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Cherepanov DA, Shelaev IV, Gostev FE, Nadtochenko VA, Xu W, Golbeck JH, Semenov AY. Symmetry breaking in photosystem I: ultrafast optical studies of variants near the accessory chlorophylls in the A- and B-branches of electron transfer cofactors. Photochem Photobiol Sci 2021; 20:1209-1227. [PMID: 34478050 DOI: 10.1007/s43630-021-00094-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 08/18/2021] [Indexed: 11/25/2022]
Abstract
Femtosecond absorption spectroscopy of Photosystem I (PS I) complexes from the cyanobacterium Synechocystis sp. PCC 6803 was carried out on three pairs of complementary amino acid substitutions located near the second pair of chlorophyll molecules Chl2A and Chl2B (also termed A-1A and A-1B). The absorption dynamics at delays of 0.1-500 ps were analyzed by decomposition into discrete decay-associated spectra and continuously distributed exponential components. The multi-exponential deconvolution of the absorption changes revealed that the electron transfer reactions in the PsaA-N600M, PsaA-N600H, and PsaA-N600L variants near the B-branch of cofactors are similar to those of the wild type, while the PsaB-N582M, PsaB-N582H, and PsaB-N582L variants near the A-branch of cofactors cause significant alterations of the photochemical processes, making them heterogeneous and poorly described by a discrete exponential kinetic model. A redistribution of the unpaired electron between the second and the third monomers Chl2A/Chl2B and Chl3A/Chl3B was identified in the time range of 9-20 ps, and the subsequent reduction of A1 was identified in the time range of 24-70 ps. In the PsaA-N600L and PsaB-N582H/L variants, the reduction of A1 occurred with a decreased quantum yield of charge separation. The decreased quantum yield correlates with a slowing of the phylloquinone A0 → A1 reduction, but not with the initial transient spectra measured at the shortest time delay. The results support a branch competition model, where the electron is sheared between Chl2A-Chl3A and Chl2B-Chl3B cofactors before its transfer to phylloquinone in either A1A or A1B sites.
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Affiliation(s)
- Dmitry A Cherepanov
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Kosygina St. 4, Moscow, 117977, Russian Federation.
| | - Ivan V Shelaev
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Kosygina St. 4, Moscow, 117977, Russian Federation
| | - Fedor E Gostev
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Kosygina St. 4, Moscow, 117977, Russian Federation
| | - Victor A Nadtochenko
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Kosygina St. 4, Moscow, 117977, Russian Federation.,Department of Chemistry, Lomonosov Moscow State University, Leninskiye Gory 1-3, Moscow, 119991, Russian Federation
| | - Wu Xu
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, LA, 70504, USA
| | - John H Golbeck
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, 16801, USA.,Department of Chemistry, The Pennsylvania State University, University Park, PA, 16801, USA
| | - Alexey Yu Semenov
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Kosygina St. 4, Moscow, 117977, Russian Federation.,A.N. Belozersky Institute of Physical-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, 1, Moscow, 119992, Russian Federation
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Mechanism of adiabatic primary electron transfer in photosystem I: Femtosecond spectroscopy upon excitation of reaction center in the far-red edge of the QY band. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:895-905. [DOI: 10.1016/j.bbabio.2017.08.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 08/14/2017] [Accepted: 08/16/2017] [Indexed: 11/23/2022]
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Shelaev I, Gorka M, Savitsky A, Kurashov V, Mamedov M, Gostev F, Möbius K, Nadtochenko V, Golbeck J, Semenov A. Effect of Dehydrated Trehalose Matrix on the Kinetics of Forward Electron Transfer Reactions in Photosystem I. ACTA ACUST UNITED AC 2016. [DOI: 10.1515/zpch-2016-0860] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Abstract
The effect of dehydration on the kinetics of forward electron transfer (ET) has been studied in cyanobacterial photosystem I (PS I) complexes in a trehalose glassy matrix by time-resolved optical and EPR spectroscopies in the 100 fs to 1 ms time domain. The kinetics of the flash-induced absorption changes in the subnanosecond time domain due to primary and secondary charge separation steps were monitored by pump–probe laser spectroscopy with 20-fs low-energy pump pulses centered at 720 nm. The back-reaction kinetics of P700 were measured by high-field time-resolved EPR spectroscopy and the forward kinetics of
A
1A
•
−
/
A
1
B
•
−
→
F
X
${\rm{A}}_{{\rm{1A}}}^{ \bullet - }/{\rm{A}}_{1{\rm{B}}}^{ \bullet - } \to {{\rm{F}}_{\rm{X}}}$
by time-resolved optical spectroscopy at 480 nm. The kinetics of the primary ET reactions to form the primary
P
700
•
+
A
0
•
−
${\rm{P}}_{700}^{ \bullet + }{\rm{A}}_0^{ \bullet - }$
and the secondary
P
700
•
+
A
1
•
−
${\rm{P}}_{700}^{ \bullet + }{\rm{A}}_1^{ \bullet - }$
ion radical pairs were not affected by dehydration in the trehalose matrix, while the yield of the
P
700
•
+
A
1
•
−
${\rm{P}}_{700}^{ \bullet + }{\rm{A}}_1^{ \bullet - }$
was decreased by ~20%. Forward ET from the phylloquinone molecules in the
A
1
A
•
−
${\rm{A}}_{1{\rm{A}}}^{ \bullet - }$
and
A
1
B
•
−
${\rm{A}}_{1{\rm{B}}}^{ \bullet - }$
sites to the iron–sulfur cluster FX slowed from ~220 ns and ~20 ns in solution to ~13 μs and ~80 ns, respectively. However, as shown by EPR spectroscopy, the ~15 μs kinetic phase also contains a small contribution from the recombination between
A
1
B
•
−
${\rm{A}}_{1{\rm{B}}}^{ \bullet - }$
and
P
700
•
+
.
${\rm{P}}_{700}^{ \bullet + }.$
These data reveal that the initial ET reactions from P700 to secondary phylloquinone acceptors in the A- and B-branches of cofactors (A1A and A1B) remain unaffected whereas ET beyond A1A and A1B is slowed or prevented by constrained protein dynamics due to the dry trehalose glass matrix.
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Affiliation(s)
- Ivan Shelaev
- N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, ul. Kosygina 4, 119991 Moscow, Russian Federation
| | - Michael Gorka
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, United States of America
| | - Anton Savitsky
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany , Phone: 0049-208-3063555, Fax: 0049-208-3063955
| | - Vasily Kurashov
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, United States of America
| | - Mahir Mamedov
- A.N. Belozersky Institute of Physical–Chemical Biology, Moscow State University, Moscow, Leninskie Gory, Moscow 119992, Russian Federation
| | - Fedor Gostev
- N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, ul. Kosygina 4, 119991 Moscow, Russian Federation
| | - Klaus Möbius
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstr. 34-36, D-45470 Mülheim an der Ruhr, Germany
- Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany
| | - Victor Nadtochenko
- N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, ul. Kosygina 4, 119991 Moscow, Russian Federation
| | - John Golbeck
- Department of Biochemistry and Molecular Biology, Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, United States of America
| | - Alexey Semenov
- N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, ul. Kosygina 4, 119991 Moscow, Russian Federation
- A.N. Belozersky Institute of Physical–Chemical Biology, Moscow State University, Moscow, Leninskie Gory, Moscow 119992, Russian Federation
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McConnell MD, Cowgill JB, Baker PL, Rappaport F, Redding KE. Double reduction of plastoquinone to plastoquinol in photosystem 1. Biochemistry 2011; 50:11034-46. [PMID: 22103567 DOI: 10.1021/bi201131r] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In Photosystem 1 (PS1), phylloquinone (PhQ) acts as a secondary electron acceptor from chlorophyll ec(3) and also as an electron donor to the iron-sulfur cluster F(X). PS1 possesses two virtually equivalent branches of electron transfer (ET) cofactors from P(700) to F(X), and the lifetime of the semiquinone intermediate displays biphasic kinetics, reflecting ET along the two different branches. PhQ in PS1 serves only as an intermediate in ET and is not normally fully reduced to the quinol form. This is in contrast to PS2, in which plastoquinone (PQ) is doubly reduced to plastoquinol (PQH(2)) as the terminal electron acceptor. We purified PS1 particles from the menD1 mutant of Chlamydomonas reinhardtii that cannot synthesize PhQ, resulting in replacement of PhQ by PQ in the quinone-binding pocket. The magnitude of the stable flash-induced P(700)(+) signal of menD1 PS1, but not wild-type PS1, decreased during a train of laser flashes, as it was replaced by a ~30 ns back-reaction from the preceding radical pair (P(700)(+)A(0)(-)). We show that this process of photoinactivation is due to double reduction of PQ in the menD1 PS1 and have characterized the process. It is accelerated at lower pH, consistent with a rate-limiting protonation step. Moreover, a point mutation (PsaA-L722T) in the PhQ(A) site that accelerates ET to F(X) ~2-fold, likely by weakening the sole H-bond to PhQ(A), also accelerates the photoinactivation process. The addition of exogenous PhQ can restore activity to photoinactivated PS1 and confer resistance to further photoinactivation. This process also occurs with PS1 purified from the menB PhQ biosynthesis mutant of Synechocystis PCC 6803, demonstrating that it is a general phenomenon in both prokaryotic and eukaryotic PS1.
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Affiliation(s)
- Michael D McConnell
- Department of Chemistry and Biochemistry and Center for Bioenergy and Photosynthesis, Arizona State University, Tempe, Arizona 85287-1604, United States.
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Femtosecond primary charge separation in Synechocystis sp. PCC 6803 photosystem I. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1410-20. [PMID: 20219440 DOI: 10.1016/j.bbabio.2010.02.026] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2009] [Revised: 01/25/2010] [Accepted: 02/23/2010] [Indexed: 11/21/2022]
Abstract
The ultrafast (<100 fs) conversion of delocalized exciton into charge-separated state between the primary donor P700 (bleaching at 705 nm) and the primary acceptor A0 (bleaching at 690 nm) in photosystem I (PS I) complexes from Synechocystis sp. PCC 6803 was observed. The data were obtained by application of pump-probe technique with 20-fs low-energy pump pulses centered at 720 nm. The earliest absorbance changes (close to zero delay) with a bleaching at 690 nm are similar to the product of the absorption spectrum of PS I complex and the laser pulse spectrum, which represents the efficiency spectrum of the light absorption by PS I upon femtosecond excitation centered at 720 nm. During the first approximately 60 fs the energy transfer from the chlorophyll (Chl) species bleaching at 690 nm to the Chl bleaching at 705 nm occurs, resulting in almost equal bleaching of the two forms with the formation of delocalized exciton between 690-nm and 705-nm Chls. Within the next approximately 40 fs the formation of a new broad band centered at approximately 660 nm (attributed to the appearance of Chl anion radical) is observed. This band decays with time constant simultaneously with an electron transfer to A1 (phylloquinone). The subtraction of kinetic difference absorption spectra of the closed (state P700+A0A1) PS I reaction center (RC) from that of the open (state P700A0A1) RC reveals the pure spectrum of the P700+A0- ion-radical pair. The experimental data were analyzed using a simple kinetic scheme: An*-->k1[(PA0)*A1--><100 fs P+A0-A1]-->k2P+A0A1-, and a global fitting procedure based on the singular value decomposition analysis. The calculated kinetics of transitions between intermediate states and their spectra were similar to the kinetics recorded at 694 and 705 nm and the experimental spectra obtained by subtraction of the spectra of closed RCs from the spectra of open RCs. As a result, we found that the main events in RCs of PS I under our experimental conditions include very fast (<100 fs) charge separation with the formation of the P700+A0-A1 state in approximately one half of the RCs, the approximately 5-ps energy transfer from antenna Chl* to P700A0A1 in the remaining RCs, and approximately 25-ps formation of the secondary radical pair P700+A0A1-.
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Srinivasan N, Golbeck JH. Protein–cofactor interactions in bioenergetic complexes: The role of the A1A and A1B phylloquinones in Photosystem I. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1787:1057-88. [DOI: 10.1016/j.bbabio.2009.04.010] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Revised: 04/14/2009] [Accepted: 04/22/2009] [Indexed: 10/20/2022]
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Giera W, Gibasiewicz K, Ramesh VM, Lin S, Webber A. Electron transfer from A−0 to A1 in Photosystem I from Chlamydomonas reinhardtii occurs in both the A and B branch with 25–30-ps lifetime. Phys Chem Chem Phys 2009; 11:5186-91. [DOI: 10.1039/b822938d] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Zhbanko M, Zinchenko V, Gutensohn M, Schierhorn A, Klösgen RB. Inactivation of a predicted leader peptidase prevents photoautotrophic growth of Synechocystis sp. strain PCC 6803. J Bacteriol 2005; 187:3071-8. [PMID: 15838034 PMCID: PMC1082817 DOI: 10.1128/jb.187.9.3071-3078.2005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To establish the role of the two putative type I leader peptidases (LepB1 and LepB2) encoded in the genome of the cyanobacterium Synechocystis sp. strain PCC 6803, we generated independent knockout mutants for both genes by introducing kanamycin resistance cassettes into the two open reading frames (sll0716 [lepB1] and slr1377 [lepB2], respectively). Although the insertion was successful in both instances, it was not possible to select homozygous mutant cells for lepB2, suggesting that the function of this gene is essential for cell viability. In contrast, LepB1 is apparently essential only for photoautotrophic growth, because homozygous lepB1::Km(r) cells could be propagated under heterotrophic conditions. They were even capable to some extent of photosynthetic oxygen evolution. However, the photosynthetic activity decreased gradually with extended incubation in the light and was particularly affected by high light intensities. Both features were indicative of photooxidative damage, which was probably caused by inefficient replacement of damaged components of the photosynthetic machinery due to the lack of a leader peptidase removing the signal peptides from photosynthetic precursor proteins. Indeed, processing of the PsbO precursor polypeptide to the corresponding mature protein was significantly affected in the mutant, and reduced amounts of other proteins that are synthesized as precursors with signal peptides accumulated in the cells. These results strongly suggest that LepB1 is important for removal of the signal peptides after membrane transport of the components of the photosynthetic machinery, which in turn is a prerequisite for the biogenesis of a functional photosynthetic electron transport chain.
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Affiliation(s)
- Maria Zhbanko
- Institut für Pflanzenphysiologie, Martin-Luther-Universität Halle-Wittenberg, Weinbergweg 10, 06120 Halle/Saale, Germany
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Abstract
This mini-review focuses on recent experimental results and questions, which came up since the last more comprehensive reviews on the subject. We include a brief discussion of the different techniques used for time-resolved studies of electron transfer in photosystem I (PS I) and relate the kinetic results to new structural data of the PS I reaction centre.
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Affiliation(s)
- K Brettel
- Section de Bioénergétique and CNRS URA 2096, Département de Biologie Cellulaire et Moléculaire, CEA Saclay, 91191 Cedex, Gif-sur-Yvette, France.
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