SPring-8

An additional water is introduced into the manganese cluster during the formation of the S3 state of photosystem II

During photosynthetic water oxidation, the Mn4Ca cluster in Photosystem II progresses through five intermediate Si (i = 0–4) states. X-ray crystallography studies have reported the insertion of one new O ligand during the formation of the S3 state, but recent studies question the...