1
|
Hao JF, Qi CH, Yu BY, Wang HY, Gao RY, Yamano N, Ma F, Wang P, Xin YY, Zhang CF, Yu LJ, Zhang JP. Light-Quality-Adapted Carotenoid Photoprotection in the Photosystem of Roseiflexus castenholzii. J Phys Chem Lett 2024:3470-3477. [PMID: 38512331 DOI: 10.1021/acs.jpclett.4c00593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
The photosystem of filamentous anoxygenic phototroph Roseiflexus (Rfl.) castenholzii comprises a light-harvesting (LH) complex encircling a reaction center (RC), which intensely absorbs blue-green light by carotenoid (Car) and near-infrared light by bacteriochlorophyll (BChl). To explore the influence of light quality (color) on the photosynthetic activity, we compared the pigment compositions and triplet excitation dynamics of the LH-RCs from Rfl. castenholzii was adapted to blue-green light (bg-LH-RC) and to near-infrared light (nir-LH-RC). Both LH-RCs bind γ-carotene derivatives; however, compared to that of nir-LH-RC (12%), bg-LH-RC contains substantially higher keto-γ-carotene content (43%) and shows considerably faster BChl-to-Car triplet excitation transfer (10.9 ns vs 15.0 ns). For bg-LH-RC, but not nir-LH-RC, selective photoexcitation of Car and the 800 nm-absorbing BChl led to Car-to-Car triplet transfer and BChl-Car singlet fission reactions, respectively. The unique excitation dynamics of bg-LH-RC enhances its photoprotection, which is crucial for the survival of aquatic anoxygenic phototrophs from photooxidative stress.
Collapse
Affiliation(s)
- Jin-Fang Hao
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China
| | - Chen-Hui Qi
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P. R. China
| | - Bu-Yang Yu
- National Laboratory of Solid State Microstructures & School of Physics, Nanjing University, Nanjing 210093, China
| | - Hao-Yi Wang
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China
| | - Rong-Yao Gao
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China
| | - Nami Yamano
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China
| | - Fei Ma
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P. R. China
| | - Peng Wang
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China
| | - Yue-Yong Xin
- Hangzhou Normal University, 2318 Yuhangtang Road, Cangqian, Yuhang District, Hangzhou 311121, Zhejiang, China
| | - Chun-Feng Zhang
- National Laboratory of Solid State Microstructures & School of Physics, Nanjing University, Nanjing 210093, China
| | - Long-Jiang Yu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P. R. China
| | - Jian-Ping Zhang
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China
| |
Collapse
|
2
|
Qi CH, Wang GL, Wang FF, Wang J, Wang XP, Zou MJ, Ma F, Madigan MT, Kimura Y, Wang-Otomo ZY, Yu LJ. Structural insights into the unusual core photocomplex from a triply extremophilic purple bacterium, Halorhodospira halochloris. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2024. [PMID: 38411333 DOI: 10.1111/jipb.13628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/17/2024] [Accepted: 02/03/2024] [Indexed: 02/28/2024]
Abstract
Halorhodospira (Hlr.) halochloris is a triply extremophilic phototrophic purple sulfur bacterium, as it is thermophilic, alkaliphilic, and extremely halophilic. The light-harvesting-reaction center (LH1-RC) core complex of this bacterium displays an LH1-Qy transition at 1,016 nm, which is the lowest-energy wavelength absorption among all known phototrophs. Here we report the cryo-EM structure of the LH1-RC at 2.42 Å resolution. The LH1 complex forms a tricyclic ring structure composed of 16 αβγ-polypeptides and one αβ-heterodimer around the RC. From the cryo-EM density map, two previously unrecognized integral membrane proteins, referred to as protein G and protein Q, were identified. Both of these proteins are single transmembrane-spanning helices located between the LH1 ring and the RC L-subunit and are absent from the LH1-RC complexes of all other purple bacteria of which the structures have been determined so far. Besides bacteriochlorophyll b molecules (B1020) located on the periplasmic side of the Hlr. halochloris membrane, there are also two arrays of bacteriochlorophyll b molecules (B800 and B820) located on the cytoplasmic side. Only a single copy of a carotenoid (lycopene) was resolved in the Hlr. halochloris LH1-α3β3 and this was positioned within the complex. The potential quinone channel should be the space between the LH1-α3β3 that accommodates the single lycopene but does not contain a γ-polypeptide, B800 and B820. Our results provide a structural explanation for the unusual Qy red shift and carotenoid absorption in the Hlr. halochloris spectrum and reveal new insights into photosynthetic mechanisms employed by a species that thrives under the harshest conditions of any phototrophic microorganism known.
Collapse
Affiliation(s)
- Chen-Hui Qi
- Key Laboratory of Photobiology, Photosynthesis Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Guang-Lei Wang
- Key Laboratory of Photobiology, Photosynthesis Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Fang-Fang Wang
- Zhangjiang Lab, National Facility for Protein Science in Shanghai, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201210, China
| | - Jie Wang
- Key Laboratory of Photobiology, Photosynthesis Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiang-Ping Wang
- Key Laboratory of Photobiology, Photosynthesis Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Mei-Juan Zou
- Key Laboratory of Photobiology, Photosynthesis Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Fei Ma
- Key Laboratory of Photobiology, Photosynthesis Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Michael T Madigan
- Department of Microbiology, School of Biological Sciences, Southern Illinois University, Carbondale, IL, 62901, USA
| | - Yukihiro Kimura
- Department of Agrobioscience, Graduate School of Agricultural Science, Kobe University, Nada, Kobe, 657-8501, Japan
| | | | - Long-Jiang Yu
- Key Laboratory of Photobiology, Photosynthesis Research Center, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| |
Collapse
|
3
|
Dong J, Wang P. Discovery of ultra-weakly coupled β-carotene J-aggregates by machine learning. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 310:123950. [PMID: 38277780 DOI: 10.1016/j.saa.2024.123950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 01/13/2024] [Accepted: 01/21/2024] [Indexed: 01/28/2024]
Abstract
Carotenoid aggregates are omnipresent in natural world and can be synthesized in hydrophilic environments. Despite different types of carotenoid aggregates have been reported hitherto, the way to predict the formation of carotenoid aggregates, i.e. H- or J-aggregates, is still challenging. Here, for the first time, we established machine learning models that can predict the formation behavior of carotenoid aggregates. The models are trained based on a database containing different types of carotenoid aggregates reported in the literatures. With the help of these machine learning models, we found a series of unknown types of β-carotene J-aggregates. These novel aggregates are ultra-weakly coupled and have absorption bands up to 700 nm, different from all the carotenoid aggregates reported previously. Our work demonstrates that the machine learning is a powerful tool to predict the formation behavior of carotenoid aggregates and can further lead into the discovery of new carotenoid aggregates for different applications.
Collapse
Affiliation(s)
- Jia Dong
- Department of Chemistry, Renmin University of China, Beijing 100872, People's Republic of China.
| | - Peng Wang
- Department of Chemistry, Renmin University of China, Beijing 100872, People's Republic of China.
| |
Collapse
|
4
|
Hao JF, Yamano N, Qi CH, Zhang Y, Ma F, Wang P, Yu LJ, Zhang JP. Carotenoid-Mediated Long-Range Energy Transfer in the Light Harvesting-Reaction Center Complex from Photosynthetic Bacterium Roseiflexus castenholzii. J Phys Chem B 2023; 127:10360-10369. [PMID: 37983555 DOI: 10.1021/acs.jpcb.3c07087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
The light harvesting-reaction center complex (LH-RC) of Roseiflexus castenholzii binds bacteriochlorophylls a (BChls a), B800 and B880, absorbing around 800 and 880 nm, respectively. We comparatively investigated the interband excitation energy transfer (EET) dynamics of the wild-type LH-RC (wt-LH-RC) of Rfl. castenholzii and its carotenoid (Car)-less mutant (m-LH-RC) and found that Car can boost the B800 → B880 EET rate from (2.43 ps)-1 to (1.75 ps)-1, accounting for 38% acceleration of the EET process. Interestingly, photoexcitation of wt-LH-RC at 800 nm induced pronounced excitation dynamics of Car despite the insufficient photon energy for direct Car excitation, a phenomenon which is attributed to the BChl-Car exciplex 1[B800(↑↑)···Car(↓↓)]*. Such an exciplex is suggested to play an essential role in promoting the B800 → B880 EET process, as corroborated by the recently reported cryo-EM structures of wt-LH-RC and m-LH-RC. The mechanism of Car-mediated EET will be helpful to deepen the understanding of the role of Car in bacterial photosynthesis.
Collapse
Affiliation(s)
- Jin-Fang Hao
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China
| | - Nami Yamano
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China
| | - Chen-Hui Qi
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P. R. China
| | - Yan Zhang
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China
| | - Fei Ma
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P. R. China
| | - Peng Wang
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China
| | - Long-Jiang Yu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P. R. China
| | - Jian-Ping Zhang
- Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing 100872, P. R. China
| |
Collapse
|
5
|
Sutherland GA, Pidgeon JP, Lee HKH, Proctor MS, Hitchcock A, Wang S, Chekulaev D, Tsoi WC, Johnson MP, Hunter CN, Clark J. Twisted Carotenoids Do Not Support Efficient Intramolecular Singlet Fission in the Orange Carotenoid Protein. J Phys Chem Lett 2023:6135-6142. [PMID: 37364284 DOI: 10.1021/acs.jpclett.3c01139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
Singlet exciton fission is the spin-allowed generation of two triplet electronic excited states from a singlet state. Intramolecular singlet fission has been suggested to occur on individual carotenoid molecules within protein complexes provided that the conjugated backbone is twisted out of plane. However, this hypothesis has been forwarded only in protein complexes containing multiple carotenoids and bacteriochlorophylls in close contact. To test the hypothesis on twisted carotenoids in a "minimal" one-carotenoid system, we study the orange carotenoid protein (OCP). OCP exists in two forms: in its orange form (OCPo), the single bound carotenoid is twisted, whereas in its red form (OCPr), the carotenoid is planar. To enable room-temperature spectroscopy on canthaxanthin-binding OCPo and OCPr without laser-induced photoconversion, we trap them in a trehalose glass. Using transient absorption spectroscopy, we show that there is no evidence of long-lived triplet generation through intramolecular singlet fission despite the canthaxanthin twist in OCPo.
Collapse
Affiliation(s)
- George A Sutherland
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K
| | - James P Pidgeon
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, U.K
| | - Harrison Ka Hin Lee
- SPECIFIC, Faculty of Science and Engineering, Swansea University, Swansea SA1 8EN, U.K
| | - Matthew S Proctor
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K
| | - Andrew Hitchcock
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K
| | - Shuangqing Wang
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, U.K
| | - Dimitri Chekulaev
- Department of Chemistry, University of Sheffield, Sheffield S3 7HF, U.K
| | - Wing Chung Tsoi
- SPECIFIC, Faculty of Science and Engineering, Swansea University, Swansea SA1 8EN, U.K
| | - Matthew P Johnson
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K
| | - C Neil Hunter
- Plants, Photosynthesis and Soil, School of Biosciences, University of Sheffield, Sheffield S10 2TN, U.K
| | - Jenny Clark
- Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, U.K
| |
Collapse
|