Part of a complex that function as an ATP-dependent zinc metallopeptidase. Involved in the thylakoid formation and in the removal of damaged D1 in the photosystem II, preventing cell death under high-intensity light conditions, but not involved in thermotolerance. Binds 1 zinc ion per subunit. Interacts with CHIP and FTSH5. Heterohexamers with FTSH1, FTSH5 and FTSH8. May also form homooligomers. Expressed in cotyledons, cauline and rosette leaves, stems, sepals, flovers and siliques. Very low in roots. Low expression in cotyledons, increasing with leaves development. By cold and high light. The conserved lumenal (CL) domain (83-161) is present only in some FtsH homologs from organisms performing oxygenic photosynthesis. The FTSH2 precursor is ubiquitinated by CHIP in the cytoplasm. Leaf-variegated. Mutations can be complemented by overexpression of FTSH8. The presence of both FTSH1 or FTSH5 (subunit type A) and FTSH2 or FTSH8 (subunit type B) is essential for an active complex formation. In the N-terminal section; belongs to the AAA ATPase family. In the C-terminal section; belongs to the peptidase M41 family.