Photosystem manganese protein

Photosynthetic(II) chloroplasts, 2,773 Photosystem II dioxygen evolving centre manganese, 6, 586 manganese protein, 6, 590 Photothermography, 6, 118 Phthalamic acid, /V-(2-phenanthrolyl)-hydrolysis... 

A manganese protein appears to be involved in the dioxygen-producing reaction in photosystem II. 

Much effort has been put into the isolation, purification and reconstitution of both photosystems. Work on PSII has been concerned especially with the nature of the dioxygen-evolving site, which is thought to be a manganese protein. ESR studies on spinach chloroplasts have led to the postulate of the involvement in oxygen evolution of a pair (or possibly a tetramer) of antiferromagnetically... 

Leuschner C, Bricker TM. Interaction of the 33 kDa extrinsic protein with photosystem II Rebinding of the 33 kDa extrinsic protein to photosystem II membranes that contain four, two or zero manganese per photosystem II reaction center. Biochemistry 1996 35 4551-4557. 

In photosynthesis, water oxidation is accomplished by photosystem II (PSII), which is a large membrane-bound protein complex (158-161). To the central core proteins D1 and D2 are attached different cofactors, including a redox-active tyro-syl residue, tyrosine Z (Yz) (158-162), which is associated with a tetranuclear manganese complex (163). These components constitute the water oxidizing complex (WOC), the site in which the oxidation of water to molecular oxygen occurs (159, 160, 164). The organization is schematically shown in Fig. 18. 

Iodolabeling studies on photosystem II particles from higher plants and cyanobacteria (221) and on a PSII complex (227) specifically labeled the herbicide-binding protein. As 1 is believed to donate electrons to Z, the secondary electron donor which is believed to accept electrons from the photosynthetic manganese complex, these experiments indicate a role for this protein on the oxidizing side of PSII. Consequently, Z must at least be located near, if not in, the herbicidebinding polypeptide (222). 

R. Debus, ed. The Catal)4ic Manganese Cluster-Protein Ligation, in Photosystem II The Water/Plastoquinone Oxido-ReductaseinPhotosynthesisfeds.T. Wydrzynski and K. Satoh, Springer, The Netherlands, 2005, Chap. 11. 

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