HHL1 is a chloroplast protein and participates in photodamage repair of PSII under high light. Mutants without HHL1 mutants show hypersensitivity to high light and drastically decreased PSII photosynthetic activity. HHL1 associates with the PSII core monomer complex through direct interaction with PSII core proteins CP43 and CP47, and also interacts with LQY1, which functions in the repair and reassembly of PSII.
