Protein disulfide-isomerase probably involved upon formation of a complex with HHL1 in maintaining photosystem II (PSII) activity under high light by regulating repair and reassembly of PSII complexes. Catalyzes the rearrangement of -S-S- bonds in proteins. Binds 2 Zn(2+) ions per monomer. Interacts with the photosystem II core subunits (PubMed:21586683). Interacts with HHL1 (PubMed:24632535). More abundant in stroma-exposed thylakoids. Not induced by high-light treatment. Its sequence is related to the DnaJ family but lacks the J domain. The CR-type-like region is similar to CR-type zinc-fingers and was shown to bind zinc (PubMed:21586683). Lower maximum photochemical efficiency of photosystem II after high-light treatment. Belongs to the BSD2 chaperone family.