| Autor: |
Soichiro Seki, Tetsuko Nakaniwa, Pablo Castro-Hartmann, Kasim Sader, Akihiro Kawamoto, Hideaki Tanaka, Pu Qian, Genji Kurisu, Ritsuko Fujii |
| Jazyk: |
angličtina |
| Rok vydání: |
2022 |
| Předmět: |
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| Zdroj: |
BBA Advances, Vol 2, Iss , Pp 100064- (2022) |
| Druh dokumentu: |
article |
| ISSN: |
2667-1603 |
| DOI: |
10.1016/j.bbadva.2022.100064 |
| Popis: |
Light-harvesting complex II (LHCII) present in plants and green algae absorbs solar energy to promote photochemical reactions. A marine green macroalga, Codium fragile, exhibits the unique characteristic of absorbing blue-green light from the sun during photochemical reactions while being underwater owing to the presence of pigment-altered LHCII called siphonaxanthin–chlorophyll a/b-binding protein (SCP). In this study, we determined the structure of SCP at a resolution of 2.78 Å using cryogenic electron microscopy. SCP has a trimeric structure, wherein each monomer containing two lutein and two chlorophyll a molecules in the plant-type LHCII are replaced by siphonaxanthin and its ester and two chlorophyll b molecules, respectively. Siphonaxanthin occupies the binding site in SCP having a polarity in the trimeric inner core, and exhibits a distorted conjugated chain comprising a carbonyl group hydrogen bonded to a cysteine residue of apoprotein. These features suggest that the siphonaxanthin molecule is responsible for the characteristic green absorption of SCP. The replaced chlorophyll b molecules extend the region of the stromal side chlorophyll b cluster, spanning two adjacent monomers. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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