Breaking the Red Limit: Efficient Trapping of Long-Wavelength Excitations in Chlorophyll-f-Containing Photosystem I

Tros, Martijn; Mascoli, Vincenzo; Shen, Gaozhong; Ho, Ming Yang; Bersanini, Luca; Gisriel, Christopher J.; Bryant, Donald A.; Croce, Roberta

doi:10.1016/j.chempr.2020.10.024

Cited by 27 publications

(47 citation statements)

References 55 publications

(140 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Based on pigment analysis ( 37 , 38 ) (see Experimental procedures ) and deconvolution of low-temperature absorbance spectra ( 20 ), eight Chl f molecules are expected per Synechococcus 7335 FRL–PSI monomer. To gain insight into where Chl f might bind in the Synechococcus 7335 FRL-PSI structure, we mapped the sequence similarity between FRL and WL sequences to the FRL-specific subunits of the cryo-EM structure, which is shown in Figure 2 .…”

Section: Resultsmentioning

confidence: 99%

“…The Chl in site B38 is also axially ligated by a non-His sidechain but does not have a clear H-bond donor to the formyl moiety. However, this site forms a Chl dimer with B37 that was proposed to explain spectroscopic evidence for a Chl f dimer (20).…”

Section: Identification Of Binding Sites For Chl Fmentioning

confidence: 98%

“…Understanding FaRLiP, especially the insertion and function of Chl f molecules into the photosystems, has become a major interest to understand better the diversity of acclimation mechanisms for photosynthesis in nature and to harness the understanding of these processes to derive design principles for tuning light absorption in crop plants ( 17 , 18 ). To this end, various groups have used spectroscopic techniques and cryo-EM in attempts to identify the binding sites of Chl f in FRL-acclimated PSI (FRL-PSI) ( 14 , 16 , 19 , 20 ). Cryo-EM structures of FRL-PSI from Fischerella thermalis PCC 7521 ( Fischerella 7521) ( 14 , 15 ) and Halomicronema hongdechloris ( 16 ) have been reported, but identifying the Chl f sites has been challenging because of the minor chemical difference (Chl a has a methyl moiety at the C2 position, whereas Chl f has a formyl moiety at the C2 position.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Structure of a photosystem I-ferredoxin complex from a marine cyanobacterium provides insights into far-red light photoacclimation

Gisriel

Flesher

Shen

et al. 2022

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

Far-red light photoacclimation exhibited by some cyanobacteria allows these organisms to use the far-red region of the solar spectrum (700–800 nm) for photosynthesis. Part of this process includes the replacement of six photosystem I (PSI) subunits with isoforms that confer the binding of chlorophyll (Chl) f molecules that absorb far-red light (FRL). However, the exact sites at which Chl f molecules are bound are still challenging to determine. To aid in the identification of Chl f -binding sites, we solved the cryo-EM structure of PSI from far-red light-acclimated cells of the cyanobacterium Synechococcus sp. PCC 7335. We identified six sites that bind Chl f with high specificity and three additional sites that are likely to bind Chl f at lower specificity. All of these binding sites are in the core-antenna regions of PSI, and Chl f was not observed among the electron transfer cofactors. This structural analysis also reveals both conserved and nonconserved Chl f -binding sites, the latter of which exemplify the diversity in FRL-PSI among species. We found that the FRL–PSI structure also contains a bound soluble ferredoxin, PetF1, at low occupancy, which suggests that ferredoxin binds less transiently than expected according to the canonical view of ferredoxin-binding to facilitate electron transfer. We suggest that this may result from structural changes in FRL-PSI that occur specifically during FRL photoacclimation.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Identification Of Binding Sites For Chl Fmentioning

confidence: 98%

mentioning

confidence: 99%

See 1 more Smart Citation

Structure of a photosystem I-ferredoxin complex from a marine cyanobacterium provides insights into far-red light photoacclimation

Gisriel

Flesher

Shen

et al. 2022

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

show abstract

“…The one at shorter wavelengths is due to WL-PSII and the WL-PBSs that are maintained in FRL, in line with previous findings on another FaRLiP strain 17 . The band above 700 nm is due to FRL-PSII and the FRL-BCs 18 , while the shoulder extending up to 800 nm stems from the extremely red-shifted Chls f typical for FRL-PSI 16,18,25 . Upon 580-nm excitation, which is more selective for the bilins, the far-red band is more blue-shifted than upon 400-nm excitation due to a larger contribution from FRL-BCs.…”

Section: Resultsmentioning

confidence: 97%

The natural design for harvesting far-red light: the antenna increases both absorption and quantum efficiency of Photosystem II

Mascoli

Bersanini

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

Cyanobacteria carry out photosynthetic light-energy conversion using phycobiliproteins for light harvesting and the chlorophyll-rich photosystems for photochemistry. While most cyanobacteria only absorb visible photons, some of them can acclimate to harvest far-red light (FRL, 700-800 nm) by integrating chlorophyll f and d in their photosystems and producing red-shifted allophycocyanin. Chlorophyll f insertion enables the photosystems to use FRL but slows down charge separation, reducing photosynthetic efficiency. Here we demonstrate with time-resolved fluorescence spectroscopy that charge separation in chlorophyll-f-containing Photosystem II becomes faster in the presence of red-shifted allophycocyanin antennas. This is different from all known photosynthetic systems, where additional light-harvesting complexes slow down charge separation. Based on the available structural information, we propose a model for the connectivity between the phycobiliproteins and Photosystem II that qualitatively accounts for our spectroscopic data. This unique design is probably important for these cyanobacteria to efficiently switch between visible and far-red light.

show abstract

“…The present results and comparisons are also essential for interpreting and analyzing spectroscopic observations from studies that involve exchange of pigments. This can be physiological substitution of different chlorophylls, for example as part of a natural response of the photosynthetic apparatus to efficiently utilize far-red with red-shifted chlorophylls in place of Chl a, [35][36][37][38][39][40][41][42][43]…”

Section: Introductionmentioning

confidence: 99%

Electrostatic profiling of photosynthetic pigments: implications for directed spectral tuning

Sirohiwal

Pantazis

2021

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

Breaking the Red Limit: Efficient Trapping of Long-Wavelength Excitations in Chlorophyll-f-Containing Photosystem I

Cited by 27 publications

References 55 publications

Structure of a photosystem I-ferredoxin complex from a marine cyanobacterium provides insights into far-red light photoacclimation

Structure of a photosystem I-ferredoxin complex from a marine cyanobacterium provides insights into far-red light photoacclimation

The natural design for harvesting far-red light: the antenna increases both absorption and quantum efficiency of Photosystem II

Electrostatic profiling of photosynthetic pigments: implications for directed spectral tuning

Contact Info

Product

Resources

About