The configurational space of LH complexes from higher plants – sensing and response to pH changes

ICFO – Institute of Photonic Sciences, Castelldefels, Spain

Project Description:

Plants prevent photodamage by dissipating excess absorbed sunlight as heat through a reversible feedback mechanism called energy-dependent quenching (qE). This process occurs in the photosynthetic membrane, where Light-Harvesting Complexes (LHCs) — pigment-binding membrane proteins — play a dual role. Under low light, LHCs harvest light and transfer excitation energy to the sites of photochemistry, while under strong light, a pH drop in the photosynthetic membrane lumen triggers their switch to a different conformation. In this conformation(s), the LHCs dissipate the solar energy absorbed in excess as heat. This project combines atomistic and coarse-grained molecular dynamics (MD) simulations, along with MD methods able to explicitly account for pH changes, to investigate how various gene products of the large family of LHCs sense and respond to pH in physiologically relevant conditions

Publications:

1. Liguori, Nicoletta, Sara RR Campos, António M. Baptista, and Roberta Croce. “Molecular anatomy of plant photoprotective switches: the sensitivity of PsbS to the environment, residue by residue.” The journal of physical chemistry letters 10, no. 8 (2019): 1737-1742.
   
2. Liguori, Nicoletta, Pengqi Xu, Ivo HM Van Stokkum, Bart Van Oort, Yinghong Lu, Daniel Karcher, Ralph Bock, and Roberta Croce. “Different carotenoid conformations have distinct functions in light-harvesting regulation in plants.” Nature communications 8, no. 1 (2017): 1994.
   
3. Liguori, Nicoletta, Xavier Periole, Siewert J. Marrink, and Roberta Croce. “From light-harvesting to photoprotection: structural basis of the dynamic switch of the major antenna complex of plants (LHCII).” Scientific reports 5, no. 1 (2015): 15661.