] [Indexed: 06/03/2023]
Abstract
Acinetobacter baumannii is an important human pathogen that can form biofilms and persist under harsh environmental conditions. Biofilm formation and virulence are modulated by blue light, which is thought to be regulated by a BLUF protein, BlsA. To understand the molecular mechanism of light sensing, we have used steady-state and ultrafast vibrational spectroscopy to compare the photoactivation mechanism of BlsA to the BLUF photosensor AppA from Rhodobacter sphaeroides. Although similar photocycles are observed, vibrational data together with homology modeling identify significant differences in the β5 strand in BlsA caused by photoactivation, which are proposed to be directly linked to downstream signaling.
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Affiliation(s)
- Richard Brust
- Department
of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Allison Haigney
- 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, Pecs, Hungary
| | - Agnieszka Gil
- Department
of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Shahrier Hossain
- 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
| | - Cheng-Tsung Lai
- 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
| | - Gregory
M. Greetham
- 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
| | - Boris Illarionov
- Institut für
Biochemie und Lebensmittelchemie, Universität
Hamburg, Grindelallee
117, D-20146 Hamburg, Germany
| | - Adelbert Bacher
- Institut für
Biochemie und Lebensmittelchemie, Universität
Hamburg, Grindelallee
117, D-20146 Hamburg, Germany
| | - Ryu-Ryun Kim
- Institut für
Biochemie und Lebensmittelchemie, Universität
Hamburg, Grindelallee
117, D-20146 Hamburg, Germany
| | - Markus Fischer
- Institut für
Biochemie und Lebensmittelchemie, Universität
Hamburg, Grindelallee
117, D-20146 Hamburg, Germany
| | - Carlos Simmerling
- 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
| | - Peter J. Tonge
- Department
of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
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28
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Mehlhorn J, Steinocher H, Beck S, Kennis JTM, Hegemann P, Mathes T. A set of engineered Escherichia coli expression strains for selective isotope and reactivity labeling of amino acid side chains and flavin cofactors. PLoS One 2013; 8:e79006. [PMID: 24223875 PMCID: PMC3815312 DOI: 10.1371/journal.pone.0079006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 09/21/2013] [Indexed: 11/18/2022] Open
Abstract
Biological reactions are facilitated by delicate molecular interactions between proteins, cofactors and substrates. To study and understand their dynamic interactions researchers have to take great care not to influence or distort the object of study. As a non-invasive alternative to a site-directed mutagenesis approach, selective isotope labeling in combination with vibrational spectroscopy may be employed to directly identify structural transitions in wild type proteins. Here we present a set of customized Escherichia coli expression strains, suitable for replacing both the flavin cofactor and/or selective amino acids with isotope enriched or chemically modified substrates. For flavin labeling we report optimized auxotrophic strains with significantly enhanced flavin uptake properties. Labeled protein biosynthesis using these strains was achieved in optimized cultivation procedures using high cell density fermentation. Finally, we demonstrate how this approach is used for a clear assignment of vibrational spectroscopic difference signals of apoprotein and cofactor of a flavin containing photoreceptor of the BLUF (Blue Light receptors Using FAD) family.
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Affiliation(s)
- Jennifer Mehlhorn
- Institut für Biologie/Experimentelle Biophysik, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Helena Steinocher
- Institut für Biologie/Experimentelle Biophysik, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Sebastian Beck
- Institut für Chemie, Humboldt-Universität zu Berlin, Berlin, Germany
| | - John T. M. Kennis
- Biophysics Group, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, Amsterdam, The Netherlands
| | - Peter Hegemann
- Institut für Biologie/Experimentelle Biophysik, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Tilo Mathes
- Institut für Biologie/Experimentelle Biophysik, Humboldt-Universität zu Berlin, Berlin, Germany
- Biophysics Group, Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, Amsterdam, The Netherlands
- * E-mail:
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29
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Winkler A, Heintz U, Lindner R, Reinstein J, Shoeman RL, Schlichting I. A ternary AppA-PpsR-DNA complex mediates light regulation of photosynthesis-related gene expression. Nat Struct Mol Biol 2013; 20:859-67. [PMID: 23728293 PMCID: PMC3702404 DOI: 10.1038/nsmb.2597] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 04/10/2013] [Indexed: 11/09/2022]
Abstract
The anoxygenic phototrophic bacterium Rhodobacter sphaeroides uses different energy sources, depending on environmental conditions including aerobic respiration or, in the absence of oxygen, photosynthesis. Photosynthetic genes are repressed at high oxygen tension, but at intermediate levels their partial expression prepares the bacterium for using light energy. Illumination, however, enhances repression under semiaerobic conditions. Here, we describe molecular details of two proteins mediating oxygen and light control of photosynthesis-gene expression: the light-sensing antirepressor AppA and the transcriptional repressor PpsR. Our crystal structures of both proteins and their complex and hydrogen/deuterium-exchange data show that light activation of AppA-PpsR2 affects the PpsR effector region within the complex. DNA binding studies demonstrate the formation of a light-sensitive ternary AppA-PpsR-DNA complex. We discuss implications of these results for regulation by light and oxygen, highlighting new insights into blue light-mediated signal transduction.
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Affiliation(s)
- Andreas Winkler
- Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, Heidelberg, Germany.
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30
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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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31
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Ren S, Sato R, Hasegawa K, Ohta H, Masuda S. A predicted structure for the PixD-PixE complex determined by homology modeling, docking simulations, and a mutagenesis study. Biochemistry 2013; 52:1272-9. [PMID: 23346988 DOI: 10.1021/bi301004v] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PixD is a blue light-using flavin (BLUF) photoreceptor that controls phototaxis in the cyanobacterium Synechocystis sp. PCC6803. PixD interacts with the response regulator-like protein PixE in a light-dependent manner, and this interaction is critical for light signal transduction in vivo. However, the structure of the PixD-PixE complex has not been determined. To improve our understanding of how PixD transmits its captured light signal to PixE, we used blue-native polyacrylamide gel electrophoresis to characterize the molecular mass of a recombinant PixD-PixE complex purified from Escherichia coli and found it to be 342 kDa, suggesting that the complex contains 10 PixD and 4 PixE monomers. The stoichiometry of the complex was confirmed by Western blotting. Specifically, three intermediate states, PixD(10)-PixE(1), PixD(10)-PixE(2), and PixD(10)-PixE(3), were detected. The apparent dissociation constant for PixE and PixD is ~5 μM. A docking simulation was performed using a modeled PixE structure and the PixD(10) crystal structure. The docking simulation showed how the molecules in the PixD(10)-PixE(4) structure interact. To verify the accuracy of the docked model, a site-directed mutagenesis study was performed in which Arg80 of PixE, which appears to be capable of interacting electrostatically with Asp135 of PixD in the predicted structure, was shown to be critical for complex formation as mutation of PixE Arg80 to Asp or Ala prevented PixD-PixE complex formation. This study provides a structural basis for future investigations of the light signal transduction mechanism involving PixD and PixE.
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Affiliation(s)
- Shukun Ren
- Center for Biological Resources and Informatics, Tokyo Institute of Technology, Yokohama 226-8501, Japan
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32
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Tanaka K, Nakasone Y, Okajima K, Ikeuchi M, Tokutomi S, Terazima M. Time-Resolved Tracking of Interprotein Signal Transduction: Synechocystis PixD–PixE Complex as a Sensor of Light Intensity. J Am Chem Soc 2012; 134:8336-9. [DOI: 10.1021/ja301540r] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Keisuke Tanaka
- 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
| | - Koji Okajima
- Department
of Life Sciences
(Biology), Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Tokyo 153-8902, Japan
- Department of Biological Science,
Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Masahiko Ikeuchi
- Department
of Life Sciences
(Biology), Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Tokyo 153-8902, Japan
| | - Satoru Tokutomi
- Department of Biological Science,
Graduate School of Science, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Masahide Terazima
- Department of Chemistry, Graduate
School of Science, Kyoto University, Kyoto
606-8502, Japan
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33
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Losi A, Gärtner W. The evolution of flavin-binding photoreceptors: an ancient chromophore serving trendy blue-light sensors. ANNUAL REVIEW OF PLANT BIOLOGY 2012; 63:49-72. [PMID: 22136567 DOI: 10.1146/annurev-arplant-042811-105538] [Citation(s) in RCA: 140] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Photoreceptor flavoproteins of the LOV, BLUF, and cryptochrome families are ubiquitous among the three domains of life and are configured as UVA/blue-light systems not only in plants-their original arena-but also in prokaryotes and microscopic algae. Here, we review these proteins' structure and function, their biological roles, and their evolution and impact in the living world, and underline their growing application in biotechnologies. We present novel developments such as the interplay of light and redox stimuli, emerging enzymatic and biological functions, lessons on evolution from picoalgae, metagenomics analysis, and optogenetics applications.
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Affiliation(s)
- Aba Losi
- Department of Physics, University of Parma, Parma, Italy.
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