Mechanism of photoprotection in the cyanobacterial ancestor of plant antenna proteins

0447354 - MBÚ 2016 RIV US eng J - Journal Article
Staleva, H. - Komenda, Josef - Shukla, Mahendra K. - Šlouf, V. - Kaňa, Radek - Polívka, Tomáš - Sobotka, Roman
Mechanism of photoprotection in the cyanobacterial ancestor of plant antenna proteins.
Nature Chemical Biology. Roč. 11, č. 4 (2015), s. 287-291. ISSN 1552-4450. E-ISSN 1552-4469
R&D Projects: GA ČR GBP501/12/G055; GA ČR(CZ) GA14-13967S; GA MŠMT ED2.1.00/03.0110
Institutional support: RVO:61388971 ; RVO:60077344
Keywords : photosystem II * fluorescence * chlorophyll
Subject RIV: BO - Biophysics; BO - Biophysics (BC-A)
Impact factor: 12.709, year: 2015

Plants collect light for photosynthesis using light-harvesting complexes (LHCs)-an array of chlorophyll proteins that are able to reversibly switch from harvesting to energy-dissipation mode to prevent damage of the photosynthetic apparatus. LHC antennae as well as other members of the LHC superfamily evolved from cyanobacterial ancestors called high light-inducible proteins (Hlips). Here, we characterized a purified Hlip family member HliD isolated from the cyanobacterium Synechocystis sp. PCC 6803. We found that the HliD binds chlorophyll-a (Chl-a) and beta-carotene and exhibits an energy-dissipative conformation. Using femtosecond spectroscopy, we demonstrated that the energy dissipation is achieved via direct energy transfer from a Chl-a Q(y) state to the beta-carotene S-1 state. We did not detect any cation of beta-carotene that would accompany Chl-a quenching. These results provide proof of principle that this quenching mechanism operates in the LHC superfamily and also shed light on the photoprotective role of Hlips and the evolution of LHC antennae.
Permanent Link: http://hdl.handle.net/11104/0249253