title: A possible evolutionary origin for the Mn4 cluster in photosystem II: from manganese superoxide dismutase to oxygen evolving complex.
abstract: The recently published X-ray absorption fine structure of photosystem II provides a more detailed architecture of the oxygen-evolving complex (OEC) and the surrounding amino acids. In this paper, a comparison between manganese superoxide dismutase, dinuclear manganese catalase enzymes and the oxygen evolving complex in photosystem II is reported. The author suggests that the development of oxygenic photosynthesis occurred in steps, the first of which involved only one manganese ion (Mn(II)) that oxidized two water molecules to hydrogen peroxide and then oxygen.
authors.affiliation: Dorna Institute of Science, No 83 Padadshahr, 14St. Ahwaz, Khozestan, Iran. mmnajafpour@yahoo.com
authors.forename: M Mahdi
authors.initials: MM
authors.lastname: Najafpour
mesh_terms: D019143:Evolution, Molecular; D008345:Manganese / Q000378:metabolism; D008958:Models, Molecular; D045332:Photosystem II Protein Complex / Q000737:chemistry / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000737:chemistry / Q000378:metabolism*
chemical_list: D045332:Photosystem II Protein Complex; D008345:Manganese; D013482:Superoxide Dismutase