8qx5 is a 2 chain structure with sequence from Cyanobacteria. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
CROTO_NOSS1 Might act as a photo-protectant, protecting against damage induced by excess light via a process known as non-photochemical quenching (NPQ).[UniProtKB:P74102]