Photosystem I: a search for green plant trimers
Roman Kouril1, Niels van Oosterwijk, Alevtyna E Yakushevska
1Department of Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.
Abstract:
Recent blue-native gel electrophoresis studies gave evidence for the existence of dimeric and trimeric PSI complexes in green plants. We used single particle electron microscopy to investigate all the larger particles from the thylakoid membrane of pea (Pisum sativum var. Charmette). Peak fractions with monomeric, dimeric and trimeric Photosystem I were obtained after solubilization with digitonin and size-exclusion chromatography. The analysis showed that only a few percent of dimers and trimers were present. In the best resolved trimers some of the monomers were oriented upside down. Many classes were fuzzy, indicating a non-specific or flexible orientation. From these results we conclude that the green plant PSI is monomeric within the green plant membrane.
Related Concept Videos
Photosystem II
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment molecules...
Photosystem I
Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...
Photosystems
Functioning of Photosystems
Photosystems contain many pigment molecules, such as chlorophylls and carotenoids, arranged in a particular organization across two domains — the antenna complex and the reaction center. The main aim of the pigment molecules...
The Z-Scheme of Electron Transport in Photosynthesis
What is Photosynthesis?
What is Photosynthesis?
Types of Organisms Based on their Modes of Nutrition
Broadly, there are two main categories of organisms based on their modes of nutrition — autotrophs and heterotrophs. An...

