In vivo photosystem I reduction in thermophilic and mesophilic cyanobacteria: The thermal resistance of the process is limited by factors other than the unfolding of the partners
- Instituto de Bioquimica Vegetal y Fotosintesis, Universidad de Sevilla y CSIC, Centro Isla de la Cartuja, Americo Vespucio 49, E-41092 Sevilla (Spain)
Photosystem I reduction by plastocyanin and cytochrome c {sub 6} in cyanobacteria has been extensively studied in vitro, but much less information is provided on this process inside the cell. Here, we report an analysis of the electron transfer from both plastocyanin and cytochrome c {sub 6} to photosystem I in intact cells of several cyanobacterial species, including a comparative study of the temperature effect in mesophilic and thermophilic organisms. Our data show that cytochrome c {sub 6} reduces photosystem I by following a reaction mechanism involving complex formation, whereas the copper-protein follows a simpler collisional mechanism. These results contrast with previous kinetic studies in vitro. The effect of temperature on photosystem I reduction leads us to conclude that the thermal resistance of this process is determined by factors other than the proper stability of the protein partners.
- OSTI ID:
- 20710913
- Journal Information:
- Biochemical and Biophysical Research Communications, Vol. 334, Issue 1; Other Information: DOI: 10.1016/j.bbrc.2005.06.070; PII: S0006-291X(05)01313-6; Copyright (c) 2005 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
- Country of Publication:
- United States
- Language:
- English
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