Photoactivation of NH2OH‐treated leaves: reassembly of released extrinsic PS II polypeptides and religation of Mn into the polynuclear Mn catalyst of water oxidation

• Published in: FEBS letters 1985-11, Vol.192 (2), p.209-214
• Main Authors: Becker, David W., Callahan, Franklin E., Cheniae, G.M.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Cell structures and functions; Chloroplast, photosynthetic membrane and photosynthesis; DTT, dithiothreitol; Economic plant physiology; Fundamental and applied biological sciences. Psychology; LHCP, light-harvesting chlorophyll protein; Manganese; Molecular and cellular biology; Net assimilation, photosynthesis, carbon metabolism. Photorespiration, respiration, fermentation (anoxia, hypoxia); Nutrition. Photosynthesis. Respiration. Metabolism; O2 evolution; Photoactivation; Photosynthesis; Photosystem II polypeptide; PS, phptosystem; V o2 , rate of O2 evolution
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(85)80109-5

Inactivation of the water‐oxidizing enzyme by exposure of leaf segments to hydroxylamine results in a disassembly/perturbation of photosystem (PS) II extrinsic polypeptides (17>23 kDa) and solubilization of the tetra‐Mn complex. Religation of the tetra‐Mn complex, reassembly of these PS II extrinsic polypeptides with thylakoid membranes and reappearance of active water‐oxidizing activity all require light, and all are unaffected by inhibitors of protein synthesis and photophosphorylation. The results indicate, however, that the reassembly of these PS II extrinsic polypeptides into the multimeric water oxidizing enzyme occurs more rapidly than the photoligation of Mn as the tetra‐Mn complex.